syzbot


possible deadlock in static_key_slow_inc (2)

Status: upstream: reported C repro on 2022/12/29 19:42
Reported-by: syzbot+34c26c392ce9937f8ea7@syzkaller.appspotmail.com
First crash: 540d, last: 501d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in static_key_slow_inc C done 1908 360d 472d 3/3 fixed on 2023/08/16 18:53
upstream possible deadlock in static_key_slow_inc 5 2490d 2425d 0/27 closed as invalid on 2017/10/31 11:27
linux-4.14 possible deadlock in static_key_slow_inc 1 873d 873d 0/1 auto-closed as invalid on 2022/05/31 03:42
upstream possible deadlock in static_key_slow_inc (3) cgroups C done 6387 331d 379d 23/27 fixed on 2023/09/28 17:51
upstream possible deadlock in static_key_slow_inc (2) cgroups C error 32622 379d 597d 22/27 fixed on 2023/06/08 14:41
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/02/06 18:45 28m bisect fix linux-4.14.y job log (0) log

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
4.14.302-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor113/7954 is trying to acquire lock:
 (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8167d71e>] static_key_slow_inc+0xe/0x20 kernel/jump_label.c:123

but task is already holding lock:
 (tracepoints_mutex){+.+.}, at: [<ffffffff81568d58>] tracepoint_probe_register_prio kernel/tracepoint.c:327 [inline]
 (tracepoints_mutex){+.+.}, at: [<ffffffff81568d58>] tracepoint_probe_register+0x68/0xc0 kernel/tracepoint.c:352

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (tracepoints_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       tracepoint_probe_register_prio kernel/tracepoint.c:327 [inline]
       tracepoint_probe_register+0x68/0xc0 kernel/tracepoint.c:352
       trace_event_reg+0x272/0x330 kernel/trace/trace_events.c:305
       perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
       perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
       perf_trace_init+0x424/0xa30 kernel/trace/trace_event_perf.c:221
       perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8145
       perf_try_init_event+0xdf/0x1f0 kernel/events/core.c:9379
       perf_init_event kernel/events/core.c:9417 [inline]
       perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9677
       perf_event_alloc kernel/events/core.c:10047 [inline]
       SYSC_perf_event_open kernel/events/core.c:10151 [inline]
       SyS_perf_event_open+0x683/0x2530 kernel/events/core.c:10037
       do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x5e/0xd3

-> #4 (event_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       perf_trace_init+0x4f/0xa30 kernel/trace/trace_event_perf.c:216
       perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8145
       perf_try_init_event+0xdf/0x1f0 kernel/events/core.c:9379
       perf_init_event kernel/events/core.c:9417 [inline]
       perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9677
       perf_event_alloc kernel/events/core.c:10047 [inline]
       SYSC_perf_event_open kernel/events/core.c:10151 [inline]
       SyS_perf_event_open+0x683/0x2530 kernel/events/core.c:10037
       do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x5e/0xd3

-> #3 (&cpuctx_mutex/1){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       mutex_lock_double kernel/events/core.c:9873 [inline]
       __perf_event_ctx_lock_double kernel/events/core.c:10017 [inline]
       SYSC_perf_event_open kernel/events/core.c:10282 [inline]
       SyS_perf_event_open+0xd13/0x2530 kernel/events/core.c:10037
       do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x5e/0xd3

-> #2 (&cpuctx_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       perf_event_init_cpu+0xb7/0x170 kernel/events/core.c:11291
       perf_event_init+0x2cc/0x308 kernel/events/core.c:11338
       start_kernel+0x45d/0x763 init/main.c:624
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240

-> #1 (pmus_lock){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       perf_event_init_cpu+0x2c/0x170 kernel/events/core.c:11285
       cpuhp_invoke_callback+0x1e6/0x1a80 kernel/cpu.c:186
       cpuhp_up_callbacks kernel/cpu.c:574 [inline]
       _cpu_up+0x21e/0x520 kernel/cpu.c:1193
       do_cpu_up+0x9a/0x160 kernel/cpu.c:1229
       smp_init+0x197/0x1ac kernel/smp.c:578
       kernel_init_freeable+0x406/0x626 init/main.c:1074
       kernel_init+0xd/0x15d init/main.c:1006
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406

