Warning: Permanently added '10.128.0.18' (ECDSA) to the list of known hosts. executing program [ 53.179403] [ 53.181074] ====================================================== [ 53.187515] WARNING: possible circular locking dependency detected [ 53.193905] 5.0.0-rc1+ #19 Not tainted [ 53.197778] ------------------------------------------------------ [ 53.204088] syz-executor726/7996 is trying to acquire lock: [ 53.209775] 000000007b765402 (&pipe->mutex/1){+.+.}, at: fifo_open+0x159/0xb00 [ 53.217131] [ 53.217131] but task is already holding lock: [ 53.223079] 0000000025d774c2 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 [ 53.232540] [ 53.232540] which lock already depends on the new lock. [ 53.232540] [ 53.240907] [ 53.240907] the existing dependency chain (in reverse order) is: [ 53.248702] [ 53.248702] -> #1 (&sig->cred_guard_mutex){+.+.}: [ 53.255032] __mutex_lock+0x12f/0x1670 [ 53.259433] mutex_lock_interruptible_nested+0x16/0x20 [ 53.265228] proc_pid_attr_write+0x1fa/0x530 [ 53.270221] __vfs_write+0x116/0xb40 [ 53.274458] __kernel_write+0x110/0x3b0 [ 53.278945] write_pipe_buf+0x180/0x240 [ 53.283426] __splice_from_pipe+0x39a/0x7e0 [ 53.288257] splice_from_pipe+0x1ea/0x310 [ 53.292913] default_file_splice_write+0x3c/0x90 [ 53.298253] do_splice+0x64b/0x1410 [ 53.302401] __x64_sys_splice+0x2c6/0x330 [ 53.307140] do_syscall_64+0x1a3/0x800 [ 53.311555] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.317352] [ 53.317352] -> #0 (&pipe->mutex/1){+.+.}: [ 53.322985] lock_acquire+0x1db/0x570 [ 53.327328] __mutex_lock+0x12f/0x1670 [ 53.331758] mutex_lock_nested+0x16/0x20 [ 53.336337] fifo_open+0x159/0xb00 [ 53.340385] do_dentry_open+0x48a/0x1210 [ 53.344952] vfs_open+0xa0/0xd0 [ 53.348740] path_openat+0x144f/0x5650 [ 53.353134] do_filp_open+0x26f/0x370 [ 53.357437] do_open_execat+0x20e/0x930 [ 53.361916] __do_execve_file.isra.0+0x1966/0x2700 [ 53.367367] __x64_sys_execve+0x8f/0xc0 [ 53.371847] do_syscall_64+0x1a3/0x800 [ 53.376401] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.382086] [ 53.382086] other info that might help us debug this: [ 53.382086] [ 53.390201] Possible unsafe locking scenario: [ 53.390201] [ 53.396227] CPU0 CPU1 [ 53.400864] ---- ---- [ 53.405504] lock(&sig->cred_guard_mutex); [ 53.409799] lock(&pipe->mutex/1); [ 53.415917] lock(&sig->cred_guard_mutex); [ 53.422732] lock(&pipe->mutex/1); [ 53.426425] [ 53.426425] *** DEADLOCK *** [ 53.426425] [ 53.432476] 1 lock held by syz-executor726/7996: [ 53.437206] #0: 0000000025d774c2 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 [ 53.447005] [ 53.447005] stack backtrace: [ 53.451485] CPU: 0 PID: 7996 Comm: syz-executor726 Not tainted 5.0.0-rc1+ #19 [ 53.458738] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.468073] Call Trace: [ 53.470656] dump_stack+0x1db/0x2d0 [ 53.474262] ? dump_stack_print_info.cold+0x20/0x20 [ 53.479260] ? print_stack_trace+0x77/0xb0 [ 53.483499] ? vprintk_func+0x86/0x189 [ 53.487422] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 53.492781] __lock_acquire+0x3014/0x4a30 [ 53.496913] ? is_bpf_text_address+0xac/0x170 [ 53.501396] ? mark_held_locks+0x100/0x100 [ 53.505614] ? mark_held_locks+0xb1/0x100 [ 53.509756] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 53.514854] ? lockdep_hardirqs_on+0x415/0x5d0 [ 53.519428] ? trace_hardirqs_off_caller+0x300/0x300 [ 53.524516] ? do_raw_spin_trylock+0x270/0x270 [ 53.529093] ? add_lock_to_list.isra.0+0x450/0x450 [ 53.534016] ? print_usage_bug+0xd0/0xd0 [ 53.538066] ? __lock_is_held+0xb6/0x140 [ 53.542109] lock_acquire+0x1db/0x570 [ 53.545899] ? fifo_open+0x159/0xb00 [ 53.549603] ? ___might_sleep+0x1e7/0x310 [ 