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16 hoursMerge tag 'trace-v7.3-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ...
19 hoursring-buffer: Check resize_disabled before publishing the new subbuf orderDavid Carlier
ring_buffer_subbuf_order_set() stores the new order and only then walks the CPUs, returning -EBUSY if any of them has resizing disabled. A user mapped buffer has resizing disabled, and __rb_map_vma() reads buffer->subbuf_order without buffer->mutex, so an mmap of an already mapped CPU racing the failing order change sizes the mapping with the new order and inserts pages past the sub-buffer into the VMA. Check the CPUs before storing the new order. Cc: stable@vger.kernel.org Fixes: 117c39200d9d ("ring-buffer: Introducing ring-buffer mapping functions") Link: https://patch.msgid.link/20260912103938.1127021-1-devnexen@gmail.com Signed-off-by: David Carlier <devnexen@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
19 hourstracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizingVincent Donnefort
The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. Return SIZE_MAX from trace_buffer_desc_size() on nr_page_va overflow. Link: https://patch.msgid.link/20260911193937.602202-3-vdonnefort@google.com Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
19 hourstracing/remotes: Account for ring buffer page header in size calculationVincent Donnefort
trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the required pages because every ring buffer page contains a header (BUF_PAGE_HDR_SIZE). Account for that header to ensure allocated remote ring buffers aren't smaller than requested by the user. The newly introduced helper __calc_nr_pages_ring_buffer_desc() can return a value that overflows the descriptor nr_pages field (32 bits). Link: https://patch.msgid.link/20260911193937.602202-2-vdonnefort@google.com Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
19 hoursMerge tag 'timers-urgent-2026-09-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: - Fix clockevents replacement race when a broadcast device is replaced which may trigger a BUG() crash (朱恺乾 - Zhu Kaiqian) - Fix potential timerqueue ordering bug when rearming a queued timer with nonzero slack (Andrea Parri) * tag 'timers-urgent-2026-09-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimer: Use hard expiry when updating timers on the same base tick/broadcast: Plug clockevents replacement race
20 hoursMerge tag 'sched-urgent-2026-09-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: - Fix EEVDF se->max_slice value on enqueueing (Vincent Guittot) - Fix EEVDF augmented rb-trees re-balancing with multiple fields (Vincent Guittot) - In proxy scheduling, account cgroup CPU time to the execution context, not the scheduling context (Hui Su) - Likewise, call wq_worker_tick() for the execution context, not the scheduling context (Hui Su) * tag 'sched-urgent-2026-09-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Call wq_worker_tick() for the execution context sched: Account cgroup CPU time to the execution context sched/eevdf: Fix rb augmented with multi fields sched/eevdf: Fix augmented max_slice
20 hoursMerge tag 'perf-urgent-2026-09-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events fixes from Ingo Molnar - Fix sched_cb_list corruption on PMU callbacks that invoke list_del() during perf_event_overflow() calls (Thomas Richter) - Fix PEBS pt_regs->flags snapshot data that regressed with the introduction of adaptive PEBS v4 support (Dapeng Mi) - Fix possible drain_pebs() re-entry bug when intel_pmu_drain_pebs_buffer() is called from process context (Dapeng Mi) * tag 'perf-urgent-2026-09-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Prevent drain_pebs() reentry perf/x86/intel: Correct pt_regs->flags update for PEBS path perf/core: Allow list_del during perf_event_overflow()
42 hourstracing: Don't dereference trace_event_file in deferred trigger freeAli Ahmet Memiş
The enable_event trigger defers trace_event_put_ref() to the trigger free kthread, but the trace_event_file can already be freed when the instance is removed. Keep the trace_event_call directly in enable_trigger_data so the deferred free does not access the freed trace_event_file. Cc: stable@vger.kernel.org Fixes: e091351b3881 ("tracing: Delay module ref count for "enable_event" trigger") Reported-by: Alexander Gordeev <agordeev@linux.ibm.com> Closes: https://lore.kernel.org/all/20260828134340.2501683A24-agordeev@linux.ibm.com/ Link: https://patch.msgid.link/20260911155650.354844-1-aliamemis@disroot.org Signed-off-by: Ali Ahmet Memiş <aliamemis@disroot.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
42 hoursftrace: Use rcu_assign_pointer() for tmp_ops filter hashLeon Hwang
tmp_ops.func_hash->filter_hash is annotated __rcu, but update_ftrace_direct_mod() assigns hash to it directly. Sparse reports an address-space mismatch. Use rcu_assign_pointer() for the assignment. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260911142512.19344-1-leon.hwang@linux.dev Fixes: 50b35c9e50a8 ("ftrace: Use hash argument for tmp_ops in update_ftrace_direct_mod") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202609110704.Q3M5vCDV-lkp@intel.com/ Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daysring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()Sebastian Andrzej Siewior
rb_wake_up_waiters() is a irq_work callback which is initialized with init_irq_work(). As such it will be invoked in thread context on PREEMPT_RT. Invoking the callback in IRQ context on PREEMPT_RT is not an option due its usage of wake_up_all(). Since this callback may run in thread context, it needs to acquire ring_buffer_per_cpu::reader_lock with disabling interrupts and may not assume that they are disabled. Use raw_spinlock_irqsave() to acquire ring_buffer_per_cpu::reader_lock. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260911102152.YEtwkBj9@linutronix.de Fixes: 68282dd930ea3 ("ring-buffer: Fix resetting of shortest_full") Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Take trace_array reference when opening a tracer options fileSteven Rostedt
When a tracer option file is opened, it is passed a descriptor that points to an element on the trace_array's topts array. This element has information to find the trace array and other information. It uses this element to take a reference of the trace_array so that the trace_array does not get removed while this file is opened. Unfortunately, there's a race condition where the element itself could be freed by the removal of the instance the trace_array represents causing a use-after-free as this element that is used to find the trace_array to increment its reference counter is also freed when the instance is removed. To solve this, add a trace_array_tracer_options_get() helper function that will take the address of the element that is passed to the open function by the inode->i_private pointer and search all the trace_arrays under a lock to find the one that the element's address is in the range of the trace_arrays topts array elements. When a match happens, that trace_array's reference would be increased. Note, there's a race where if an admin was deleting and creating trace instances at the same time and the memory of the old trace_array's array matched the memory of the new trace_array that it could in theory open the option from the wrong trace array. But we do not care because it would be stupid to perform that kind of action. As long as the only thing that can happen is that the option from the wrong trace array is used and doesn't crash the kernel it will only make the user confused. But if they are doing something stupid like this, they are already confused, so no harm done. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260910221209.62dad8d3@robin Fixes: 7e2cfbd2d3c86 ("tracing: Have option files inc the trace array ref count") Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/linux-trace-kernel/20260902121918.5a9e9d1b@gandalf.local.home/ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Fix ring_buffer_read_page_size() kernel-docKarl Mehltretter
