Pull hardening updates from Kees Cook: - Introduce and start using TRAILING_OVERLAP() helper for fixing embedded flex array instances (Gustavo A. R. Silva) - mux: Convert mux_control_ops to a flex array member in mux_chip (Thorsten Blum) - string: Group str_has_prefix() and strstarts() (Andy Shevchenko) - Remove KCOV instrumentation from __init and __head (Ritesh Harjani, Kees Cook) - Refactor and rename stackleak feature to support Clang - Add KUnit test for seq_buf API - Fix KUnit fortify test under LTO * tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits) sched/task_stack: Add missing const qualifier to end_of_stack() kstack_erase: Support Clang stack depth tracking kstack_erase: Add -mgeneral-regs-only to silence Clang warnings init.h: Disable sanitizer coverage for __init and __head kstack_erase: Disable kstack_erase for all of arm compressed boot code x86: Handle KCOV __init vs inline mismatches arm64: Handle KCOV __init vs inline mismatches s390: Handle KCOV __init vs inline mismatches arm: Handle KCOV __init vs inline mismatches mips: Handle KCOV __init vs inline mismatch powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON configs/hardening: Enable CONFIG_KSTACK_ERASE stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth stackleak: Rename STACKLEAK to KSTACK_ERASE seq_buf: Introduce KUnit tests string: Group str_has_prefix() and strstarts() kunit/fortify: Add back "volatile" for sizeof() constants acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings ...
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull non-MM updates from Andrew Morton:
- "hung_task: extend blocking task stacktrace dump to semaphore" from
Lance Yang enhances the hung task detector.
The detector presently dumps the blocking tasks's stack when it is
blocked on a mutex. Lance's series extends this to semaphores
- "nilfs2: improve sanity checks in dirty state propagation" from
Wentao Liang addresses a couple of minor flaws in nilfs2
- "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn
fixes a couple of issues in the gdb scripts
- "Support kdump with LUKS encryption by reusing LUKS volume keys" from
Coiby Xu addresses a usability problem with kdump.
When the dump device is LUKS-encrypted, the kdump kernel may not have
the keys to the encrypted filesystem. A full writeup of this is in
the series [0/N] cover letter
- "sysfs: add counters for lockups and stalls" from Max Kellermann adds
/sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and
/sys/kernel/rcu_stall_count
- "fork: Page operation cleanups in the fork code" from Pasha Tatashin
implements a number of code cleanups in fork.c
- "scripts/gdb/symbols: determine KASLR offset on s390 during early
boot" from Ilya Leoshkevich fixes some s390 issues in the gdb
scripts
* tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits)
llist: make llist_add_batch() a static inline
delayacct: remove redundant code and adjust indentation
squashfs: add optional full compressed block caching
crash_dump, nvme: select CONFIGFS_FS as built-in
scripts/gdb/symbols: determine KASLR offset on s390 during early boot
scripts/gdb/symbols: factor out pagination_off()
scripts/gdb/symbols: factor out get_vmlinux()
kernel/panic.c: format kernel-doc comments
mailmap: update and consolidate Casey Connolly's name and email
nilfs2: remove wbc->for_reclaim handling
fork: define a local GFP_VMAP_STACK
fork: check charging success before zeroing stack
fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
fork: clean-up ifdef logic around stack allocation
kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count
kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count
x86/crash: make the page that stores the dm crypt keys inaccessible
x86/crash: pass dm crypt keys to kdump kernel
Revert "x86/mm: Remove unused __set_memory_prot()"
crash_dump: retrieve dm crypt keys in kdump kernel
...
proc_mem_open() can return an errno, NULL, or mm_struct*. If it fails to
acquire mm, it returns NULL, but the caller does not check for the case
when the return value is NULL.
The following conditions lead to failure in acquiring mm:
- The task is a kernel thread (PF_KTHREAD)
- The task is exiting (PF_EXITING)
Changes:
- Add documentation comments for the return value of proc_mem_open().
- Add checks in the caller to return -ESRCH when proc_mem_open()
returns NULL.
