====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-00329-g5d12ed4bea43 #0 Not tainted ------------------------------------------------------ syz-executor.2/19967 is trying to acquire lock: ffff8880b943d998 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x39e/0x1020 kernel/workqueue.c:2360 but task is already holding lock: ffff888028b7aea0 (&sighand->signalfd_wqh){-...}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] ffff888028b7aea0 (&sighand->signalfd_wqh){-...}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sighand->signalfd_wqh){-...}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 signalfd_notify include/linux/signalfd.h:22 [inline] __send_signal_locked+0x951/0x11c0 kernel/signal.c:1168 do_notify_parent+0xeb4/0x1040 kernel/signal.c:2143 exit_notify kernel/exit.c:754 [inline] do_exit+0x1369/0x2c10 kernel/exit.c:898 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&sighand->siglock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x290/0x300 kernel/signal.c:1453 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x176/0x460 kernel/trace/bpf_trace.c:2422 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 include/trace/events/mmap_lock.h:52 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x456/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_lock include/linux/mmap_lock.h:147 [inline] prctl_set_mm_map+0x623/0x7e0 kernel/sys.c:2066 prctl_set_mm+0x6e2/0xa30 kernel/sys.c:2159 __do_sys_prctl+0x136/0x1f70 kernel/sys.c:2592 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (lock#10){+.+.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x97/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:166 [inline] stack_map_get_build_id_offset+0x5df/0x7d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1975 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run3+0x167/0x440 kernel/trace/bpf_trace.c:2421 __bpf_trace_workqueue_queue_work+0x101/0x140 include/trace/events/workqueue.h:23 trace_workqueue_queue_work include/trace/events/workqueue.h:23 [inline] __queue_work+0x627/0x1020 kernel/workqueue.c:2382 queue_work_on+0xf4/0x120 kernel/workqueue.c:2435 bpf_prog_load+0x19bb/0x2660 kernel/bpf/syscall.c:2944 __sys_bpf+0x9b4/0x4b40 kernel/bpf/syscall.c:5660 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5765 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&pool->lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __queue_work+0x39e/0x1020 kernel/workqueue.c:2360 queue_work_on+0xf4/0x120 kernel/workqueue.c:2435 queue_work include/linux/workqueue.h:605 [inline] schedule_work include/linux/workqueue.h:666 [inline] aio_poll_wake+0x1cb/0xcc0 fs/aio.c:1845 __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89 __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:127 signalfd_notify include/linux/signalfd.h:22 [inline] send_sigqueue+0x75c/0x850 kernel/signal.c:2018 posix_timer_event+0xe1/0x130 kernel/time/posix-timers.c:298 cpu_timer_fire kernel/time/posix-cpu-timers.c:605 [inline] cpu_timer_fire+0x156/0x270 kernel/time/posix-cpu-timers.c:583 posix_cpu_timer_set+0x8f7/0x1350 kernel/time/posix-cpu-timers.c:764 do_timer_settime+0x1e8/0x2f0 kernel/time/posix-timers.c:925 __do_sys_timer_settime kernel/time/posix-timers.c:954 [inline] __se_sys_timer_settime kernel/time/posix-timers.c:940 [inline] __x64_sys_timer_settime+0x26a/0x2c0 kernel/time/posix-timers.c:940 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &pool->lock --> &sighand->siglock --> &sighand->signalfd_wqh Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sighand->signalfd_wqh); lock(&sighand->siglock); lock(&sighand->signalfd_wqh); lock(&pool->lock); *** DEADLOCK *** 6 locks held by syz-executor.2/19967: #0: ffff88807bf3f7b8 (&posix_cpu_timers_key){+.+.}-{2:2}, at: __lock_timer+0x211/0x4c0 kernel/time/posix-timers.c:595 #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: posix_cpu_timer_set+0xe1/0x1350 kernel/time/posix-cpu-timers.c:634 #2: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: send_sigqueue+0x10c/0x850 kernel/signal.c:1979 #3: ffff888028b7ae58 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0xc2/0x340 kernel/signal.c:1414 #4: ffff888028b7aea0 (&sighand->signalfd_wqh){-...}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] #4: ffff888028b7aea0 (&sighand->signalfd_wqh){-...}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 #5: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #5: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #5: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: __queue_work+0xf2/0x1020 kernel/workqueue.c:2324 stack backtrace: CPU: 0 PID: 19967 Comm: syz-executor.2 Not tainted 6.9.0-rc5-syzkaller-00329-g5d12ed4bea43 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __queue_work+0x39e/0x1020 kernel/workqueue.c:2360 queue_work_on+0xf4/0x120 kernel/workqueue.c:2435 queue_work include/linux/workqueue.h:605 [inline] schedule_work include/linux/workqueue.h:666 [inline] aio_poll_wake+0x1cb/0xcc0 fs/aio.c:1845 __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89 __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:127 signalfd_notify include/linux/signalfd.h:22 [inline] send_sigqueue+0x75c/0x850 kernel/signal.c:2018 posix_timer_event+0xe1/0x130 kernel/time/posix-timers.c:298 cpu_timer_fire kernel/time/posix-cpu-timers.c:605 [inline] cpu_timer_fire+0x156/0x270 kernel/time/posix-cpu-timers.c:583 posix_cpu_timer_set+0x8f7/0x1350 kernel/time/posix-cpu-timers.c:764 do_timer_settime+0x1e8/0x2f0 kernel/time/posix-timers.c:925 __do_sys_timer_settime kernel/time/posix-timers.c:954 [inline] __se_sys_timer_settime kernel/time/posix-timers.c:940 [inline] __x64_sys_timer_settime+0x26a/0x2c0 kernel/time/posix-timers.c:940 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f757c87dea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f757d5480c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000df RAX: ffffffffffffffda RBX: 00007f757c9abf80 RCX: 00007f757c87dea9 RDX: 0000000020000300 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 00007f757c8ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f757c9abf80 R15: 00007ffcc6d2e648