ring_buffer_read_page_size() takes a parameter named rpage, but its kernel-doc describes page. As a result, kernel-doc reports rpage as undescribed and page as an excess parameter description. Rename the documentation entry to match the function. Link: https://patch.msgid.link/20260909062917.89482-1-kmehltretter@gmail.com Fixes: dae8dda341d2 ("tracing: Fix subbuf resize races with trace_pipe_raw readers") Assisted-by: LLM Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()Thomas Weißschuh
While ftrace_set_clr_event() modifies its input buffer during parsing, before returning to the caller the buffer is supposed to be restored to its original state. This works correctly for the colon between the subsystem and event but not the colon at the beginning of :mod:. Restore the colon, so the :mod: trailer is not stripped after ftrace_set_clr_event(). Cc: stable@vger.kernel.org Fixes: 4c86bc531e60 ("tracing: Add :mod: command to enabled module events") Link: https://patch.msgid.link/20260908-tracing-cli-event-filter-v2-1-05396a3fb663@linutronix.de Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Fix memory corruption from a "STACKTRACE" histogram keyDonggeun Yoo
"cpu", "CPU", "stacktrace" and "STACKTRACE" are generic fields, defined with an offset and a size of zero so that the filter code can match them by name. parse_field() maps them onto their common_* equivalents for backward compatibility, but unlike the common_* names it hands the placeholder back to the caller instead of NULL. create_hist_field() takes a non-NULL field as a promise that the record carries a stacktrace and picks HIST_FIELD_FN_STACK, so the __data_loc word is read from offset 0, that is from common_type, and its low 16 bits are followed as an offset into the record. What is found there becomes the length of an unbounded memcpy. Pick an event whose id is small enough that the offset stays inside its own record and the length is a kernel text address: # cd /sys/kernel/tracing # echo 'hist:keys=STACKTRACE' > events/ftrace/print/trigger # echo hello > trace_marker Oops: general protection fault, probably for non-canonical address RIP: 0010:rb_next+0x23/0x60 </IRQ> RIP: 0010:memcpy+0xc/0x30 event_hist_trigger+0x2e7/0x12c0 Kernel panic - not syncing: Fatal exception in interrupt Leave the field NULL, which is what the comment above the branch says the code does and what common_stacktrace already does. FILTER_CPU and FILTER_COMM are left alone, their create_hist_field() branches never look at the field. Cc: stable@vger.kernel.org Fixes: 4b512860bdbd ("tracing: Rename stacktrace field to common_stacktrace") Link: https://patch.msgid.link/20260907155045.692664-3-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Fix memory corruption from the histogram stacktrace modifierDonggeun Yoo
parse_field() sets HIST_FIELD_FL_STACKTRACE from the ".stacktrace" modifier before it looks the field name up, and nothing afterwards checks that the name resolved to a field which holds a stacktrace. create_hist_field() picks HIST_FIELD_FN_STACK on the strength of the field pointer alone, which reads a __data_loc word from the record and follows its low 16 bits as an offset into the same record. event_hist_trigger() takes the first word there as an entry count and copies that many longs into a 31 entry array: n_entries = *stack; memcpy(entries, ++stack, n_entries * sizeof(unsigned long)); Neither end of that copy is bounded, and the count is whatever the event holds at the offset, so any field will do: # cd /sys/kernel/tracing/events/sched/sched_process_fork # echo 'hist:keys=parent_pid.stacktrace' > trigger # (true) BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:rb_insert_color+0x18/0x130 timerqueue_linked_add+0x7e/0xd0 enqueue_hrtimer+0x39/0xb0 __hrtimer_run_queues+0x10f/0x1f0 </IRQ> RIP: 0010:memcpy+0xc/0x30 event_hist_trigger+0x165/0x690 The timer interrupt landed on the rbtree the copy had already run over. No debug options are needed for this; KASAN reports the same write as an out-of-bounds read of 13835058055416381440 bytes. Documentation/trace/histogram.rst already states the rule, "must be a long[] type", so enforce it once the name has been resolved. Names which resolve to no field at all, "hitcount.stacktrace" and the common_* pseudo-fields, are refused for the same reason: they hold no stacktrace to read. Cc: stable@vger.kernel.org Fixes: cc5fc8bfc961 ("tracing/histogram: Add stacktrace type") Link: https://patch.msgid.link/20260907155045.692664-2-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Undo the registration when enabling the histogram trigger failsDonggeun Yoo
Commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers list") described how a trigger that is registered but not on file->triggers ends up freed while still on the global named_triggers list, and moved the registration down so that hist_trigger_enable() follows it immediately. One path still gets there. hist_trigger_enable() adds the trigger and takes it straight back out when the event cannot be enabled: list_add_tail_rcu(&data->list, &file->triggers); update_cond_flag(file); if (trace_event_trigger_enable_disable(file, 1) < 0) { list_del_rcu(&data->list); update_cond_flag(file); ret--; } so the list walk in hist_unregister_trigger() matches nothing, test stays NULL, and the ->free() that would call del_named_trigger() is skipped. out_unreg falls through to out_free, which frees the trigger anyway: BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0 Read of size 8 at addr ffff8880091d3160 by task init/1 find_named_trigger+0xac/0xc0 hist_register_trigger+0xc1/0xa00 event_hist_trigger_parse+0x3146/0x6af0 event_trigger_write+0xce/0x160 Freed by task 69: kfree+0x154/0x420 trigger_kthread_fn+0xfd/0x160 Leave the trigger where hist_unregister_trigger() can find it and let that undo the registration, which is the only code that knows all of what cmd_ops->init() took: the named list entry, the hist_pad reference, the reference on the trigger a named histogram is shared with, and the copied cmd_ops. It also pairs the failed trace_event_trigger_enable_disable(), whose sm_ref and buffered event reference are otherwise left behind. Since ->free() releases trigger_data and, for a trigger that does not share its histogram, hist_data with it, out_unreg can no longer fall through to out_free. For a trigger that does share, hist_register_trigger() has already destroyed the caller's hist_data, so the fall-through was reading freed memory there as well. Move the enable_timestamps check in hist_unregister_trigger() above the ->free() call for the same reason: hist_data does not outlive it once the trigger being removed is the one that owns it. Cc: stable@vger.kernel.org Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers") Reported-by: Sashiko AI <sashiko-bot@kernel.org> Closes: https://lore.kernel.org/linux-trace-kernel/20260907092944.3950E1F00A3D@smtp.kernel.org/ Link: https://patch.msgid.link/20260907124420.607097-3-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Take the reference before publishing the named histogram triggerDonggeun Yoo
