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2023-01-07tracing: Fix infinite loop in tracing_read_pipe on overflowed print_trace_lineYang Jihong
commit c1ac03af6ed45d05786c219d102f37eb44880f28 upstream. print_trace_line may overflow seq_file buffer. If the event is not consumed, the while loop keeps peeking this event, causing a infinite loop. Link: https://lkml.kernel.org/r/20221129113009.182425-1-yangjihong1@huawei.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Fixes: 088b1e427dbba ("ftrace: pipe fixes") Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07gcov: add support for checksum fieldRickard x Andersson
commit e96b95c2b7a63a454b6498e2df67aac14d046d13 upstream. In GCC version 12.1 a checksum field was added. This patch fixes a kernel crash occurring during boot when using gcov-kernel with GCC version 12.2. The crash occurred on a system running on i.MX6SX. Link: https://lkml.kernel.org/r/20221220102318.3418501-1-rickaran@axis.com Fixes: 977ef30a7d88 ("gcov: support GCC 12.1 and newer compilers") Signed-off-by: Rickard x Andersson <rickaran@axis.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Martin Liska <mliska@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07acct: fix potential integer overflow in encode_comp_t()Zheng Yejian
[ Upstream commit c5f31c655bcc01b6da53b836ac951c1556245305 ] The integer overflow is descripted with following codes: > 317 static comp_t encode_comp_t(u64 value) > 318 { > 319 int exp, rnd; ...... > 341 exp <<= MANTSIZE; > 342 exp += value; > 343 return exp; > 344 } Currently comp_t is defined as type of '__u16', but the variable 'exp' is type of 'int', so overflow would happen when variable 'exp' in line 343 is greater than 65535. Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Jinhao <zhangjinhao2@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-07blktrace: Fix output non-blktrace event when blk_classic option enabledYang Jihong
[ Upstream commit f596da3efaf4130ff61cd029558845808df9bf99 ] When the blk_classic option is enabled, non-blktrace events must be filtered out. Otherwise, events of other types are output in the blktrace classic format, which is unexpected. The problem can be triggered in the following ways: # echo 1 > /sys/kernel/debug/tracing/options/blk_classic # echo 1 > /sys/kernel/debug/tracing/events/enable # echo blk > /sys/kernel/debug/tracing/current_tracer # cat /sys/kernel/debug/tracing/trace_pipe Fixes: c71a89615411 ("blktrace: add ftrace plugin") Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-07perf: Fix possible memleak in pmu_dev_alloc()Chen Zhongjin
[ Upstream commit e8d7a90c08ce963c592fb49845f2ccc606a2ac21 ] In pmu_dev_alloc(), when dev_set_name() failed, it will goto free_dev and call put_device(pmu->dev) to release it. However pmu->dev->release is assigned after this, which makes warning and memleak. Call dev_set_name() after pmu->dev->release = pmu_dev_release to fix it. Device '(null)' does not have a release() function... WARNING: CPU: 2 PID: 441 at drivers/base/core.c:2332 device_release+0x1b9/0x240 ... Call Trace: <TASK> kobject_put+0x17f/0x460 put_device+0x20/0x30 pmu_dev_alloc+0x152/0x400 perf_pmu_register+0x96b/0xee0 ... kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) unreferenced object 0xffff888014759000 (size 2048): comm "modprobe", pid 441, jiffies 4294931444 (age 38.332s) backtrace: [<0000000005aed3b4>] kmalloc_trace+0x27/0x110 [<000000006b38f9b8>] pmu_dev_alloc+0x50/0x400 [<00000000735f17be>] perf_pmu_register+0x96b/0xee0 [<00000000e38477f1>] 0xffffffffc0ad8603 [<000000004e162216>] do_one_initcall+0xd0/0x4e0 ... Fixes: abe43400579d ("perf: Sysfs enumeration") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221111103653.91058-1-chenzhongjin@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-07PM: hibernate: Fix mistake in kerneldoc commentxiongxin
[ Upstream commit 6e5d7300cbe7c3541bc31f16db3e9266e6027b4b ] The actual maximum image size formula in hibernate_preallocate_memory() is as follows: max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE); but the one in the kerneldoc comment of the function is different and incorrect. Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers") Signed-off-by: xiongxin <xiongxin@kylinos.cn> [ rjw: Subject and changelog rewrite ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08proc: proc_skip_spaces() shouldn't think it is working on C stringsLinus Torvalds
commit bce9332220bd677d83b19d21502776ad555a0e73 upstream. proc_skip_spaces() seems to think it is working on C strings, and ends up being just a wrapper around skip_spaces() with a really odd calling convention. Instead of basing it on skip_spaces(), it should have looked more like proc_skip_char(), which really is the exact same function (except it skips a particular character, rather than whitespace). So use that as inspiration, odd coding and all. Now the calling convention actually makes sense and works for the intended purpose. Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08proc: avoid integer type confusion in get_proc_longLinus Torvalds
commit e6cfaf34be9fcd1a8285a294e18986bfc41a409c upstream. proc_get_long() is passed a size_t, but then assigns it to an 'int' variable for the length. Let's not do that, even if our IO paths are limited to MAX_RW_COUNT (exactly because of these kinds of type errors). So do the proper test in the rigth type. Reported-by: Kyle Zeng <zengyhkyle@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25ring_buffer: Do not deactivate non-existant pagesDaniil Tatianin
commit 56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd upstream. rb_head_page_deactivate() expects cpu_buffer to contain a valid list of ->pages, so verify that the list is actually present before calling it. Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru Cc: stable@vger.kernel.org Fixes: 77ae365eca895 ("ring-buffer: make lockless") Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25ftrace: Optimize the allocation for mcount entriesWang Wensheng
commit bcea02b096333dc74af987cb9685a4dbdd820840 upstream. If we can't allocate this size, try something smaller with half of the size. Its order should be decreased by one instead of divided by two. Link: https://lkml.kernel.org/r/20221109094434.84046-3-wangwensheng4@huawei.com Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: stable@vger.kernel.org Fixes: a79008755497d ("ftrace: Allocate the mcount record pages as groups") Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25ftrace: Fix the possible incorrect kernel messageWang Wensheng
