FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 5.15.166-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.801/7889 is trying to acquire lock: ffffffff8c7fc438 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 but task is already holding lock: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:483 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11484 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4463 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4027 up+0x6e/0x90 kernel/locking/semaphore.c:190 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:256 console_unlock+0x1145/0x12b0 kernel/printk/printk.c:2760 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274 _printk+0xd1/0x120 kernel/printk/printk.c:2299 addrconf_notify+0xa80/0xf30 net/ipv6/addrconf.c:3659 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2018 [inline] netdev_state_change+0x1a3/0x250 net/core/dev.c:1409 linkwatch_do_dev+0x10c/0x160 net/core/link_watch.c:167 __linkwatch_run_queue+0x4ca/0x7f0 net/core/link_watch.c:213 linkwatch_event+0x48/0x50 net/core/link_watch.c:252 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #0 ((console_sem).lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x36c/0x4c0 lib/fault-inject.c:146 __copy_to_user_inatomic include/linux/uaccess.h:133 [inline] copy_to_user_nofault+0xdd/0x1c0 mm/maccess.c:255 bpf_prog_6303d92f98284ad8+0x3b/0x488 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918 __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220 trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:643 fsnotify_parent include/linux/fsnotify.h:62 [inline] fsnotify_file include/linux/fsnotify.h:105 [inline] fsnotify_modify include/linux/fsnotify.h:323 [inline] vfs_write+0x5c5/0xe50 fs/read_write.c:598 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock((console_sem).lock); *** DEADLOCK *** 4 locks held by syz.1.801/7889: #0: ffff888077598870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1084 #1: ffff88805b3b8460 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590 #2: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:483 #3: ffffffff8c91fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 7889 Comm: syz.1.801 Not tainted 5.15.166-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x36c/0x4c0 lib/fault-inject.c:146 __copy_to_user_inatomic include/linux/uaccess.h:133 [inline] copy_to_user_nofault+0xdd/0x1c0 mm/maccess.c:255 bpf_prog_6303d92f98284ad8+0x3b/0x488 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918 __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220 trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:643 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline] RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] RIP: 0010:fsnotify_parent include/linux/fsnotify.h:62 [inline] RIP: 0010:fsnotify_file include/linux/fsnotify.h:105 [inline] RIP: 0010:fsnotify_modify include/linux/fsnotify.h:323 [inline] RIP: 0010:vfs_write+0x5c5/0xe50 fs/read_write.c:598 Code: 21 10 f5 ff 4c 8b 2b 49 8d 5d 28 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 04 10 f5 ff 41 bc d0 07 00 00 4c 03 23 <4c> 89 e7 be 08 00 00 00 e8 7e 11 f5 ff 4c 89 e0 48 c1 e8 03 48 b9 RSP: 0018:ffffc90003097ca0 EFLAGS: 00000282 RAX: 1ffff1100e8e02ba RBX: ffff8880747015d0 RCX: ffff88801ec71dc0 RDX: ffff88801ec71dc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003097e30 R08: ffffffff81d5106c R09: ffffed1003d8e3be R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805b3b87d0 R13: ffff8880747015a8 R14: 1ffff92000612fa0 R15: 0000000000000001 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3dfc90f9df Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48 RSP: 002b:00007f3dfad8a030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f3dfc90f9df RDX: 0000000000000001 RSI: 00007f3dfad8a090 RDI: 0000000000000006 RBP: 00007f3dfad8a090 R08: 0000000000000000 R09: 00007f3dfad89df7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f3dfcac9f80 R15: 00007ffe8dba81d8 CPU: 1 PID: 7889 Comm: syz.1.801 Not tainted 5.15.166-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x38a/0x4c0 lib/fault-inject.c:146 __copy_to_user_inatomic include/linux/uaccess.h:133 [inline] copy_to_user_nofault+0xdd/0x1c0 mm/maccess.c:255 bpf_prog_6303d92f98284ad8+0x3b/0x488 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918 __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220 trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:643 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline] RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] RIP: 0010:fsnotify_parent include/linux/fsnotify.h:62 [inline] RIP: 0010:fsnotify_file include/linux/fsnotify.h:105 [inline] RIP: 0010:fsnotify_modify include/linux/fsnotify.h:323 [inline] RIP: 0010:vfs_write+0x5c5/0xe50 fs/read_write.c:598 Code: 21 10 f5 ff 4c 8b 2b 49 8d 5d 28 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 04 10 f5 ff 41 bc d0 07 00 00 4c 03 23 <4c> 89 e7 be 08 00 00 00 e8 7e 11 f5 ff 4c 89 e0 48 c1 e8 03 48 b9 RSP: 0018:ffffc90003097ca0 EFLAGS: 00000282 RAX: 1ffff1100e8e02ba RBX: ffff8880747015d0 RCX: ffff88801ec71dc0 RDX: ffff88801ec71dc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003097e30 R08: ffffffff81d5106c R09: ffffed1003d8e3be R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805b3b87d0 R13: ffff8880747015a8 R14: 1ffff92000612fa0 R15: 0000000000000001 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3dfc90f9df Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48 RSP: 002b:00007f3dfad8a030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f3dfc90f9df RDX: 0000000000000001 RSI: 00007f3dfad8a090 RDI: 0000000000000006 RBP: 00007f3dfad8a090 R08: 0000000000000000 R09: 00007f3dfad89df7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f3dfcac9f80 R15: 00007ffe8dba81d8 ---------------- Code disassembly (best guess): 0: 21 10 and %edx,(%rax) 2: f5 cmc 3: ff 4c 8b 2b decl 0x2b(%rbx,%rcx,4) 7: 49 8d 5d 28 lea 0x28(%r13),%rbx b: 48 89 d8 mov %rbx,%rax e: 48 c1 e8 03 shr $0x3,%rax 12: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 17: 74 08 je 0x21 19: 48 89 df mov %rbx,%rdi 1c: e8 04 10 f5 ff call 0xfff51025 21: 41 bc d0 07 00 00 mov $0x7d0,%r12d 27: 4c 03 23 add (%rbx),%r12 * 2a: 4c 89 e7 mov %r12,%rdi <-- trapping instruction 2d: be 08 00 00 00 mov $0x8,%esi 32: e8 7e 11 f5 ff call 0xfff511b5 37: 4c 89 e0 mov %r12,%rax 3a: 48 c1 e8 03 shr $0x3,%rax 3e: 48 rex.W 3f: b9 .byte 0xb9