event_hist_trigger_named_init() puts the trigger on the global named_triggers list and only then takes the reference on the trigger it shares its histogram with: data->ref++; save_named_trigger(data->named_data->name, data); ret = event_hist_trigger_init(data->named_data); if (ret < 0) { kfree(data->cmd_ops); data->cmd_ops = &trigger_hist_cmd; } return ret; event_hist_trigger_init() fails when alloc_hist_pad() cannot allocate, and nothing takes the trigger back off the list on the way out. event_hist_trigger_parse() frees it, and the next lookup by name reads the freed object: BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0 Read of size 8 at addr ffff888009346860 by task init/1 find_named_trigger+0xac/0xc0 hist_register_trigger+0xc1/0xa00 event_hist_trigger_parse+0x3146/0x6af0 event_trigger_write+0xce/0x160 Freed by task 67: kfree+0x154/0x420 trigger_kthread_fn+0xfd/0x160 Do the reference first and publish once it has succeeded, so that nothing which can fail runs after the trigger becomes findable. Cc: stable@vger.kernel.org Fixes: 7ab0fc61ce73 ("tracing: Move histogram trigger variables from stack to per CPU structure") Reported-by: Sashiko AI <sashiko-bot@kernel.org> Closes: https://lore.kernel.org/linux-trace-kernel/20260907092944.3950E1F00A3D@smtp.kernel.org/ Link: https://patch.msgid.link/20260907124420.607097-2-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Acked-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Set the trace clock before registering the histogram triggerDonggeun Yoo
hist_register_trigger() puts the trigger on the global named_triggers list in cmd_ops->init(), and only then sets the trace clock: if (data->cmd_ops->init) { ret = data->cmd_ops->init(data); if (ret < 0) goto out; } if (hist_data->enable_timestamps) { ret = tracing_set_clock(file->tr, hist_data->attrs->clock); if (ret) { hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock)); goto out; } The clock string is not checked anywhere before that call, so a named trigger using common_timestamp with an unknown clock fails after it has already become findable. event_hist_trigger_parse() then frees it without taking it off the list, and the next lookup by name reads the freed object: ~# cd /sys/kernel/tracing/events/sched/sched_switch ~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger bash: echo: write error: Invalid argument ~# echo 'hist:name=foo:keys=common_pid' > trigger BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0 Read of size 8 at addr ffff88800915d760 by task init/1 find_named_trigger+0xac/0xc0 hist_register_trigger+0xc1/0x900 event_hist_trigger_parse+0x3146/0x6af0 event_trigger_write+0xce/0x160 Freed by task 63: kfree+0x154/0x420 trigger_kthread_fn+0xfd/0x160 Set the clock before the trigger is registered, so that nothing which can fail runs after it is published, the way commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers list") moved the registration below the rest of the setup. tracing_set_filter_buffering() is reference counted, so the init failure path has to drop the reference that the clock block now takes first. Cc: stable@vger.kernel.org Fixes: a4072fe85ba3 ("tracing: Add a clock attribute for hist triggers") Link: https://patch.msgid.link/20260907091415.554535-1-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Fix typo "availabe" in commentHemanth Selam
Correct "availabe" to "available", reported by scripts/checkpatch.pl using the misspelling list in scripts/spelling.txt. Only touches comments, no code changes. Link: https://patch.msgid.link/20260907062608.13924-1-hemanth.selam@gmail.com Assisted-by: Cursor:claude-opus-5 Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Let histogram values keep the percent and graph modifiersDonggeun Yoo
The .percent and .graph modifiers exist only for histogram values, but a value carrying either of them has been rejected since v6.3. The example in Documentation/trace/histogram.rst, # echo 'hist:keys=prev_comm:vals=hitcount.percent:nohitcount' > \ events/sched/sched_switch/trigger returns -EINVAL. parse_field() sets the two flags only when the field is neither a key nor a variable, that is, only on a value: } else if (strncmp(modifier, "percent", 7) == 0) { if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY)) goto error; *flags |= HIST_FIELD_FL_PERCENT; __create_val_field() then rejects a value for carrying them, so no field can reach hist_trigger_print_val(), where both are implemented. commit e0213434fe3e ("tracing: Do not let histogram values have some modifiers") added the check after a value with .buckets oopsed in hist_field_name(). That happens because .buckets and .log2 make create_hist_field() build a nested field in operands[0] which hist_field_name() then walks into. The percent and graph flags do not create an operand and are not read by hist_field_name(); they are only used when printing a value. Stop rejecting the two flags on a value. The check for variables is left alone, where they are unreachable anyway because parse_field() rejects a variable carrying them first. With the two flags removed, the trigger above installs and prints as documented: { prev_comm: rcu_preempt } hitcount (%): 0.00 { prev_comm: init } hitcount (%): 99.98 Totals: Hits: 237896 Cc: stable@vger.kernel.org Fixes: e0213434fe3e ("tracing: Do not let histogram values have some modifiers") Link: https://patch.msgid.link/20260907052113.430818-1-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Keep the entry count when the histogram stats allocation failsDonggeun Yoo