commit 08948caebe93482db1adfd2154eba124f66d161d upstream. If the number of mcount entries is an integer multiple of ENTRIES_PER_PAGE, the page count showing on the console would be wrong. Link: https://lkml.kernel.org/r/20221109094434.84046-2-wangwensheng4@huawei.com Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: stable@vger.kernel.org Fixes: 5821e1b74f0d0 ("function tracing: fix wrong pos computing when read buffer has been fulfilled") Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26gcov: support GCC 12.1 and newer compilersMartin Liska
commit 977ef30a7d888eeb52fb6908f99080f33e5309a8 upstream. Starting with GCC 12.1, the created .gcda format can't be read by gcov tool. There are 2 significant changes to the .gcda file format that need to be supported: a) [gcov: Use system IO buffering] (23eb66d1d46a34cb28c4acbdf8a1deb80a7c5a05) changed that all sizes in the format are in bytes and not in words (4B) b) [gcov: make profile merging smarter] (72e0c742bd01f8e7e6dcca64042b9ad7e75979de) add a new checksum to the file header. Tested with GCC 7.5, 10.4, 12.2 and the current master. Link: https://lkml.kernel.org/r/624bda92-f307-30e9-9aaa-8cc678b2dfb2@suse.cz Signed-off-by: Martin Liska <mliska@suse.cz> Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26ring-buffer: Fix race between reset page and reading pageSteven Rostedt (Google)
commit a0fcaaed0c46cf9399d3a2d6e0c87ddb3df0e044 upstream. The ring buffer is broken up into sub buffers (currently of page size). Each sub buffer has a pointer to its "tail" (the last event written to the sub buffer). When a new event is requested, the tail is locally incremented to cover the size of the new event. This is done in a way that there is no need for locking. If the tail goes past the end of the sub buffer, the process of moving to the next sub buffer takes place. After setting the current sub buffer to the next one, the previous one that had the tail go passed the end of the sub buffer needs to be reset back to the original tail location (before the new event was requested) and the rest of the sub buffer needs to be "padded". The race happens when a reader takes control of the sub buffer. As readers do a "swap" of sub buffers from the ring buffer to get exclusive access to the sub buffer, it replaces the "head" sub buffer with an empty sub buffer that goes back into the writable portion of the ring buffer. This swap can happen as soon as the writer moves to the next sub buffer and before it updates the last sub buffer with padding. Because the sub buffer can be released to the reader while the writer is still updating the padding, it is possible for the reader to see the event that goes past the end of the sub buffer. This can cause obvious issues. To fix this, add a few memory barriers so that the reader definitely sees the updates to the sub buffer, and also waits until the writer has put back the "tail" of the sub buffer back to the last event that was written on it. To be paranoid, it will only spin for 1 second, otherwise it will warn and shutdown the ring buffer code. 1 second should be enough as the writer does have preemption disabled. If the writer doesn't move within 1 second (with preemption disabled) something is horribly wrong. No interrupt should last 1 second! Link: https://lore.kernel.org/all/20220830120854.7545-1-jiazi.li@transsion.com/ Link: https://bugzilla.kernel.org/show_bug.cgi?id=216369 Link: https://lkml.kernel.org/r/20220929104909.0650a36c@gandalf.local.home Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: c7b0930857e22 ("ring-buffer: prevent adding write in discarded area") Reported-by: Jiazi.Li <jiazi.li@transsion.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26ring-buffer: Check pending waiters when doing wake ups as wellSteven Rostedt (Google)
commit ec0bbc5ec5664dcee344f79373852117dc672c86 upstream. The wake up waiters only checks the "wakeup_full" variable and not the "full_waiters_pending". The full_waiters_pending is set when a waiter is added to the wait queue. The wakeup_full is only set when an event is triggered, and it clears the full_waiters_pending to avoid multiple calls to irq_work_queue(). The irq_work callback really needs to check both wakeup_full as well as full_waiters_pending such that this code can be used to wake up waiters when a file is closed that represents the ring buffer and the waiters need to be woken up. Link: https://lkml.kernel.org/r/20220927231824.209460321@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26ring-buffer: Allow splice to read previous partially read pagesSteven Rostedt (Google)
commit fa8f4a89736b654125fb254b0db753ac68a5fced upstream. If a page is partially read, and then the splice system call is run against the ring buffer, it will always fail to read, no matter how much is in the ring buffer. That's because the code path for a partial read of the page does will fail if the "full" flag is set. The splice system call wants full pages, so if the read of the ring buffer is not yet full, it should return zero, and the splice will block. But if a previous read was done, where the beginning has been consumed, it should still be given to the splice caller if the rest of the page has been written to. This caused the splice command to never consume data in this scenario, and let the ring buffer just fill up and lose events. Link: https://lkml.kernel.org/r/20220927144317.46be6b80@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 8789a9e7df6bf ("ring-buffer: read page interface") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05kprobes: don't call disarm_kprobe() for disabled kprobesKuniyuki Iwashima
commit 9c80e79906b4ca440d09e7f116609262bb747909 upstream. The assumption in __disable_kprobe() is wrong, and it could try to disarm an already disarmed kprobe and fire the WARN_ONCE() below. [0] We can easily reproduce this issue. 1. Write 0 to /sys/kernel/debug/kprobes/enabled. # echo 0 > /sys/kernel/debug/kprobes/enabled 2. Run execsnoop. At this time, one kprobe is disabled. # /usr/share/bcc/tools/execsnoop & [1] 2460 PCOMM PID PPID RET ARGS # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE] 3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes kprobes_all_disarmed to false but does not arm the disabled kprobe. # echo 1 > /sys/kernel/debug/kprobes/enabled # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE] 4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace(). # fg /usr/share/bcc/tools/execsnoop ^C Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses some cleanups and leaves the aggregated kprobe in the hash table. Then, __unregister_trace_kprobe() initialises tk->rp.kp.list and creates an infinite loop like this. aggregated kprobe.list -> kprobe.list -. ^ | '.