======================================================== WARNING: possible irq lock inversion dependency detected 6.7.0-rc1-next-20231117-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.0/8945 just changed the state of lock: ffff88807f2fc4a0 (&new_timer->it_lock){-...}-{2:2}, at: posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 but this lock took another, HARDIRQ-unsafe lock in the past: (&sighand->siglock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sighand->siglock); local_irq_disable(); lock(&new_timer->it_lock); lock(&sighand->siglock); lock(&new_timer->it_lock); *** DEADLOCK *** no locks held by syz-executor.0/8945. the shortest dependencies between 2nd lock and 1st lock: -> (&sighand->siglock){+.+.}-{2:2} { HARDIRQ-ON-W 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 SOFTIRQ-ON-W 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 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] calculate_sigpending+0x44/0xa0 kernel/signal.c:197 ret_from_fork+0x23/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 } ... key at: [] __key.341+0x0/0x40 ... acquired at: __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] __do_sys_timer_delete kernel/time/posix-timers.c:1023 [inline] __se_sys_timer_delete kernel/time/posix-timers.c:1006 [inline] __x64_sys_timer_delete+0x16a/0x3e0 kernel/time/posix-timers.c:1006 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 -> (&new_timer->it_lock){-...}-{2:2} { IN-HARDIRQ-W at: 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 posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 __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 get_current arch/x86/include/asm/current.h:48 [inline] finish_task_switch.isra.0+0x220/0xcb0 kernel/sched/core.c:5273 context_switch kernel/sched/core.c:5402 [inline] __schedule+0xf1d/0x5c00 kernel/sched/core.c:6726 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe7/0x270 kernel/sched/core.c:6816 schedule_timeout+0x254/0x290 kernel/time/timer.c:2143 unix_wait_for_peer+0x24c/0x280 net/unix/af_unix.c:1476 unix_dgram_sendmsg+0x19eb/0x1ca0 net/unix/af_unix.c:2080 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2724 __do_sys_sendmmsg net/socket.c:2753 [inline] __se_sys_sendmmsg net/socket.c:2750 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2750 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 INITIAL USE at: 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 itimer_delete kernel/time/posix-timers.c:1048 [inline] exit_itimers+0x255/0x560 kernel/time/posix-timers.c:1109 do_exit+0x629/0x2ad0 kernel/exit.c:845 do_group_exit+0xd3/0x2a0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1030 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 } ... key at: [] __key.0+0x0/0x40 ... acquired at: 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 posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 __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 get_current arch/x86/include/asm/current.h:48 [inline] finish_task_switch.isra.0+0x220/0xcb0 kernel/sched/core.c:5273 context_switch kernel/sched/core.c:5402 [inline] __schedule+0xf1d/0x5c00 kernel/sched/core.c:6726 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe7/0x270 kernel/sched/core.c:6816 schedule_timeout+0x254/0x290 kernel/time/timer.c:2143 unix_wait_for_peer+0x24c/0x280 net/unix/af_unix.c:1476 unix_dgram_sendmsg+0x19eb/0x1ca0 net/unix/af_unix.c:2080 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2724 __do_sys_sendmmsg net/socket.c:2753 [inline] __se_sys_sendmmsg net/socket.c:2750 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2750 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 stack backtrace: CPU: 0 PID: 8945 Comm: syz-executor.0 Not tainted 6.7.0-rc1-next-20231117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_irq_inversion_bug.part.0+0x3e1/0x590 kernel/locking/lockdep.c:4079 print_irq_inversion_bug kernel/locking/lockdep.c:4032 [inline] check_usage_forwards kernel/locking/lockdep.c:4110 [inline] mark_lock_irq kernel/locking/lockdep.c:4242 [inline] mark_lock+0x570/0xc50 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 posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 __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:finish_task_switch.isra.0+0x220/0xcb0 kernel/sched/core.c:5273 Code: 90 0a 00 00 44 8b 0d 27 ca bd 0d 45 85 c9 0f 85 bc 01 00 00 48 89 df e8 ce f8 ff ff e8 29 7c 33 00 fb 65 48 8b 1d b0 6f a8 7e <48> 8d bb d8 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc90015c874a8 EFLAGS: 00000206 RAX: 000000000000cb05 RBX: ffff88803c009dc0 RCX: 1ffffffff1e31619 RDX: 0000000000000000 RSI: ffffffff8accbfe0 RDI: ffffffff8b2f1520 RBP: ffffc90015c874f0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8f18e357 R11: 0000000000000000 R12: ffff8880b983d478 R13: ffff888026b9d940 R14: 0000000000000000 R15: ffff8880b983c700 context_switch kernel/sched/core.c:5402 [inline] __schedule+0xf1d/0x5c00 kernel/sched/core.c:6726 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe7/0x270 kernel/sched/core.c:6816 schedule_timeout+0x254/0x290 kernel/time/timer.c:2143 unix_wait_for_peer+0x24c/0x280 net/unix/af_unix.c:1476 unix_dgram_sendmsg+0x19eb/0x1ca0 net/unix/af_unix.c:2080 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2724 __do_sys_sendmmsg net/socket.c:2753 [inline] __se_sys_sendmmsg net/socket.c:2750 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2750 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 RIP: 0033:0x7f684a47cae9 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:00007f684b2b50c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f684a59bf80 RCX: 00007f684a47cae9 RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004 RBP: 00007f684a4c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f684a59bf80 R15: 00007fff369ddad8 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 00 00 add %al,(%rax) 2: 44 8b 0d 27 ca bd 0d mov 0xdbdca27(%rip),%r9d # 0xdbdca30 9: 45 85 c9 test %r9d,%r9d c: 0f 85 bc 01 00 00 jne 0x1ce 12: 48 89 df mov %rbx,%rdi 15: e8 ce f8 ff ff call 0xfffff8e8 1a: e8 29 7c 33 00 call 0x337c48 1f: fb sti 20: 65 48 8b 1d b0 6f a8 mov %gs:0x7ea86fb0(%rip),%rbx # 0x7ea86fd8 27: 7e * 28: 48 8d bb d8 15 00 00 lea 0x15d8(%rbx),%rdi <-- trapping instruction 2f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 36: fc ff df 39: 48 89 fa mov %rdi,%rdx 3c: 48 rex.W 3d: c1 .byte 0xc1