print_entries() uses n_entries both as the number of sort entries and as its own return value, so the -ENOMEM it stores when the stats allocation fails overwrites the count that the cleanup still needs: n_entries = tracing_map_sort_entries(map, ...); if (n_entries < 0) return n_entries; ... if (!stats) { n_entries = -ENOMEM; goto out; } ... out: tracing_map_destroy_sort_entries(sort_entries, n_entries); tracing_map_destroy_sort_entries() takes an unsigned int and loops up to it, so -ENOMEM arrives as 4294967284. It walks an array of at most map->max_elts pointers and calls destroy_sort_entry(), which dereferences and frees, on whatever lies past the end. Reading the hist file of a trigger with a .percent value, with that allocation forced to fail: BUG: KASAN: vmalloc-out-of-bounds in tracing_map_destroy_sort_entries+0xa0/0xb0 Read of size 8 at addr ffffc90000045000 by task init/1 tracing_map_destroy_sort_entries+0xa0/0xb0 hist_show+0x6f7/0x1df0 seq_read_iter+0x2b8/0x1190 vfs_read+0x176/0xa40 The buggy address belongs to a 4-page vmalloc region starting at ffffc90000041000 allocated at tracing_map_sort_entries+0x5c/0xd50 A few pages further the fault is fatal. The registers at the oops confirm the bound: the loop's end pointer less the array start, over the pointer size, is 4294967284. Return the error in a separate variable and leave n_entries holding the count, the way tracing_map_sort_entries() does on its own error path. The stats block is only entered for a value carrying .percent or .graph, which __create_val_field() has rejected since v6.3, so this cannot be reached in mainline as it stands. It becomes reachable again with "tracing: hist: let values keep the percent and graph modifiers", so it should be applied first. Cc: stable@vger.kernel.org Fixes: abaa5258ce5e ("tracing: Add .percent suffix option to histogram values") Link: https://patch.msgid.link/20260907060323.480728-1-donggeunyoo.kernel@gmail.com Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/all/20260907053113.1CED91F00A3A@smtp.kernel.org/ Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Free histogram the field rejected for a bad modifierDonggeun Yoo
Writing a hist trigger whose value or variable carries a modifier that is not allowed there leaks the fields that were built for it. __create_val_field() takes the field from parse_expr() and stores it in hist_data->fields[] only after the modifier checks have run: hist_field = parse_expr(hist_data, file, field_str, flags, var_name, &n_subexprs); ... if (hist_field->flags & HIST_FIELD_FL_VAR) { if (hist_field->flags & (...)) goto err; } else { if (hist_field->flags & (...)) goto err; } hist_data->fields[val_idx] = hist_field; Both checks jump past that store, and the err label returns without freeing anything. The error unwinds to create_hist_data(), which calls destroy_hist_data() -> destroy_hist_fields(), and that reaches a field only by walking fields[]. A field that never got there is unreachable. commit e0213434fe3e ("tracing: Do not let histogram values have some modifiers") set ret to -EINVAL and fell through to the store, which left the field owned by fields[] and freed along with the rest of hist_data. Splitting the check into a value case and a variable case replaced that fall-through with a goto that skips it. With CONFIG_DEBUG_KMEMLEAK, 200 writes of # echo 'hist:keys=prev_pid:vals=next_pid.log2' > \ events/sched/sched_switch/trigger each correctly rejected with -EINVAL, leave 332 unreferenced objects (63744 bytes) reported at create_hist_field(); 200 install and remove cycles of a valid trigger leave none. A '.log2' field is two allocations, since create_hist_field() puts the plain field in operands[0] of the log2 field, and both are reported. Use destroy_hist_field() rather than __destroy_hist_field() so that operands[0] is freed as well. It returns early for HIST_FIELD_FL_VAR_REF, which is what an operand owned by hist_data->var_refs[] needs; the rejected field itself is never a var ref, because a var ref never carries a modifier flag. Cc: stable@vger.kernel.org Fixes: e30fbc618e97 ("tracing/histograms: Allow variables to have some modifiers") Link: https://patch.msgid.link/20260907034948.240387-1-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Free histogram the var ref when its initialization failsDonggeun Yoo
create_var_ref() allocates a VAR_REF hist_field and then calls init_var_ref() to fill it in. When that fails the field is leaked. commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") made destroy_hist_field() return early for HIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's var_refs[] array instead. create_var_ref() adds the field to that array only after init_var_ref() has succeeded, so on this path the field is in neither place and nothing frees it. The call was correct when it was written, before var refs were taken out of destroy_hist_field(). init_var_ref() cannot free it either. The caller owns the field, so init_var_ref() undoes only its own string allocations and leaves the field alone. Freeing it there would leave create_var_ref() passing freed memory to destroy_hist_field(), which reads its flags. Call __destroy_hist_field(), which frees the field without consulting the flag. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260906133352.3815019-1-donggeunyoo.kernel@gmail.com Fixes: 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing: Free histogram var refs regardless of how often they are referencedDonggeun Yoo
Using the same variable three or more times in one hist trigger leaks the variable reference and its strings when the trigger is removed. commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") made a trigger's var_refs[] array the only owner of a var ref: destroy_hist_field() returns early for HIST_FIELD_FL_VAR_REF, so the field expressions never destroy one. One entry, freed once, no count needed. commit 8bcebc77e85f ("tracing: Fix histogram code when expression has same var as value") then made repeated references share one object and added a count of them. Only the increment side exists, since those expressions still return early and never drop a reference, so __destroy_hist_field() sees how many references were created rather than how many are left. It frees when the decremented count is 0 or 1, so two references work and three or more leak. Sharing kept one array entry per object, and create_var_ref() searches and appends within a single trigger, so nothing outside it holds the object. Removing a trigger whose variables are still referenced is already refused by check_var_refs() with -EBUSY. Drop the count and free unconditionally. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260906124025.3550596-1-donggeunyoo.kernel@gmail.com Fixes: 8bcebc77e85f ("tracing: Fix histogram code when expression has same var as value") Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daysfunction_graph: Use the saved entry's size when reprinting itDonggeun Yoo
When a graph entry does not fit in the trace_seq, print_graph_entry() saves it in the iterator's fgraph_data and reprints it on the next read. The entry has already been consumed from the ring buffer by then, so the copy is all that is left of it. The copy is sized with iter->ent_size, which no longer describes the saved entry but whatever entry the iterator has moved on to. The argument count is derived from the same field, so a 72 byte entry saved and then reprinted ahead of a 48 byte return entry loses its arguments. Record the size next to the failure flag, so that the two are always set together, and restore it before reprinting. Cc: stable@vger.kernel.org Fixes: ff5c9c576e75 ("ftrace: Add support for function argument to graph tracer") Link: https://patch.msgid.link/20260906034406.1335316-1-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daysfgraph: Remove unused FGRAPH_MAX_INDEXDonggeun Yoo