__.' In this situation, these commands fall into the infinite loop and result in RCU stall or soft lockup. cat /sys/kernel/debug/kprobes/list : show_kprobe_addr() enters into the infinite loop with RCU. /usr/share/bcc/tools/execsnoop : warn_kprobe_rereg() holds kprobe_mutex, and __get_valid_kprobe() is stuck in the loop. To avoid the issue, make sure we don't call disarm_kprobe() for disabled kprobes. [0] Failed to disarm kprobe-ftrace at __x64_sys_execve+0x0/0x40 (error -2) WARNING: CPU: 6 PID: 2460 at kernel/kprobes.c:1130 __disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Modules linked in: ena CPU: 6 PID: 2460 Comm: execsnoop Not tainted 5.19.0+ #28 Hardware name: Amazon EC2 c5.2xlarge/, BIOS 1.0 10/16/2017 RIP: 0010:__disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Code: 24 8b 02 eb c1 80 3d c4 83 f2 01 00 75 d4 48 8b 75 00 89 c2 48 c7 c7 90 fa 0f 92 89 04 24 c6 05 ab 83 01 e8 e4 94 f0 ff <0f> 0b 8b 04 24 eb b1 89 c6 48 c7 c7 60 fa 0f 92 89 04 24 e8 cc 94 RSP: 0018:ffff9e6ec154bd98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffff930f7b00 RCX: 0000000000000001 RDX: 0000000080000001 RSI: ffffffff921461c5 RDI: 00000000ffffffff RBP: ffff89c504286da8 R08: 0000000000000000 R09: c0000000fffeffff R10: 0000000000000000 R11: ffff9e6ec154bc28 R12: ffff89c502394e40 R13: ffff89c502394c00 R14: ffff9e6ec154bc00 R15: 0000000000000000 FS: 00007fe800398740(0000) GS:ffff89c812d80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00057f010 CR3: 0000000103b54006 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> __disable_kprobe (kernel/kprobes.c:1716) disable_kprobe (kernel/kprobes.c:2392) __disable_trace_kprobe (kernel/trace/trace_kprobe.c:340) disable_trace_kprobe (kernel/trace/trace_kprobe.c:429) perf_trace_event_unreg.isra.2 (./include/linux/tracepoint.h:93 kernel/trace/trace_event_perf.c:168) perf_kprobe_destroy (kernel/trace/trace_event_perf.c:295) _free_event (kernel/events/core.c:4971) perf_event_release_kernel (kernel/events/core.c:5176) perf_release (kernel/events/core.c:5186) __fput (fs/file_table.c:321) task_work_run (./include/linux/sched.h:2056 (discriminator 1) kernel/task_work.c:179 (discriminator 1)) exit_to_user_mode_prepare (./include/linux/resume_user_mode.h:49 kernel/entry/common.c:169 kernel/entry/common.c:201) syscall_exit_to_user_mode (./arch/x86/include/asm/jump_label.h:55 ./arch/x86/include/asm/nospec-branch.h:384 ./arch/x86/include/asm/entry-common.h:94 kernel/entry/common.c:133 kernel/entry/common.c:296) do_syscall_64 (arch/x86/entry/common.c:87) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) RIP: 0033:0x7fe7ff210654 Code: 15 79 89 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb be 0f 1f 00 8b 05 9a cd 20 00 48 63 ff 85 c0 75 11 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3a f3 c3 48 83 ec 18 48 89 7c 24 08 e8 34 fc RSP: 002b:00007ffdbd1d3538 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007fe7ff210654 RDX: 0000000000000000 RSI: 0000000000002401 RDI: 0000000000000008 RBP: 0000000000000000 R08: 94ae31d6fda838a4 R0900007fe8001c9d30 R10: 00007ffdbd1d34b0 R11: 0000000000000246 R12: 00007ffdbd1d3600 R13: 0000000000000000 R14: fffffffffffffffc R15: 00007ffdbd1d3560 </TASK> Link: https://lkml.kernel.org/r/20220813020509.90805-1-kuniyu@amazon.com Fixes: 69d54b916d83 ("kprobes: makes kprobes/enabled works correctly for optimized kprobes.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reported-by: Ayushman Dutta <ayudutta@amazon.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Kuniyuki Iwashima <kuniyu@amazon.com> Cc: Kuniyuki Iwashima <kuni1840@gmail.com> Cc: Ayushman Dutta <ayudutta@amazon.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is deadYang Jihong
commit c3b0f72e805f0801f05fa2aa52011c4bfc694c44 upstream. ftrace_startup does not remove ops from ftrace_ops_list when ftrace_startup_enable fails: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&ftrace_ops_list, ops) ... ... ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1 ... return 0 // ops is in the ftrace_ops_list. When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything: unregister_ftrace_function ftrace_shutdown if (unlikely(ftrace_disabled)) return -ENODEV; // return here, __unregister_ftrace_function is not executed, // as a result, ops is still in the ftrace_ops_list __unregister_ftrace_function ... If ops is dynamically allocated, it will be free later, in this case, is_ftrace_trampoline accesses NULL pointer: is_ftrace_trampoline ftrace_ops_trampoline do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL! Syzkaller reports as follows: [ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b [ 1203.508039] #PF: supervisor read access in kernel mode [ 1203.508798] #PF: error_code(0x0000) - not-present page [ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0 [ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI [ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8 [ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0 [ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00 [ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246 [ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866 [ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b [ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07 [ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399 [ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008 [ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 [ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0 [ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Therefore, when ftrace_startup_enable fails, we need to rollback registration process and remove ops from ftrace_ops_list. Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25bpf: fix overflow in prog accountingDaniel Borkmann
commit 5ccb071e97fbd9ffe623a0d3977cc6d013bee93c upstream. Commit aaac3ba95e4c ("bpf: charge user for creation of BPF maps and programs") made a wrong assumption of charging against prog->pages. Unlike map->pages, prog->pages are still subject to change when we need to expand the program through bpf_prog_realloc(). This can for example happen during verification stage when we need to expand and rewrite parts of the program. Should the required space cross a page boundary, then prog->pages is not the same anymore as its original value that we used to bpf_prog_charge_memlock() on. Thus, we'll hit a wrap-around during bpf_prog_uncharge_memlock() when prog is freed eventually. I noticed this that despite having unlimited memlock, programs suddenly refused to load with EPERM error due to insufficient memlock. There are two ways to fix this issue. One would be to add a cached variable to struct bpf_prog that takes a snapshot of prog->pages at the time of charging. The other approach is to also account for resizes. I chose to go with the latter for a couple of reasons: i) We want accounting rather to be more accurate instead of further fooling limits, ii) adding yet another page counter on struct bpf_prog would also be a waste just for this purpose. We also do want to charge as early as possible to avoid going into the verifier just to find out later on that we crossed limits. The only place that needs to be fixed is bpf_prog_realloc(), since only here we expand the program, so we try to account for the needed delta and should we fail, call-sites check for outcome anyway. On cBPF to eBPF migrations, we don't grab a reference to the user as they are charged differently. With that in place, my test case worked fine. Fixes: aaac3ba95e4c ("bpf: charge user for creation of BPF maps and programs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> [Quentin: backport to 4.9: Adjust context in bpf.h ] Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29bpf: Make sure mac_header was set before using itEric Dumazet