53.553736] ? lock_release+0xc40/0xc40 [ 53.557695] ? fifo_open+0x159/0xb00 [ 53.561393] ? fifo_open+0x159/0xb00 [ 53.565088] __mutex_lock+0x12f/0x1670 [ 53.568960] ? fifo_open+0x159/0xb00 [ 53.572654] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.578178] ? fifo_open+0x159/0xb00 [ 53.581881] ? check_preemption_disabled+0x48/0x290 [ 53.586888] ? lockdep_init_map+0x10c/0x5b0 [ 53.591199] ? mutex_trylock+0x2d0/0x2d0 [ 53.595261] ? add_lock_to_list.isra.0+0x450/0x450 [ 53.600197] ? __mutex_init+0x1f6/0x2a0 [ 53.604168] ? psi_task_change.cold+0x1ec/0x1ec [ 53.608946] ? fifo_open+0x2b5/0xb00 [ 53.612652] ? find_held_lock+0x35/0x120 [ 53.616697] ? fifo_open+0x2b5/0xb00 [ 53.620397] ? lock_acquire+0x1db/0x570 [ 53.624359] ? kasan_check_read+0x11/0x20 [ 53.628507] ? do_raw_spin_unlock+0xa0/0x330 [ 53.632903] ? do_raw_spin_trylock+0x270/0x270 [ 53.637475] mutex_lock_nested+0x16/0x20 [ 53.641521] ? _raw_spin_unlock+0x2d/0x50 [ 53.645654] ? mutex_lock_nested+0x16/0x20 [ 53.649875] fifo_open+0x159/0xb00 [ 53.653398] do_dentry_open+0x48a/0x1210 [ 53.657480] ? pipe_release+0x280/0x280 [ 53.661437] ? chown_common+0x740/0x740 [ 53.665409] ? security_inode_permission+0xd5/0x110 [ 53.670526] ? inode_permission+0xb4/0x570 [ 53.674760] vfs_open+0xa0/0xd0 [ 53.678032] path_openat+0x144f/0x5650 [ 53.681914] ? is_bpf_text_address+0xd3/0x170 [ 53.686394] ? path_lookupat.isra.0+0xba0/0xba0 [ 53.691144] ? __lock_acquire+0x572/0x4a30 [ 53.695368] ? kmem_cache_alloc+0x12d/0x710 [ 53.699675] ? __do_execve_file.isra.0+0x47a/0x2700 [ 53.704671] ? __x64_sys_execve+0x8f/0xc0 [ 53.708823] ? do_syscall_64+0x1a3/0x800 [ 53.712951] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.718320] ? add_lock_to_list.isra.0+0x450/0x450 [ 53.723237] do_filp_open+0x26f/0x370 [ 53.727026] ? may_open_dev+0x100/0x100 [ 53.730986] ? refcount_add_not_zero_checked+0x330/0x330 [ 53.736423] ? prepare_creds+0xa4/0x4e0 [ 53.740386] ? add_lock_to_list.isra.0+0x450/0x450 [ 53.745309] ? add_lock_to_list.isra.0+0x450/0x450 [ 53.750231] ? __do_execve_file.isra.0+0x901/0x2700 [ 53.755236] do_open_execat+0x20e/0x930 [ 53.759199] ? unregister_binfmt+0x2b0/0x2b0 [ 53.763594] ? kasan_check_read+0x11/0x20 [ 53.767727] ? do_raw_spin_trylock+0x270/0x270 [ 53.772302] ? __phys_addr_symbol+0x30/0x70 [ 53.776611] __do_execve_file.isra.0+0x1966/0x2700 [ 53.781529] ? rcu_pm_notify+0xd0/0xd0 [ 53.785400] ? copy_strings_kernel+0x110/0x110 [ 53.789967] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 53.795492] ? strncpy_from_user+0x3aa/0x4e0 [ 53.799886] ? digsig_verify.cold+0x32/0x32 [ 53.804188] ? kmem_cache_alloc+0x341/0x710 [ 53.808496] ? do_syscall_64+0x8c/0x800 [ 53.812457] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.817987] ? getname_flags+0x277/0x5b0 [ 53.822041] ? trace_hardirqs_off_caller+0x300/0x300 [ 53.827129] __x64_sys_execve+0x8f/0xc0 [ 53.831090] do_syscall_64+0x1a3/0x800 [ 53.834962] ? syscall_return_slowpath+0x5f0/0x5f0 [ 53.839878] ? prepare_exit_to_usermode+0x232/0x3b0 [ 53.844883] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 53.849726] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.854893] RIP: 0033:0x440139 [ 53.858066] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 53.876969] RSP: 002b:00007ffd9855db28 EFLAGS: 00000217 ORIG_RAX: 000000000000003b [ 53.884661] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 0000000000440139 [ 53.891914] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000240 [ 53.899235] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 53.906498] R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004019c0 [ 53.913758] R13: 0000000000401a50 R14: 0000000000000000 R15: 0000000000000000