FGRAPH_MAX_INDEX has no user, and it expands to FGRAPH_INDEX_SIZE and FGRAPH_RET_INDEX, neither of which is defined anywhere in the tree. It was added in that form by commit 91c46b0aa917 ("function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()"), which introduced the current data word layout under new names, so anything referencing it would have failed to build ever since. Remove it. Link: https://patch.msgid.link/20260905211922.1196366-1-donggeunyoo.kernel@gmail.com Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daysftrace: fork: Initialize function graph state before copy_exec_state()Jérémy Jean
dup_task_struct() copies the parent's task_struct, including ret_stack. ftrace_graph_init_task() clears the copied function graph state, but it currently runs after copy_exec_state(). For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, copy_process() reaches bad_fork_free and free_task() calls ftrace_graph_exit_task(). Since the child still carries the parent's ret_stack pointer, the unwind frees the parent's active function graph return stack. The parent subsequently accesses freed memory from function_graph_enter_regs(). KASAN reports: [ 22.190920] ================================================================== [ 22.195899] BUG: KASAN: slab-use-after-free in function_graph_enter_regs+0xa76/0xb90 [ 22.200747] Write of size 8 at addr ff110000054dc0a8 by task repro/1 [ 22.205134] [ 22.210770] CPU: 0 UID: 0 PID: 1 Comm: repro Not tainted 7.2.0-07732-g9328b3b03bdc-dirty #3 PREEMPT(lazy) [ 22.212576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 22.213750] Call Trace: [ 22.215271] <TASK> [ 22.216242] ? ftrace_stub_direct_tramp+0x10/0x10 [ 22.217774] dump_stack_lvl+0x4e/0x70 [ 22.220531] print_report+0x157/0x4b4 [ 22.223202] ? fixup_red_left+0x9/0x30 [ 22.224407] ? complete_report_info+0x83/0x110 [ 22.226679] ? function_graph_enter_regs+0xa76/0xb90 [ 22.228084] kasan_report+0xce/0x100 [ 22.230109] ? function_graph_enter_regs+0xa76/0xb90 [ 22.232860] ? stack_trace_save+0x4/0xd0 [ 22.234156] function_graph_enter_regs+0xa76/0xb90 [ 22.236090] ? kasan_save_stack+0x30/0x50 [ 22.237752] ? __pfx_function_graph_enter_regs+0x10/0x10 [ 22.238694] ? ring_buffer_lock_reserve+0x345/0xf80 [ 22.239628] ? stack_trace_save+0x4/0xd0 [ 22.242121] ? stack_trace_save+0x4/0xd0 [ 22.243588] ftrace_graph_func+0xda/0x160 [ 22.245362] ? ftrace_stub_direct_tramp+0x10/0x10 [ 22.246520] 0xffffffffa0000095 [ 22.250528] ? stack_trace_save+0x9/0xd0 [ 22.251757] ? ring_buffer_unlock_commit+0x11d/0x5c0 [ 22.253152] stack_trace_save+0x9/0xd0 [ 22.254264] kasan_save_stack+0x30/0x50 [ 22.273631] kasan_save_track+0x14/0x30 [ 22.276763] kasan_save_free_info+0x3b/0x70 [ 22.278296] __kasan_slab_free+0x43/0x70 [ 22.280157] kmem_cache_free+0xbf/0x3b0 [ 22.282963] ? ftrace_stub_direct_tramp+0x10/0x10 [ 22.284001] free_task+0xa2/0x160 [ 22.285699] ? ftrace_stub_direct_tramp+0x10/0x10 [ 22.286752] copy_process+0x2aae/0x7bc0 Initialize the child function graph state immediately after dup_task_struct(), before the first fallible operation. Cc: stable@vger.kernel.org Fixes: 6b1c66c9cca9 ("exec_state: relocate dumpable information") Reviewed-by: Bradley Morgan <include@grrlz.net> Link: https://patch.msgid.link/20260822195321.962383-2-Jeremy.Jean@oss.cyber.gouv.fr Assisted-by: Codex:gpt-5 Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 daystracing/user_events: Don't destroy fields when event removal failsHenry Martin
destroy_user_event() destroys the event's fields before attempting to remove the trace event call. If user_event_set_call_visible() fails, e.g. because the event is still enabled and trace_remove_event_call() returns -EBUSY, the event is left registered with an irreversibly destroyed field list. Any subsequent interaction with the event then operates on an empty field list while it is still fully visible in tracefs. Move the field destruction after the call removal, and splice the field list back onto the event when the removal fails so the event remains in a consistent state. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260904115223.2976446-1-bsdhenrymartin@gmail.com Fixes: 7f5a08c79df35 ("user_events: Add minimal support for trace_event into ftrace") Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com> Reviewed-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3 dayshrtimer: Use hard expiry when updating timers on the same baseAndrea Parri
Rearming a queued timer with nonzero slack can leave the timerqueue out of order. remove_and_enqueue_same_base() checks the new soft expiry against its neighbours' hard expiries, then stores the new hard expiry in the node without requeueing it. For example, with A at 10 and B at 20, rearming A at 11 with slack 30 passes the neighbour check but leaves A's hard expiry of 41 before B's 20. The same function also caches the soft expiry in base->expires_next when updating or inserting the first timer, giving next-event selection an earlier deadline than the queue head's hard expiry. Set the timer expiry before handling the queue. Use its stored hard expiry for the in-place ordering check and both updates to base->expires_next. The early update is safe because remove_and_enqueue_same_base() runs with base->cpu_base->lock held. The lock keeps the queue stable while hrtimer_can_update_in_place() checks the new expiry against both neighbours. If the check fails, timerqueue_linked_del() removes the node without comparing expiry values before it is reinserted. Fixes: eddffab8282e3 ("hrtimer: Keep track of first expiring timer per clock base") Fixes: 343f2f4dc5425 ("hrtimer: Try to modify timers in place") Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Assisted-by: LLM Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260910143442.2018-1-parri.andrea@gmail.com
4 daysMerge tag 'sysctl-7.03-fixes-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl Pull sysctl fix from Joel Granados: "This fell through the cracks during the latest merge window. There are no more CONFIG_PROC_SYSCTL uses after this fix: - Replace CONFIG_PROC_SYSCTL with CONFIG_SYSCTL CONFIG_SYSCTL is the config string that controls sysctl subsys" * tag 'sysctl-7.03-fixes-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: syscall_user_dispatch: Use CONFIG_SYSCTL for sysctl guard
4 dayssched/core: Call wq_worker_tick() for the execution contextHui Su
wq_worker_tick() accounts CPU time and detects CPU-intensive work for the kworker that is actually running. With proxy execution, rq->donor is the scheduling context while rq->curr is the execution context. Calling the hook with rq->donor can skip workqueue accounting when a kworker is executing on behalf of a donor task. It can also account a blocked kworker when the donor is a worker but rq->curr is the task actually executing. The former can delay WORKER_CPU_INTENSIVE handling and pool concurrency management, which can delay pending kernel work and userspace operations depending on it. Use rq->curr for the workqueue tick hook while retaining rq->donor for scheduler accounting. Fixes: af0c8b2bf67b ("sched: Split scheduler and execution contexts") Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Link: https://patch.msgid.link/20260902150208.1209922-2-sh_def@163.com
4 dayssched: Account cgroup CPU time to the execution contextHui Su