commit 0326195f523a549e0a9d7fd44c70b26fd7265090 upstream. Classic BPF has a way to load bytes starting from the mac header. Some skbs do not have a mac header, and skb_mac_header() in this case is returning a pointer that 65535 bytes after skb->head. Existing range check in bpf_internal_load_pointer_neg_helper() was properly kicking and no illegal access was happening. New sanity check in skb_mac_header() is firing, so we need to avoid it. WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 skb_mac_header include/linux/skbuff.h:2785 [inline] WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74 Modules linked in: CPU: 1 PID: 28990 Comm: syz-executor.0 Not tainted 5.19.0-rc4-syzkaller-00865-g4874fb9484be #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 RIP: 0010:skb_mac_header include/linux/skbuff.h:2785 [inline] RIP: 0010:bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74 Code: ff ff 45 31 f6 e9 5a ff ff ff e8 aa 27 40 00 e9 3b ff ff ff e8 90 27 40 00 e9 df fe ff ff e8 86 27 40 00 eb 9e e8 2f 2c f3 ff <0f> 0b eb b1 e8 96 27 40 00 e9 79 fe ff ff 90 41 57 41 56 41 55 41 RSP: 0018:ffffc9000309f668 EFLAGS: 00010216 RAX: 0000000000000118 RBX: ffffffffffeff00c RCX: ffffc9000e417000 RDX: 0000000000040000 RSI: ffffffff81873f21 RDI: 0000000000000003 RBP: ffff8880842878c0 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000001 R12: 0000000000000004 R13: ffff88803ac56c00 R14: 000000000000ffff R15: dffffc0000000000 FS: 00007f5c88a16700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdaa9f6c058 CR3: 000000003a82c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ____bpf_skb_load_helper_32 net/core/filter.c:276 [inline] bpf_skb_load_helper_32+0x191/0x220 net/core/filter.c:264 Fixes: f9aefd6b2aa3 ("net: warn if mac header was not set") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220707123900.945305-1-edumazet@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()Peter Zijlstra
[ Upstream commit 68e3c69803dada336893640110cb87221bb01dcf ] Yang Jihing reported a race between perf_event_set_output() and perf_mmap_close(): CPU1 CPU2 perf_mmap_close(e2) if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0 detach_rest = true ioctl(e1, IOC_SET_OUTPUT, e2) perf_event_set_output(e1, e2) ... list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry) ring_buffer_attach(e, NULL); // e1 isn't yet added and // therefore not detached ring_buffer_attach(e1, e2->rb) list_add_rcu(&e1->rb_entry, &e2->rb->event_list) After this; e1 is attached to an unmapped rb and a subsequent perf_mmap() will loop forever more: again: mutex_lock(&e->mmap_mutex); if (event->rb) { ... if (!atomic_inc_not_zero(&e->rb->mmap_count)) { ... mutex_unlock(&e->mmap_mutex); goto again; } } The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach in perf_event_set_output() holds e1->mmap_mutex. As such there is no serialization to avoid this race. Change perf_event_set_output() to take both e1->mmap_mutex and e2->mmap_mutex to alleviate that problem. Additionally, have the loop in perf_mmap() detach the rb directly, this avoids having to wait for the concurrent perf_mmap_close() to get around to doing it to make progress. Fixes: 9bb5d40cd93c ("perf: Fix mmap() accounting hole") Reported-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yang Jihong <yangjihong1@huawei.com> Link: https://lkml.kernel.org/r/YsQ3jm2GR38SW7uD@worktop.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29security,selinux,smack: kill security_task_wait hookStephen Smalley
commit 3a2f5a59a695a73e0cde9a61e0feae5fa730e936 upstream. As reported by yangshukui, a permission denial from security_task_wait() can lead to a soft lockup in zap_pid_ns_processes() since it only expects sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can in general lead to zombies; in the absence of some way to automatically reparent a child process upon a denial, the hook is not useful. Remove the security hook and its implementations in SELinux and Smack. Smack already removed its check from its hook. Reported-by: yangshukui <yangshukui@huawei.com> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Alexander Grund <theflamefire89@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21signal handling: don't use BUG_ON() for debuggingLinus Torvalds
[ Upstream commit a382f8fee42ca10c9bfce0d2352d4153f931f5dc ] These are indeed "should not happen" situations, but it turns out recent changes made the 'task_is_stopped_or_trace()' case trigger (fix for that exists, is pending more testing), and the BUG_ON() makes it unnecessarily hard to actually debug for no good reason. It's been that way for a long time, but let's make it clear: BUG_ON() is not good for debugging, and should never be used in situations where you could just say "this shouldn't happen, but we can continue". Use WARN_ON_ONCE() instead to make sure it gets logged, and then just continue running. Instead of making the system basically unusuable because you crashed the machine while potentially holding some very core locks (eg this function is commonly called while holding 'tasklist_lock' for writing). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-02kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]Naveen N. Rao
commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream. Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against. Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers. [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1 [akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25timekeeping: Add raw clock fallback for random_get_entropy()Jason A. Donenfeld
commit 1366992e16bddd5e2d9a561687f367f9f802e2e4 upstream. The addition of random_get_entropy_fallback() provides access to whichever time source has the highest frequency, which is useful for gathering entropy on platforms without available cycle counters. It's not necessarily as good as being able to quickly access a cycle counter that the CPU has, but it's still something, even when it falls back to being jiffies-based. In the event that a given arch does not define get_cycles(), falling back to the get_cycles() default implementation that returns 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. Finally, since random_get_entropy_fallback() is used during extremely early boot when randomizing freelists in mm_init(), it can be called before timekeeping has been initialized. In that case there really is nothing we can do; jiffies hasn't even started ticking yet. So just give up and return 0. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: clear fast pool, crng, and batches in cpuhp bring upJason A. Donenfeld