Link: https://lkml.kernel.org/r/20250404063357.78891-1-superman.xpt@gmail.com
Reported-by: syzbot+f9238a0a31f9b5603fef@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000f52642060d4e3750@google.com
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Felix Moessbauer <felix.moessbauer@siemens.com>
Cc: Jeff layton <jlayton@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
try_lookup_noperm() and d_hash_and_lookup() are nearly identical. The former does some validation of the name where the latter doesn't. Outside of the VFS that validation is likely valuable, and having only one exported function for this task is certainly a good idea. So make d_hash_and_lookup() local to VFS files and change all other callers to try_lookup_noperm(). Note that the arguments are swapped. Signed-off-by: NeilBrown <neilb@suse.de> Link: https://lore.kernel.org/r/20250319031545.2999807-6-neil@brown.name Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull non-MM updates from Andrew Morton: - The series "powerpc/crash: use generic crashkernel reservation" from Sourabh Jain changes powerpc's kexec code to use more of the generic layers. - The series "get_maintainer: report subsystem status separately" from Vlastimil Babka makes some long-requested improvements to the get_maintainer output. - The series "ucount: Simplify refcounting with rcuref_t" from Sebastian Siewior cleans up and optimizing the refcounting in the ucount code. - The series "reboot: support runtime configuration of emergency hw_protection action" from Ahmad Fatoum improves the ability for a driver to perform an emergency system shutdown or reboot. - The series "Converge on using secs_to_jiffies() part two" from Easwar Hariharan performs further migrations from msecs_to_jiffies() to secs_to_jiffies(). - The series "lib/interval_tree: add some test cases and cleanup" from Wei Yang permits more userspace testing of kernel library code, adds some more tests and performs some cleanups. - The series "hung_task: Dump the blocking task stacktrace" from Masami Hiramatsu arranges for the hung_task detector to dump the stack of the blocking task and not just that of the blocked task. - The series "resource: Split and use DEFINE_RES*() macros" from Andy Shevchenko provides some cleanups to the resource definition macros. - Plus the usual shower of singleton patches - please see the individual changelogs for details. * tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits) mailmap: consolidate email addresses of Alexander Sverdlin fs/procfs: fix the comment above proc_pid_wchan() relay: use kasprintf() instead of fixed buffer formatting resource: replace open coded variant of DEFINE_RES() resource: replace open coded variants of DEFINE_RES_*_NAMED() resource: replace open coded variant of DEFINE_RES_NAMED_DESC() resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED() samples: add hung_task detector mutex blocking sample hung_task: show the blocker task if the task is hung on mutex kexec_core: accept unaccepted kexec segments' destination addresses watchdog/perf: optimize bytes copied and remove manual NUL-termination lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap() lib/interval_tree: skip the check before go to the right subtree lib/interval_tree: add test case for span iteration lib/interval_tree: add test case for interval_tree_iter_xxx() helpers lib/rbtree: add random seed lib/rbtree: split tests lib/rbtree: enable userland test suite for rbtree related data structure checkpatch: describe --min-conf-desc-length scripts/gdb/symbols: determine KASLR offset on s390 ...
Pull timer core updates from Thomas Gleixner: - Fix a memory ordering issue in posix-timers Posix-timer lookup is lockless and reevaluates the timer validity under the timer lock, but the update which validates the timer is not protected by the timer lock. That allows the store to be reordered against the initialization stores, so that the lookup side can observe a partially initialized timer. That's mostly a theoretical problem, but incorrect nevertheless. - Fix a long standing inconsistency of the coarse time getters The coarse time getters read the base time of the current update cycle without reading the actual hardware clock. NTP frequency adjustment can set the base time backwards. The fine grained interfaces compensate this by reading the clock and applying the new conversion factor, but the coarse grained time getters use the base time directly. That allows the user to observe time going backwards. Cure it by always forwarding base time, when NTP changes the frequency with an immediate step. - Rework of posix-timer hashing The posix-timer hash is not scalable and due to the CRIU timer restore mechanism prone to massive contention on the global hash bucket lock. Replace the global hash lock with a fine grained per bucket locking scheme to address that. - Rework the proc/$PID/timers interface. /proc/$PID/timers is provided for CRIU to be able to restore a timer. The printout happens with sighand lock held and interrupts disabled. That's not required as this can be done with RCU protection as well. - Provide a sane mechanism for CRIU to restore a timer ID CRIU restores timers by creating and deleting them until the kernel internal per process ID counter reached the requested ID. That's horribly slow for sparse timer IDs. Provide a prctl() which allows CRIU to restore a timer with a given ID. When enabled the ID pointer is used as input pointer to read the requested ID from user space. When disabled, the normal allocation scheme (next ID) is active as before. This is backwards compatible for both kernel and user space. - Make hrtimer_update_function() less expensive. The sanity checks are valuable, but expensive for high frequency usage in io/uring. Make the debug checks conditional and enable them only when lockdep is enabled. - Small updates, cleanups and improvements * tag 'timers-core-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) selftests/timers: Improve skew_consistency by testing with other clockids timekeeping: Fix possible inconsistencies in _COARSE clockids posix-timers: Drop redundant memset() invocation selftests/timers/posix-timers: Add a test for exact allocation mode posix-timers: Provide a mechanism to allocate a given timer ID posix-timers: Dont iterate /proc/$PID/timers with sighand:: Siglock held posix-timers: Make per process list RCU safe posix-timers: Avoid false cacheline sharing posix-timers: Switch to jhash32() posix-timers: Improve hash table performance posix-timers: Make signal_struct:: Next_posix_timer_id an atomic_t posix-timers: Make lock_timer() use guard() posix-timers: Rework timer removal posix-timers: Simplify lock/unlock_timer() posix-timers: Use guards in a few places posix-timers: Remove SLAB_PANIC from kmem cache posix-timers: Remove a few paranoid warnings posix-timers: Cleanup includes posix-timers: Add cond_resched() to posix_timer_add() search loop posix-timers: Initialise timer before adding it to the hash table ...
proc_pid_wchan() used to report kernel addresses to user space but that is
no longer the case today. Bring the comment above proc_pid_wchan() in
sync with the implementation.
Link: https://lkml.kernel.org/r/20250319210222.1518771-1-bvanassche@acm.org
Fixes: b2f73922d119 ("fs/proc, core/debug: Don't expose absolute kernel addresses via wchan")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All the big Linux distros enable CONFIG_SCHED_DEBUG, because the various features it provides help not just with kernel development, but with system administration and user-space software development as well. Reflect this reality and enable this functionality unconditionally. Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317104257.3496611-4-mingo@kernel.org