Proxy execution separates the scheduling context from the execution context. Commit aa4f74dfd42b ("sched: Fix runtime accounting w/ split exec & sched contexts") made per-task and thread-group runtime accounting follow the task that actually executes, while cgroup CPU usage is charged to the donor. When the donor and execution task belong to different cgroups, this makes a task's execution time count against a different cgroup from the one the task belongs to. Cgroup CPU usage should follow the execution context, matching the per-task, thread-group, and cgroup user/system accounting. Keep scheduling state associated with the donor, but charge cgroup CPU usage to rq->curr. A reproducer with the donor and execution task in separate cgroups showed the execution task accumulating runtime while cgroup CPU usage was charged to the donor's cgroup. With this change, the execution task's cgroup accumulates the CPU usage instead. The same behavior was verified with an RT donor and with legacy cpuacct accounting. Fixes: aa4f74dfd42b ("sched: Fix runtime accounting w/ split exec & sched contexts") Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: John Stultz <jstultz@google.com> Link: https://patch.msgid.link/20260904034707.268416-1-sh_def@163.com
4 dayssched/eevdf: Fix rb augmented with multi fieldsVincent Guittot
The eevdf rb tree maintains 3 augmented fields but only one is currently copied when balancing the tree. Add a more generic define that can be used when there are several augmented fields. In this case, we provide a function that takes care of copying all fields. Fixes: aef6987d8954 ("sched/eevdf: Propagate min_slice up the cgroup hierarchy") Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20260909150522.858312-1-vincent.guittot@linaro.org
4 dayssched/eevdf: Fix augmented max_sliceVincent Guittot
Similarly to se->min_slice, init se->max_slice with se->slice before enqueueing the entity so the augmented callback computes it correctly at parent level. Fixes: 6e3c0a4e1ad1 ("sched/fair: Fix lag clamp") Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20260907123855.1297976-1-vincent.guittot@linaro.org
4 daysperf/core: Allow list_del during perf_event_overflow()Thomas Richter
A PMU might use perf_sched_cb_inc() and perf_sched_cb_dec() interface to get the PMU call back function pmu::sched_task invoked at schedule in and schedule out. This is achieved by walking along the list anchored by sched_cb_list. The following scenario might lead to a list corruption. perf_pmu_sched_task() for_each_list_entry(..., &sched_cb_list) +--> __perf_pmu_sched_task() +--> event->pmu->sched_task()) +--> PMU_push_sample() +--> perf_event_overflow() +--> __perf_event_overflow() +--> pmu->stop() +--> perf_sched_cb_dec() remove entry from sched_cb_list while list node in use. This happens when ioctl(fd, PERF_EVENT_IOC_REFRESH, xxx) has been invoked and perf_event::event_limit hits zero. Prevent the list corruption and convert for_each_list_entry() to for_each_list_entry_safe(). Fixes: bd2756811766 ("perf: Rewrite core context handling") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260908105637.627004-1-tmricht@linux.ibm.com
5 daysMerge tag 'vfs-7.3-rc3.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - netfs: - Fix an uninitialized return value in netfs_unbuffered_write() when preparing the first subrequest fails - For partial unbuffered/DIO writes return the amount transferred rather than an error - Update i_size with the amount actually written when a partial transfer ends in an error - Fix a subrequest reference leak when the io_iter ends up empty - Handle netfs_alloc_subrequest() failure during unbuffered writes - Load all readahead folios into the rolling buffer upfront and drop the readahead references once the first subrequest is dispatched - Mark folios for copy-to-cache while issuing subrequests - Fix read progress reporting - afs: - Add the missing kunmap in the error path of afs_dir_search_bucket() - Fix a double kunmap in afs_edit_dir_remove() - Don't free an existing server's endpoint state when cleaning up a candidate server in afs_lookup_server() - Unbind peers removed from a server's address list - ufs: - Load the cylinder group metadata before creating the root dentry - Validate the cylinder group index and rotor positions before caching them - Treat an unreadable directory block as not empty - exec: - Close the close-on-exec files before taking exec_update_lock Closing a file can block on the filesystem, so a hung filesystem blocked everything that takes exec_update_lock and a FUSE server inspecting the calling process could deadlock - Drop the bprm loader before closing bprm->file in free_bprm() - exit: Hold a reference to thread_pid across proc_flush_pid() - reboot: Fix a use-after-free on cad_pid - nsfs: Keep the namespace tree fields out of the rcu_head used by kfree_rcu() - nstree: Check listing permission before taking a namespace reference in listns() - super: Return 0 when a nested thaw drops its hold while other freezers remain - ext4: Don't set I_METADATA_WRITEBACK during fastcommit replay - adfs: Free s_fs_info in ->kill_sb() - autofs: Free the inode info allocated in autofs_fill_super() when the root inode allocation fails - ovl: Return EINVAL instead of EIO on a user namespace mismatch now that it's a plain refusal and not an internal error - cachefiles: Don't cast the variable-length coherency data to a __be64 in the coherency tracepoint * tag 'vfs-7.3-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (28 commits) nstree: check listing permission before taking a namespace reference exec: do_close_on_exec() before taking exec_update_lock exit: hold a reference to thread_pid across proc_flush_pid fs: autofs: fix memory leak in autofs_fill_super() exec: Drop bprm loader before closing bprm->file afs: Clear stale peer app data after address list changes afs: Fix incorrect free in candidate cleanup in afs_lookup_server() afs: Fix double-unmap of directory block afs: Fix missing kunmap in afs_dir_search_bucket() ovl: return EINVAL instead of EIO in case of mismatched user_ns reboot: fix cad_pid use-after-free race cachefiles: Fix potential UAF/KASAN warning netfs: Fix read progress reporting netfs: Mark folios with COPY_TO_CACHE whilst issuing subreqs netfs: Fix readahead synchronisation issues by loading all folios upfront netfs: break unbuffered write when netfs_alloc_subrequest() fails netfs: Fix subreq ref leak netfs: Fix i_size update for partial transfer netfs: Fix error vs transferred passed to ->ki_complete() netfs: Fix unbuffered/DIO write partial transfer error return ...
5 daysMerge tag 'printk-for-7.3-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk fixes from Petr Mladek: - Use lazy irq_work for waking printk kthreads - Flush pending irq_work before destroying printk kthreads - Remove redundant WARN() when a printk kthread can't be created - Typo fix * tag 'printk-for-7.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk/nbcon: Change nbcon_irq_work to IRQ_WORK_LAZY printk/nbcon: Flush nbcon_irq_work in nbcon_free() console: fix /dev/kmsg reference in flags kernel doc printk: Don't WARN on kthread_run failure.
