================================ WARNING: inconsistent lock state 6.7.0-rc1-next-20231117-syzkaller #0 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. kworker/u4:2/39 [HC1[1]:SC0[0]:HE0:SE1] takes: ffff88803997a518 (&sighand->siglock){?.+.}-{2:2}, at: __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 {HARDIRQ-ON-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:530 [inline] ptrace_set_stopped kernel/ptrace.c:391 [inline] ptrace_attach+0x401/0x650 kernel/ptrace.c:478 __do_sys_ptrace+0x204/0x230 kernel/ptrace.c:1290 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a irq event stamp: 1765760 hardirqs last enabled at (1765759): [] __local_bh_enable_ip+0xa4/0x120 kernel/softirq.c:386 hardirqs last disabled at (1765760): [] sysvec_apic_timer_interrupt+0xe/0xb0 arch/x86/kernel/apic/apic.c:1076 softirqs last enabled at (1765758): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (1765758): [] batadv_nc_purge_paths+0x1ce/0x3c0 net/batman-adv/network-coding.c:471 softirqs last disabled at (1765756): [] spin_lock_bh include/linux/spinlock.h:356 [inline] softirqs last disabled at (1765756): [] batadv_nc_purge_paths+0xd3/0x3c0 net/batman-adv/network-coding.c:442 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sighand->siglock); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by kworker/u4:2/39: #0: ffff88814bc2c538 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x78c/0x15f0 kernel/workqueue.c:2611 #1: ffffc90000affd80 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7f6/0x15f0 kernel/workqueue.c:2612 #2: ffff888023f601b0 (&new_timer->it_lock){-...}-{2:2}, at: posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 #3: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #3: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #3: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: send_sigqueue+0x10c/0x840 kernel/signal.c:1978 #4: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #4: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #4: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x3f/0x340 kernel/signal.c:1405 stack backtrace: CPU: 0 PID: 39 Comm: kworker/u4:2 Not tainted 6.7.0-rc1-next-20231117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:3970 [inline] valid_state kernel/locking/lockdep.c:4012 [inline] mark_lock_irq kernel/locking/lockdep.c:4215 [inline] mark_lock+0x91a/0xc50 kernel/locking/lockdep.c:4677 mark_usage kernel/locking/lockdep.c:4563 [inline] __lock_acquire+0x1347/0x3b10 kernel/locking/lockdep.c:5090 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 lock_task_sighand include/linux/sched/signal.h:748 [inline] send_sigqueue+0x1d4/0x840 kernel/signal.c:1996 posix_timer_event kernel/time/posix-timers.c:298 [inline] posix_timer_fn+0x181/0x3d0 kernel/time/posix-timers.c:324 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10c/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__local_bh_disable_ip+0x0/0xc0 kernel/softirq.c:303 Code: 00 00 00 48 8b 44 24 78 65 48 2b 04 25 28 00 00 00 75 07 48 83 ec 80 5b 5d c3 e8 db 37 31 09 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1e fa 55 53 89 f3 65 8b 05 79 eb b3 7e a9 00 00 0f 00 0f 85 RSP: 0018:ffffc90000affb18 EFLAGS: 00000282 RAX: ffffed1005335899 RBX: ffff88803c074740 RCX: ffffffff8a49233f RDX: ffff888016ee8000 RSI: 0000000000000201 RDI: ffffffff8a492213 RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000080 R10: 000000000000001d R11: 0000000000000002 R12: ffffffff8a492500 R13: ffff88803bffcc80 R14: ffff8880299ac4c0 R15: ffff8880288bd0e8 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:125 [inline] _raw_spin_lock_bh+0x17/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xd3/0x3c0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x97a/0x10e0 net/batman-adv/network-coding.c:720 process_one_work+0x8a4/0x15f0 kernel/workqueue.c:2636 process_scheduled_works kernel/workqueue.c:2709 [inline] worker_thread+0x8b6/0x1290 kernel/workqueue.c:2790 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 48 8b add %cl,-0x75(%rax) 5: 44 24 78 rex.R and $0x78,%al 8: 65 48 2b 04 25 28 00 sub %gs:0x28,%rax f: 00 00 11: 75 07 jne 0x1a 13: 48 83 ec 80 sub $0xffffffffffffff80,%rsp 17: 5b pop %rbx 18: 5d pop %rbp 19: c3 ret 1a: e8 db 37 31 09 call 0x93137fa 1f: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) 26: 00 00 00 00 * 2a: f3 0f 1e fa endbr64 <-- trapping instruction 2e: 55 push %rbp 2f: 53 push %rbx 30: 89 f3 mov %esi,%ebx 32: 65 8b 05 79 eb b3 7e mov %gs:0x7eb3eb79(%rip),%eax # 0x7eb3ebb2 39: a9 00 00 0f 00 test $0xf0000,%eax 3e: 0f .byte 0xf 3f: 85 .byte 0x85