commit 3191dd5a1179ef0fad5a050a1702ae98b6251e8f upstream. For the irq randomness fast pool, rather than having to use expensive atomics, which were visibly the most expensive thing in the entire irq handler, simply take care of the extreme edge case of resetting count to zero in the cpuhp online handler, just after workqueues have been reenabled. This simplifies the code a bit and lets us use vanilla variables rather than atomics, and performance should be improved. As well, very early on when the CPU comes up, while interrupts are still disabled, we clear out the per-cpu crng and its batches, so that it always starts with fresh randomness. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Sultan Alsawaf <sultan@kerneltoast.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25workqueue: make workqueue available early during bootTejun Heo
commit 3347fa0928210d96aaa2bd6cd5a8391d5e630873 upstream. Workqueue is currently initialized in an early init call; however, there are cases where early boot code has to be split and reordered to come after workqueue initialization or the same code path which makes use of workqueues is used both before workqueue initailization and after. The latter cases have to gate workqueue usages with keventd_up() tests, which is nasty and easy to get wrong. Workqueue usages have become widespread and it'd be a lot more convenient if it can be used very early from boot. This patch splits workqueue initialization into two steps. workqueue_init_early() which sets up the basic data structures so that workqueues can be created and work items queued, and workqueue_init() which actually brings up workqueues online and starts executing queued work items. The former step can be done very early during boot once memory allocation, cpumasks and idr are initialized. The latter right after kthreads become available. This allows work item queueing and canceling from very early boot which is what most of these use cases want. * As systemd_wq being initialized doesn't indicate that workqueue is fully online anymore, update keventd_up() to test wq_online instead. The follow-up patches will get rid of all its usages and the function itself. * Flushing doesn't make sense before workqueue is fully initialized. The flush functions trigger WARN and return immediately before fully online. * Work items are never in-flight before fully online. Canceling can always succeed by skipping the flush step. * Some code paths can no longer assume to be called with irq enabled as irq is disabled during early boot. Use irqsave/restore operations instead. v2: Watchdog init, which requires timer to be running, moved from workqueue_init_early() to workqueue_init(). Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/CA+55aFx0vPuMuxn00rBSM192n-Du5uxy+4AvKa0SBSOVJeuCGg@mail.gmail.com Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25random: remove unused irq_flags argument from add_interrupt_randomness()Sebastian Andrzej Siewior
commit 703f7066f40599c290babdb79dd61319264987e9 upstream. Since commit ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter") the irq_flags argument is no longer used. Remove unused irq_flags. Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Liu <wei.liu@kernel.org> Cc: linux-hyperv@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14tracing: Avoid adding tracer option before update_tracer_optionsMark-PK Tsai
[ Upstream commit ef9188bcc6ca1d8a2ad83e826b548e6820721061 ] To prepare for support asynchronous tracer_init_tracefs initcall, avoid calling create_trace_option_files before __update_tracer_options. Otherwise, create_trace_option_files will show warning because some tracers in trace_types list are already in tr->topts. For example, hwlat_tracer call register_tracer in late_initcall, and global_trace.dir is already created in tracing_init_dentry, hwlat_tracer will be put into tr->topts. Then if the __update_tracer_options is executed after hwlat_tracer registered, create_trace_option_files find that hwlat_tracer is already in tr->topts. Link: https://lkml.kernel.org/r/20220426122407.17042-2-mark-pk.tsai@mediatek.com Link: https://lore.kernel.org/lkml/20220322133339.GA32582@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14ptrace: Reimplement PTRACE_KILL by always sending SIGKILLEric W. Biederman
commit 6a2d90ba027adba528509ffa27097cffd3879257 upstream. The current implementation of PTRACE_KILL is buggy and has been for many years as it assumes it's target has stopped in ptrace_stop. At a quick skim it looks like this assumption has existed since ptrace support was added in linux v1.0. While PTRACE_KILL has been deprecated we can not remove it as a quick search with google code search reveals many existing programs calling it. When the ptracee is not stopped at ptrace_stop some fields would be set that are ignored except in ptrace_stop. Making the userspace visible behavior of PTRACE_KILL a noop in those case. As the usual rules are not obeyed it is not clear what the consequences are of calling PTRACE_KILL on a running process. Presumably userspace does not do this as it achieves nothing. Replace the implementation of PTRACE_KILL with a simple send_sig_info(SIGKILL) followed by a return 0. This changes the observable user space behavior only in that PTRACE_KILL on a process not stopped in ptrace_stop will also kill it. As that has always been the intent of the code this seems like a reasonable change. Cc: stable@vger.kernel.org Reported-by: Al Viro <viro@zeniv.linux.org.uk> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-7-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25perf: Fix sys_perf_event_open() race against selfPeter Zijlstra
commit 3ac6487e584a1eb54071dbe1212e05b884136704 upstream. Norbert reported that it's possible to race sys_perf_event_open() such that the looser ends up in another context from the group leader, triggering many WARNs. The move_group case checks for races against itself, but the !move_group case doesn't, seemingly relying on the previous group_leader->ctx == ctx check. However, that check is racy due to not holding any locks at that time. Therefore, re-check the result after acquiring locks and bailing if they no longer match. Additionally, clarify the not_move_group case from the move_group-vs-move_group race. Fixes: f63a8daa5812 ("perf: Fix event->ctx locking") Reported-by: Norbert Slusarek <nslusarek@gmx.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20smp: Fix offline cpu check in flush_smp_call_function_queue()Nadav Amit