-> #0 (cpu_hotplug_lock.rw_sem){++++}:
       lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
       percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
       percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
       cpus_read_lock+0x39/0xc0 kernel/cpu.c:297
       static_key_slow_inc+0xe/0x20 kernel/jump_label.c:123
       tracepoint_add_func+0x747/0xa40 kernel/tracepoint.c:269
       tracepoint_probe_register_prio kernel/tracepoint.c:331 [inline]
       tracepoint_probe_register+0x8c/0xc0 kernel/tracepoint.c:352
       trace_event_reg+0x272/0x330 kernel/trace/trace_events.c:305
       perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
       perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
       perf_trace_init+0x424/0xa30 kernel/trace/trace_event_perf.c:221
       perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8145
       perf_try_init_event+0xdf/0x1f0 kernel/events/core.c:9379
       perf_init_event kernel/events/core.c:9417 [inline]
       perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9677
       perf_event_alloc kernel/events/core.c:10047 [inline]
       SYSC_perf_event_open kernel/events/core.c:10151 [inline]
       SyS_perf_event_open+0x683/0x2530 kernel/events/core.c:10037
       do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x5e/0xd3

other info that might help us debug this:

Chain exists of:
  cpu_hotplug_lock.rw_sem --> event_mutex --> tracepoints_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tracepoints_mutex);
                               lock(event_mutex);
                               lock(tracepoints_mutex);
  lock(cpu_hotplug_lock.rw_sem);

 *** DEADLOCK ***

4 locks held by syz-executor113/7954:
 #0:  (&pmus_srcu){....}, at: [<ffffffff8163a9d4>] fdput include/linux/file.h:40 [inline]
 #0:  (&pmus_srcu){....}, at: [<ffffffff8163a9d4>] perf_cgroup_connect kernel/events/core.c:849 [inline]
 #0:  (&pmus_srcu){....}, at: [<ffffffff8163a9d4>] perf_event_alloc.part.0+0xc44/0x2640 kernel/events/core.c:9672
 #1:  (&cpuctx_mutex/1){+.+.}, at: [<ffffffff81636ded>] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1241
 #2:  (event_mutex){+.+.}, at: [<ffffffff815b1e4f>] perf_trace_init+0x4f/0xa30 kernel/trace/trace_event_perf.c:216
 #3:  (tracepoints_mutex){+.+.}, at: [<ffffffff81568d58>] tracepoint_probe_register_prio kernel/tracepoint.c:327 [inline]
 #3:  (tracepoints_mutex){+.+.}, at: [<ffffffff81568d58>] tracepoint_probe_register+0x68/0xc0 kernel/tracepoint.c:352

stack backtrace:
CPU: 0 PID: 7954 Comm: syz-executor113 Not tainted 4.14.302-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258
 check_prev_add kernel/locking/lockdep.c:1905 [inline]
 check_prevs_add kernel/locking/lockdep.c:2022 [inline]
 validate_chain kernel/locking/lockdep.c:2464 [inline]
 __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 cpus_read_lock+0x39/0xc0 kernel/cpu.c:297
 static_key_slow_inc+0xe/0x20 kernel/jump_label.c:123
 tracepoint_add_func+0x747/0xa40 kernel/tracepoint.c:269
 tracepoint_probe_register_prio kernel/tracepoint.c:331 [inline]
 tracepoint_probe_register+0x8c/0xc0 kernel/tracepoint.c:352
 trace_event_reg+0x272/0x330 kernel/trace/trace_events.c:305
 perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
 perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
 perf_trace_init+0x424/0xa30 kernel/trace/trace_event_perf.c:221
 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8145
 perf_try_init_event+0xdf/0x1f0 kernel/events/core.c:9379
 perf_init_event kernel/events/core.c:9417 [inline]
 perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9677
 perf_event_alloc kernel/events/core.c:10047 [inline]
 SYSC_perf_event_open kernel/events/core.c:10151 [inline]
 SyS_perf_event_open+0x683/0x2530 kernel/events/core.c:10037
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7ff23b6fc489
RSP: 002b:00007ffeace993b8 EFLAGS: 0000

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/07 18:39 linux-4.14.y c4215ee4771b 1dac8c7a .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in static_key_slow_inc
2022/12/29 19:42 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in static_key_slow_inc
* Struck through repros no longer work on HEAD.