5 daysnstree: check listing permission before taking a namespace referenceNorbert Szetei
legitimize_ns() takes a reference on the candidate namespace before may_list_ns() has decided whether the caller may see it. The __free(ns_put) cleanup on the denied path can drop the last reference to a mount namespace while we still hold the rcu read lock, and put_mnt_ns() may sleep there. This is the same problem commit 2ec2aff3c8e2 ("ns: make sure reference are dropped outside of rcu lock") fixed for the put_user() path. Neither ns_requested() nor may_list_ns() needs a reference, both only look at the namespace type and at the caller's own namespaces, so do the checks first and take the reference last. Splat: Voluntary context switch within RCU read-side critical section! WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x238/0x2a0, CPU#5: a/3442 CPU: 5 UID: 1000 PID: 3442 Comm: a Not tainted 7.0.0-30-generic #30-Ubuntu PREEMPT(lazy) RIP: 0010:rcu_note_context_switch+0x238/0x2a0 Call Trace: <TASK> __schedule+0xcf/0x650 schedule+0x27/0x90 schedule_preempt_disabled+0x15/0x30 __mutex_lock.constprop.0+0x550/0xaf0 __mutex_lock_slowpath+0x13/0x20 mutex_lock+0x3b/0x50 exp_funnel_lock+0xb2/0x260 synchronize_rcu_expedited+0xe7/0x220 namespace_unlock+0x26a/0x320 put_mnt_ns+0xd3/0x120 mntns_put+0xe/0x20 do_listns+0x13e/0x560 __do_sys_listns+0x126/0x2d0 __x64_sys_listns+0x20/0x30 x64_sys_call+0x2366/0x2390 do_syscall_64+0x105/0x5a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> Fixes: 76b6f5dfb3fd ("nstree: add listns()") Signed-off-by: Norbert Szetei <norbert@doyensec.com> Link: https://patch.msgid.link/ABA32239-733B-438C-B95A-B13ED69FF0F3@doyensec.com Reviewed-by: Bradley Morgan <brads@mainlining.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
5 daysMerge branch 'for-7.4-trivial' into for-linusPetr Mladek
7 dayssyscall_user_dispatch: Use CONFIG_SYSCTL for sysctl guardKarl Mehltretter
Commit 8d75c338f0bc ("sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL") removed CONFIG_PROC_SYSCTL, but the sysctl added by commit 5b6e32ba7b59 ("syscall_user_dispatch: Add kernel.syscall_user_dispatch sysctl") is still guarded by it. Now that both commits are merged, kernel.syscall_user_dispatch is no longer registered. syscall_user_dispatch_allowed defaults to true. SUD therefore remains available, but administrators cannot disable new activations. Use CONFIG_SYSCTL for the guard and documentation. Fixes: 5b6e32ba7b59 ("syscall_user_dispatch: Add kernel.syscall_user_dispatch sysctl") Assisted-by: Codex:gpt-5.6-sol Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Joel Granados <joel.granados@kernel.org> Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Bradley Morgan <include@grrlz.net> Signed-off-by: Joel Granados <joel.granados@kernel.org>
7 daystick/broadcast: Plug clockevents replacement raceThomas Gleixner
朱恺乾 reported and decoded the following race condition when a broadcast device is replaced: CPUA CPUB __tick_broadcast_oneshot_control() bc = tick_broadcast_device.evtdev; tick_install_broadcast_device(dev) clockevents_exchange_device(cur, dev) shutdown(cur); detach(cur); cur->handler = noop; tick_broadcast_device.evtdev = dev; tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device. If the original broadcast device has a restricted interrupt affinity mask and the last CPU in that mask goes offline then the BUG() in tick_cleanup_dead_cpu() triggers because the clockevent device is not in detached state. The reason for this is that tick_install_broadcast_device() is not serialized vs. tick broadcast operations. The obvious cure is to serialize tick_install_broadcast_device() with tick_broadcast_lock against a concurrent tick broadcast operation. That requires to split clockevents_exchange_device() into two parts, one which does the exchange, shutdown and detach operation and the other which drops the module reference count. This is required because the module reference cannot be dropped while holding tick_broadcast_lock. Let clockevents_exchange_device() do both operations as before, but let the broadcast device code take the two step approach and do the device exchange under tick_broadcast_lock and drop the module reference count after releasing it. Fixes: f8381cba04ba ("[PATCH] tick-management: broadcast functionality") Reported-by: 朱恺乾 <zhukaiqian@xiaomi.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Bradley Morgan <brads@mainlining.org> Tested-by: 刘术高 <liushugao@xiaomi.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/87cymdsu0r.ffs@tglx
8 daysMerge tag 'trace-v7.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix several tracefs files that did not take the trace_array reference A trace instance can be created and destroyed in the tracefs "instances" directory via mkdir and rmdir respectively. The instance is represented by a trace_array descriptor. Most tracefs files pass the trace_array as the private data of the inode to the open/read/write functions. Since there is no locking between the time a task opens a file and the deletion of the instance (and the freeing of the trace_array), each open needs to get a reference to the trace_array and each close must remove it. An instance can't be removed if there's any reference taken on its trace_array. The open function uses trace_array_get() that takes a lock (preventing removal of instances) and iterates the list of all existing trace_arrays and if it finds a match, it takes the reference and releases the lock. If it doesn't find a match, it causes the open to return -ENODEV. There were some added files that did not take the trace_array reference on open that needed to be fixed. Sashiko also correctly pointed out that there were some files that took an address of an field or element of the trace_array which had a pointer back to the trace_array to take its reference on open. But this leaves a slight race between referencing this element to get the trace_array as the element itself could be freed. To solve this, some helper functions were created to look for trace_arrays with this field or element in the search so that the element did not have to be dereferenced before the trace_array's reference was taken. - Add a lock around ftrace_ops initialization When a ftrace_ops is first used by ftrace, some internal initialization is performed on the ops. But if multiple tasks were calling functions that did this initialization, it could race and perform doing the initialization more than once, corrupting the internal data. Add a lock in the initialization code to prevent this from happening. - Fix splice reads on mmapped buffers The logic in the ring buffer splice code for mmapped buffers is supposed to do a copy of the memory as the mapped buffers can't be given to splice. But there was an if statement within the copy code that would return a -1 if a request for a full page was done and it wasn't a partial read. This is because this logic was written before mmapped buffers existed and this case didn't make sense at the time. For mmapped buffers it makes perfect sense and by returning early can drop a lot of pages unnecessarily. - Have the persistent ring buffer validation check nr_subbufs Sashiko reported that the validation code was relying on the saved nr_subbufs to match the calculated nr_pages + 1 and if they were off, that the code could cause corruption. Sashiko is correct, and the saved nr_subbufs should be validated before assuming it is correct. - Do not allow more than one instance with the same name on cmdline If an admin were to add more than one trace instances with the same name they all would be created, but only the first one would be accessible via tracefs. This used to not be allowed but some restructuring of code has since made it possible. - Fix the race between subbuf resize and trace_pipe_raw readers If a task was reading trace_pipe_raw while another task was changing the ring buffer subbuf size, it could crash the reader. The trace_pipe_raw readers do get their own copy of the page from the buffer, but the code needs some restructuring to not have the resize of the subbuffers cause issues. - Cap the size of the mapped (static) ring buffer nr_pages The meta data used for ring buffer mapped buffers is 32 bit in size. A normal ring buffer could (in theory) have more than 4 billion pages. But this is not allowed by mapped buffers, so enforce it. * tag 'trace-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Use a macro for static buffer bits tracing: Fix comment in tracing_buffers_splice_read() ring-buffer: Prevent truncation of nr_pages / nr_subbufs ring-buffer: Cap static ring buffer nr_pages tracing: Fix subbuf resize races with trace_pipe_raw readers tracing: Fix to avoid creating trace instances with duplicate names ring-buffer: Add checking nr_subbufs to persistent ring buffer validation ring-buffer: Allow splice reads on static buffers tracing: Take trace_array reference when opening options file ftrace: Synchronize the initialization of ftrace_ops ftrace: Take trace_array reference before accessing its ftrace_ops tracing: Have show_event_filters/triggers files take trace array ref