commit 9e949a3886356fe9112c6f6f34a6e23d1d35407f upstream. The check in flush_smp_call_function_queue() for callbacks that are sent to offline CPUs currently checks whether the queue is empty. However, flush_smp_call_function_queue() has just deleted all the callbacks from the queue and moved all the entries into a local list. This checks would only be positive if some callbacks were added in the short time after llist_del_all() was called. This does not seem to be the intention of this check. Change the check to look at the local list to which the entries were moved instead of the queue from which all the callbacks were just removed. Fixes: 8d056c48e4862 ("CPU hotplug, smp: flush any pending IPI callbacks before CPU offline") Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220319072015.1495036-1-namit@vmware.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20printk: fix return value of printk.devkmsg __setup handlerRandy Dunlap
[ Upstream commit b665eae7a788c5e2bc10f9ac3c0137aa0ad1fc97 ] If an invalid option value is used with "printk.devkmsg=<value>", it is silently ignored. If a valid option value is used, it is honored but the wrong return value (0) is used, indicating that the command line option had an error and was not handled. This string is not added to init's environment strings due to init/main.c::unknown_bootoption() checking for a '.' in the boot option string and then considering that string to be an "Unused module parameter". Print a warning message if a bad option string is used. Always return 1 from the __setup handler to indicate that the command line option has been handled. Fixes: 750afe7babd1 ("printk: add kernel parameter to control writes to /dev/kmsg") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Cc: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: John Ogness <john.ogness@linutronix.de> Reviewed-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220228220556.23484-1-rdunlap@infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20perf/core: Fix address filter parser for multiple filtersAdrian Hunter
[ Upstream commit d680ff24e9e14444c63945b43a37ede7cd6958f9 ] Reset appropriate variables in the parser loop between parsing separate filters, so that they do not interfere with parsing the next filter. Fixes: 375637bc524952 ("perf/core: Introduce address range filtering") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220131072453.2839535-4-adrian.hunter@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20sched/debug: Remove mpol_get/put and task_lock/unlock from sched_show_numaBharata B Rao
[ Upstream commit 28c988c3ec29db74a1dda631b18785958d57df4f ] The older format of /proc/pid/sched printed home node info which required the mempolicy and task lock around mpol_get(). However the format has changed since then and there is no need for sched_show_numa() any more to have mempolicy argument, asssociated mpol_get/put and task_lock/unlock. Remove them. Fixes: 397f2378f1361 ("sched/numa: Fix numa balancing stats in /proc/pid/sched") Signed-off-by: Bharata B Rao <bharata@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Link: https://lore.kernel.org/r/20220118050515.2973-1-bharata@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20PM: suspend: fix return value of __setup handlerRandy Dunlap
[ Upstream commit 7a64ca17e4dd50d5f910769167f3553902777844 ] If an invalid option is given for "test_suspend=<option>", the entire string is added to init's environment, so return 1 instead of 0 from the __setup handler. Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5 test_suspend=invalid" and Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 test_suspend=invalid Fixes: 2ce986892faf ("PM / sleep: Enhance test_suspend option with repeat capability") Fixes: 27ddcc6596e5 ("PM / sleep: Add state field to pm_states[] entries") Fixes: a9d7052363a6 ("PM: Separate suspend to RAM functionality from core") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20PM: hibernate: fix __setup handler error handlingRandy Dunlap
[ Upstream commit ba7ffcd4c4da374b0f64666354eeeda7d3827131 ] If an invalid value is used in "resumedelay=<seconds>", it is silently ignored. Add a warning message and then let the __setup handler return 1 to indicate that the kernel command line option has been handled. Fixes: 317cf7e5e85e3 ("PM / hibernate: convert simple_strtoul to kstrtoul") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZEJann Horn
commit ee1fee900537b5d9560e9f937402de5ddc8412f3 upstream. Setting PTRACE_O_SUSPEND_SECCOMP is supposed to be a highly privileged operation because it allows the tracee to completely bypass all seccomp filters on kernels with CONFIG_CHECKPOINT_RESTORE=y. It is only supposed to be settable by a process with global CAP_SYS_ADMIN, and only if that process is not subject to any seccomp filters at all. However, while these permission checks were done on the PTRACE_SETOPTIONS path, they were missing on the PTRACE_SEIZE path, which also sets user-specified ptrace flags. Move the permissions checks out into a helper function and let both ptrace_attach() and ptrace_setoptions() call it. Cc: stable@kernel.org Fixes: 13c4a90119d2 ("seccomp: add ptrace options for suspend/resume") Signed-off-by: Jann Horn <jannh@google.com> Link: https://lkml.kernel.org/r/20220319010838.1386861-1-jannh@google.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16tracing: Ensure trace buffer is at least 4096 bytes largeSven Schnelle
[ Upstream commit 7acf3a127bb7c65ff39099afd78960e77b2ca5de ] Booting the kernel with 'trace_buf_size=1' give a warning at boot during the ftrace selftests: [ 0.892809] Running postponed tracer tests: [ 0.892893] Testing tracer function: [ 0.901899] Callback from call_rcu_tasks_trace() invoked. [ 0.983829] Callback from call_rcu_tasks_rude() invoked. [ 1.072003] .. bad ring buffer .. corrupted trace buffer .. [ 1.091944] Callback from call_rcu_tasks() invoked. [ 1.097695] PASSED [ 1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED! [ 1.353474] ------------[ cut here ]------------ [ 1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0 Therefore enforce a minimum of 4096 bytes to make the selftest pass. Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-11x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation ↵Josh Poimboeuf
reporting commit 44a3918c8245ab10c6c9719dd12e7a8d291980d8 upstream. With unprivileged eBPF enabled, eIBRS (without retpoline) is vulnerable to Spectre v2 BHB-based attacks. When both are enabled, print a warning message and report it in the 'spectre_v2' sysfs vulnerabilities file. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> [fllinden@amazon.com: backported to 4.19] Signed-off-by: Frank van der Linden <fllinden@amazon.com> [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23tracing: Fix tp_printk option related with tp_printk_stop_on_bootJaeSang Yoo
[ Upstream commit 3203ce39ac0b2a57a84382ec184c7d4a0bede175 ] The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is the same as another kernel parameter "tp_printk". If "tp_printk" setup is called before the "tp_printk_stop_on_boot", it will override the latter and keep it from being set. This is similar to other kernel parameter issues, such as: Commit 745a600cf1a6 ("um: console: Ignore console= option") or init/do_mounts.c:45 (setup function of "ro" kernel param) Fix it by checking for a "_" right after the "tp_printk" and if that exists do not process the parameter. Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> [ Fixed up change log and added space after if condition ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-23taskstats: Cleanup the use of task->exit_codeEric W. Biederman
commit 1b5a42d9c85f0e731f01c8d1129001fd8531a8a0 upstream. In the function bacct_add_task the code reading task->exit_code was introduced in commit f3cef7a99469 ("[PATCH] csa: basic accounting over taskstats"), and it is not entirely clear what the taskstats interface is trying to return as only returning the exit_code of the first task in a process doesn't make a lot of sense. As best as I can figure the intent is to return task->exit_code after a task exits. The field is returned with per task fields, so the exit_code of the entire process is not wanted. Only the value of the first task is returned so this is not a useful way to get the per task ptrace stop code. The ordinary case of returning this value is returning after a task exits, which also precludes use for getting a ptrace value. It is common to for the first task of a process to also be the last task of a process so this field may have done something reasonable by accident in testing. Make ac_exitcode a reliable per task value by always returning it for every exited task. Setting ac_exitcode in a sensible mannter makes it possible to continue to provide this value going forward. Cc: Balbir Singh <bsingharora@gmail.com> Fixes: f3cef7a99469 ("[PATCH] csa: basic accounting over taskstats") Link: https://lkml.kernel.org/r/20220103213312.9144-5-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> [sudip: adjust context] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16bpf: Add kconfig knob for disabling unpriv bpf by defaultDaniel Borkmann
commit 08389d888287c3823f80b0216766b71e17f0aba5 upstream. Add a kconfig knob which allows for unprivileged bpf to be disabled by default. If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2. This still allows a transition of 2 -> {0,1} through an admin. Similarly, this also still keeps 1 -> {1} behavior intact, so that once set to permanently disabled, it cannot be undone aside from a reboot. We've also added extra2 with max of 2 for the procfs handler, so that an admin still has a chance to toggle between 0 <-> 2. Either way, as an additional alternative, applications can make use of CAP_BPF that we added a while ago. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net [fllinden@amazon.com: backported to 4.9] Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-11cgroup-v1: Require capabilities to set release_agentEric W. Biederman
commit 24f6008564183aa120d07c03d9289519c2fe02af upstream. The cgroup release_agent is called with call_usermodehelper. The function call_usermodehelper starts the release_agent with a full set fo capabilities. Therefore require capabilities when setting the release_agaent. Reported-by: Tabitha Sable <tabitha.c.sable@gmail.com> Tested-by: Tabitha Sable <tabitha.c.sable@gmail.com> Fixes: 81a6a5cdd2c5 ("Task Control Groups: automatic userspace notification of idle cgroups") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Tejun Heo <tj@kernel.org> [mkoutny: Adjust for pre-fs_context, duplicate mount/remount check, drop log messages.] Acked-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08PM: wakeup: simplify the output logic of pm_show_wakelocks()Greg Kroah-Hartman
commit c9d967b2ce40d71e968eb839f36c936b8a9cf1ea upstream. The buffer handling in pm_show_wakelocks() is tricky, and hopefully correct. Ensure it really is correct by using sysfs_emit_at() which handles all of the tricky string handling logic in a PAGE_SIZE buffer for us automatically as this is a sysfs file being read from. Reviewed-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11tracing: Tag trace_percpu_buffer as a percpu pointerNaveen N. Rao
commit f28439db470cca8b6b082239314e9fd10bd39034 upstream. Tag trace_percpu_buffer as a percpu pointer to resolve warnings reported by sparse: /linux/kernel/trace/trace.c:3218:46: warning: incorrect type in initializer (different address spaces) /linux/kernel/trace/trace.c:3218:46: expected void const [noderef] __percpu *__vpp_verify /linux/kernel/trace/trace.c:3218:46: got struct trace_buffer_struct * /linux/kernel/trace/trace.c:3234:9: warning: incorrect type in initializer (different address spaces) /linux/kernel/trace/trace.c:3234:9: expected void const [noderef] __percpu *__vpp_verify /linux/kernel/trace/trace.c:3234:9: got int * Link: https://lkml.kernel.org/r/ebabd3f23101d89cb75671b68b6f819f5edc830b.1640255304.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Fixes: 07d777fe8c398 ("tracing: Add percpu buffers for trace_printk()") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11tracing: Fix check for trace_percpu_buffer validity in get_trace_buf()Naveen N. Rao
commit 823e670f7ed616d0ce993075c8afe0217885f79d upstream. With the new osnoise tracer, we are seeing the below splat: Kernel attempted to read user page (c7d880000) - exploit attempt? (uid: 0) BUG: Unable to handle kernel data access on read at 0xc7d880000 Faulting instruction address: 0xc0000000002ffa10 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries ... NIP [c0000000002ffa10] __trace_array_vprintk.part.0+0x70/0x2f0 LR [c0000000002ff9fc] __trace_array_vprintk.part.0+0x5c/0x2f0 Call Trace: [c0000008bdd73b80] [c0000000001c49cc] put_prev_task_fair+0x3c/0x60 (unreliable) [c0000008bdd73be0] [c000000000301430] trace_array_printk_buf+0x70/0x90 [c0000008bdd73c00] [c0000000003178b0] trace_sched_switch_callback+0x250/0x290 [c0000008bdd73c90] [c000000000e70d60] __schedule+0x410/0x710 [c0000008bdd73d40] [c000000000e710c0] schedule+0x60/0x130 [c0000008bdd73d70] [c000000000030614] interrupt_exit_user_prepare_main+0x264/0x270 [c0000008bdd73de0] [c000000000030a70] syscall_exit_prepare+0x150/0x180 [c0000008bdd73e10] [c00000000000c174] system_call_vectored_common+0xf4/0x278 osnoise tracer on ppc64le is triggering osnoise_taint() for negative duration in get_int_safe_duration() called from trace_sched_switch_callback()->thread_exit(). The problem though is that the check for a valid trace_percpu_buffer is incorrect in get_trace_buf(). The check is being done after calculating the pointer for the current cpu, rather than on the main percpu pointer. Fix the check to be against trace_percpu_buffer. Link: https://lkml.kernel.org/r/a920e4272e0b0635cf20c444707cbce1b2c8973d.1640255304.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: e2ace001176dc9 ("tracing: Choose static tp_printk buffer by explicit nesting count") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22timekeeping: Really make sure wall_to_monotonic isn't positiveYu Liao