8 daysMerge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds
Pull bpf fixes from Alexei Starovoitov: "This mainly contains verifier fixes that address bugs reported by Nicholas Carlini. - Fix incorrect non-NULL inference in pointer comparisons: pointer types that may be NULL at runtime, pointers with unbounded offsets, JMP32 comparisons with zero, and imprecise zero registers (Eduard Zingerman) - Fix precision tracking for half-dead zero spills, ld_abs/ld_ind implicit subprog exit, bpf_loop() callbacks, linked scalar ids and NULL call arguments (Eduard Zingerman) - Reject BPF_PSEUDO_FUNC reference to the main program, fix zero extension of arena 32-bit cmpxchg, don't rewrite bpf_fastcall patterns entered by a jump (Eduard Zingerman) - Fix percpu map update and BPF_F_CPU validation with sparse CPU IDs (Hui Su) - Fix NULL-ptr-derefs in bpf_snprintf_btf() for void and VAR types, and reject key-less BTF for hash maps (Jiayuan Chen) - Various fixes (Kumar Kartikeya Dwivedi): - Fix out-of-bounds access in disassembler on invalid LDSX instruction - mark siginfo of signal tracepoints as scalar and sched_process_wait argument as nullable - mark faultable stack helpers as sleepable - reject tail calls and legacy packet loads from callbacks - enforce rbtree callback lock restrictions for resilient locks - require MEM_PERCPU for percpu kptr stores - clear NON_OWN_REF after RCU protection ends - mark NULL kptr stores precise - preserve inner map identity in callback frames - reject non-scalar bpf_loop() iteration counts - Fix trampoline allocation slowdown on x86 by using EXECMEM_MODULE_DATA (Mike Rapoport) - Keep bpf_refcount_acquire() nullable for borrowed RCU kptrs and reject untrusted allocated-object pointers (Ning Ding) - Fix special fields handling in recycled rhtab elements (Nuoqi Gui, Yuan Chen)" * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (86 commits) bpf, riscv: Make arena support depend on ZACAS selftests/bpf: Test pointer bpf_loop iteration count rejection bpf: Reject non-scalar bpf_loop iteration counts bpf: use mark_arg_precision() in check_mem_size_reg() bpf: propagate mark_chain_precision() errors out of loop_flag_is_zero() selftests/bpf: precision of a NULL global subprogram BTF_ID argument bpf: mark a NULL BTF_ID argument of a global subprogram precise selftests/bpf: precision of a NULL kfunc argument bpf: mark a NULL kfunc argument precise selftests/bpf: precision of a NULL global subprogram memory argument bpf: mark a NULL memory argument of a call precise selftests/bpf: precision of a NULL helper argument bpf: mark a NULL call argument precise selftests/bpf: Test inner map identities in callbacks bpf: Preserve inner map identity in callback frames selftests/bpf: Test imprecise scalar kptr stores bpf: Mark NULL kptr stores precise selftests/bpf: Test rhtab kptr cancellation semantics bpf: Cancel special fields when recycling rhtab elements selftests/bpf: Test timer field on recycled rhtab element ...
8 daysMerge tag 'sched-urgent-2026-09-06' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: - Fix a timestamping bug in pick_task_fair() and yield_task_fair() (Zhan Xusheng) - Skip migrate-disabled tasks when picking a push candidate in the RT and DL schedulers (Seiji Nishikawa) - Skip rq->avg_idle update without a valid idle_stamp (Shubhang Kaushik) - Fix throttling bug in throttle_cfs_rq(), caused by the recent single-runqueue conversion (Wanwu Li) - Fix bandwidth calculation bug in distribute_cfs_runtime(), caused by the single-runqueue conversion (Wanwu Li) - Don't make x86 ITMT enablement depend on debugfs (Mario Limonciello) - Avoid creating misfits during cache-aware load-balancing on hybrid systems (Tim Chen) * tag 'sched-urgent-2026-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Avoid creating misfits during cache-aware balancing x86/itmt: Don't make ITMT enablement depend on debugfs sched/fair: Use cfs_rq->h_curr in distribute_cfs_runtime() sched/fair: Use cfs_rq->h_curr in throttle_cfs_rq() sched/core: Skip rq->avg_idle update without a valid idle_stamp sched/rt,dl: Skip migrate-disabled tasks when picking a push candidate sched/fair: Use update_curr_eevdf() for the remaining root cfs_rq callers
8 daysMerge tag 'perf-urgent-2026-09-06' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events fixes from Ingo Molnar: - Skip empty AUX records with only format flags (Leo Yan) - Fix use-after-free when perf mmap() revival races with the last munmap() (Yilin Zhang, Weiming Shi) * tag 'perf-urgent-2026-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix use-after-free when perf mmap() revival races with the last munmap() perf/core: Skip empty AUX records with only format flags
8 daysMerge tag 'locking-urgent-2026-09-06' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Ingo Molnar: - Fix a softirq processing delay bug in local_interrupt_disable(), which should mostly only affect the Rust runtime (Boqun Feng) - Remove the hardirq_disable_count() function which caused the previous bug and is now unused & unnecessary (Boqun Feng) - lockdep: Invalidate stale class_cache entries for zapped classes (Eric Dumazet) - Fix rt_mutex specific futex scheduling helpers (Sebastian Andrzej Siewior) - Fix rcuwait use-after-free race during futex requeue PI (Yao Kai) * tag 'locking-urgent-2026-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Prevent rcuwait use-after-free during requeue PI futex: Provide rt_mutex_.*_schedule() equivalents for futex scheduling locking/lockdep: Invalidate stale class_cache entries for zapped classes preempt: Remove hardirq_disable_count() interrupt: Disable interrupt before modifying hardirq_disable counter
8 daysbpf: Reject non-scalar bpf_loop iteration countsKumar Kartikeya Dwivedi
bpf_loop() declares its nr_loops argument as ARG_ANYTHING. Privileged programs may pass pointer values to such arguments, so check_func_arg() lets a pointer-valued R1 reach the helper-specific checks. Since commit bb124da69c47 ("bpf: keep track of max number of bpf_loop callback iterations"), the verifier marks R1 precise and reads its upper bound to limit callback simulation. Precision backtracking only accepts scalar registers, so passing a pointer instead triggers the "backtracking misuse" verifier warning. Kernels with panic_on_warn enabled subsequently panic. Introduce ARG_SCALAR for helper arguments that only accept scalar values and use it for bpf_loop() nr_loops. Generic helper argument validation then rejects pointers before loop inlining and precision processing. Fixes: bb124da69c47 ("bpf: keep track of max number of bpf_loop callback iterations") Reported-by: syzbot+7b47f87674e9a1569110@syzkaller.appspotmail.com Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://patch.msgid.link/20260905014735.1452988-2-memxor@gmail.com Closes: https://lore.kernel.org/bpf/6a9ad24c.b5d4176b.238c3e.0001.GAE@google.com/ Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
9 daystreewide: refresh kmalloc_obj() conversionsKees Cook
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
9 daysbpf: use mark_arg_precision() in check_mem_size_reg()Eduard Zingerman
Use newly added mark_arg_precision() helper in check_mem_size_reg(). Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-10-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
9 daysbpf: propagate mark_chain_precision() errors out of loop_flag_is_zero()Eduard Zingerman
Stop verification if mark_chain_precision() fails when called from loop_flag_is_zero(). No functional change intended for the paths where backtracking succeeds. Fixes: 1ade23711971 ("bpf: Inline calls to bpf_loop when callback is known") Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-9-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>