commit 4e8c11b6b3f0b6a283e898344f154641eda94266 upstream. Even after commit e1d7ba873555 ("time: Always make sure wall_to_monotonic isn't positive") it is still possible to make wall_to_monotonic positive by running the following code: int main(void) { struct timespec time; clock_gettime(CLOCK_MONOTONIC, &time); time.tv_nsec = 0; clock_settime(CLOCK_REALTIME, &time); return 0; } The reason is that the second parameter of timespec64_compare(), ts_delta, may be unnormalized because the delta is calculated with an open coded substraction which causes the comparison of tv_sec to yield the wrong result: wall_to_monotonic = { .tv_sec = -10, .tv_nsec = 900000000 } ts_delta = { .tv_sec = -9, .tv_nsec = -900000000 } That makes timespec64_compare() claim that wall_to_monotonic < ts_delta, but actually the result should be wall_to_monotonic > ts_delta. After normalization, the result of timespec64_compare() is correct because the tv_sec comparison is not longer misleading: wall_to_monotonic = { .tv_sec = -10, .tv_nsec = 900000000 } ts_delta = { .tv_sec = -10, .tv_nsec = 100000000 } Use timespec64_sub() to ensure that ts_delta is normalized, which fixes the issue. Fixes: e1d7ba873555 ("time: Always make sure wall_to_monotonic isn't positive") Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211213135727.1656662-1-liaoyu15@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22tracing: Fix a kmemleak false positive in tracing_mapChen Jun
[ Upstream commit f25667e5980a4333729cac3101e5de1bb851f71a ] Doing the command: echo 'hist:key=common_pid.execname,common_timestamp' > /sys/kernel/debug/tracing/events/xxx/trigger Triggers many kmemleak reports: unreferenced object 0xffff0000c7ea4980 (size 128): comm "bash", pid 338, jiffies 4294912626 (age 9339.324s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000f3469921>] kmem_cache_alloc_trace+0x4c0/0x6f0 [<0000000054ca40c3>] hist_trigger_elt_data_alloc+0x140/0x178 [<00000000633bd154>] tracing_map_init+0x1f8/0x268 [<000000007e814ab9>] event_hist_trigger_func+0xca0/0x1ad0 [<00000000bf8520ed>] trigger_process_regex+0xd4/0x128 [<00000000f549355a>] event_trigger_write+0x7c/0x120 [<00000000b80f898d>] vfs_write+0xc4/0x380 [<00000000823e1055>] ksys_write+0x74/0xf8 [<000000008a9374aa>] __arm64_sys_write+0x24/0x30 [<0000000087124017>] do_el0_svc+0x88/0x1c0 [<00000000efd0dcd1>] el0_svc+0x1c/0x28 [<00000000dbfba9b3>] el0_sync_handler+0x88/0xc0 [<00000000e7399680>] el0_sync+0x148/0x180 unreferenced object 0xffff0000c7ea4980 (size 128): comm "bash", pid 338, jiffies 4294912626 (age 9339.324s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000f3469921>] kmem_cache_alloc_trace+0x4c0/0x6f0 [<0000000054ca40c3>] hist_trigger_elt_data_alloc+0x140/0x178 [<00000000633bd154>] tracing_map_init+0x1f8/0x268 [<000000007e814ab9>] event_hist_trigger_func+0xca0/0x1ad0 [<00000000bf8520ed>] trigger_process_regex+0xd4/0x128 [<00000000f549355a>] event_trigger_write+0x7c/0x120 [<00000000b80f898d>] vfs_write+0xc4/0x380 [<00000000823e1055>] ksys_write+0x74/0xf8 [<000000008a9374aa>] __arm64_sys_write+0x24/0x30 [<0000000087124017>] do_el0_svc+0x88/0x1c0 [<00000000efd0dcd1>] el0_svc+0x1c/0x28 [<00000000dbfba9b3>] el0_sync_handler+0x88/0xc0 [<00000000e7399680>] el0_sync+0x148/0x180 The reason is elts->pages[i] is alloced by get_zeroed_page. and kmemleak will not scan the area alloced by get_zeroed_page. The address stored in elts->pages will be regarded as leaked. That is, the elts->pages[i] will have pointers loaded onto it as well, and without telling kmemleak about it, those pointers will look like memory without a reference. To fix this, call kmemleak_alloc to tell kmemleak to scan elts->pages[i] Link: https://lkml.kernel.org/r/20211124140801.87121-1-chenjun102@huawei.com Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-14wait: add wake_up_pollfree()Eric Biggers
commit 42288cb44c4b5fff7653bc392b583a2b8bd6a8c0 upstream. Several ->poll() implementations are special in that they use a waitqueue whose lifetime is the current task, rather than the struct file as is normally the case. This is okay for blocking polls, since a blocking poll occurs within one task; however, non-blocking polls require another solution. This solution is for the queue to be cleared before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'. However, that has a bug: wake_up_poll() calls __wake_up() with nr_exclusive=1. Therefore, if there are multiple "exclusive" waiters, and the wakeup function for the first one returns a positive value, only that one will be called. That's *not* what's needed for POLLFREE; POLLFREE is special in that it really needs to wake up everyone. Considering the three non-blocking poll systems: - io_uring poll doesn't handle POLLFREE at all, so it is broken anyway. - aio poll is unaffected, since it doesn't support exclusive waits. However, that's fragile, as someone could add this feature later. - epoll doesn't appear to be broken by this, since its wakeup function returns 0 when it sees POLLFREE. But this is fragile. Although there is a workaround (see epoll), it's better to define a function which always sends POLLFREE to all waiters. Add such a function. Also make it verify that the queue really becomes empty after all waiters have been woken up. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08kprobes: Limit max data_size of the kretprobe instancesMasami Hiramatsu
commit 6bbfa44116689469267f1a6e3d233b52114139d2 upstream. The 'kprobe::data_size' is unsigned, thus it can not be negative. But if user sets it enough big number (e.g. (size_t)-8), the result of 'data_size + sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct kretprobe_instance) or zero. In result, the kretprobe_instance are allocated without enough memory, and kretprobe accesses outside of allocated memory. To avoid this issue, introduce a max limitation of the kretprobe::data_size. 4KB per instance should be OK. Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: f47cd9b553aa ("kprobes: kretprobe user entry-handler") Reported-by: zhangyue <zhangyue1@kylinos.cn> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>