Warning: Permanently added '10.128.0.231' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 50.151816] [ 50.153491] ====================================================== [ 50.159799] WARNING: possible circular locking dependency detected [ 50.166093] 5.0.0-rc1+ #19 Not tainted [ 50.169956] ------------------------------------------------------ [ 50.176251] syz-executor885/8089 is trying to acquire lock: [ 50.181935] 00000000acf7bc8e (&pipe->mutex/1){+.+.}, at: fifo_open+0x159/0xb00 [ 50.189288] [ 50.189288] but task is already holding lock: [ 50.195237] 00000000183c916e (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 [ 50.204600] [ 50.204600] which lock already depends on the new lock. [ 50.204600] [ 50.212889] [ 50.212889] the existing dependency chain (in reverse order) is: [ 50.220484] [ 50.220484] -> #1 (&sig->cred_guard_mutex){+.+.}: [ 50.226796] __mutex_lock+0x12f/0x1670 [ 50.231200] mutex_lock_interruptible_nested+0x16/0x20 [ 50.236983] proc_pid_attr_write+0x1fa/0x530 [ 50.241893] __vfs_write+0x116/0xb40 [ 50.246107] __kernel_write+0x110/0x3b0 [ 50.250579] write_pipe_buf+0x180/0x240 [ 50.255053] __splice_from_pipe+0x39a/0x7e0 [ 50.259876] splice_from_pipe+0x1ea/0x310 [ 50.264536] default_file_splice_write+0x3c/0x90 [ 50.269790] do_splice+0x64b/0x1410 [ 50.273918] __x64_sys_splice+0x2c6/0x330 [ 50.278569] do_syscall_64+0x1a3/0x800 [ 50.282962] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.288664] [ 50.288664] -> #0 (&pipe->mutex/1){+.+.}: [ 50.294284] lock_acquire+0x1db/0x570 [ 50.298586] __mutex_lock+0x12f/0x1670 [ 50.302973] mutex_lock_nested+0x16/0x20 [ 50.307535] fifo_open+0x159/0xb00 [ 50.311575] do_dentry_open+0x48a/0x1210 [ 50.316152] vfs_open+0xa0/0xd0 [ 50.319934] path_openat+0x144f/0x5650 [ 50.324320] do_filp_open+0x26f/0x370 [ 50.328621] do_open_execat+0x20e/0x930 [ 50.333097] __do_execve_file.isra.0+0x1966/0x2700 [ 50.338527] __x64_sys_execve+0x8f/0xc0 [ 50.343004] do_syscall_64+0x1a3/0x800 [ 50.347410] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.353093] [ 50.353093] other info that might help us debug this: [ 50.353093] [ 50.361207] Possible unsafe locking scenario: [ 50.361207] [ 50.367243] CPU0 CPU1 [ 50.371887] ---- ---- [ 50.376529] lock(&sig->cred_guard_mutex); [ 50.380829] lock(&pipe->mutex/1); [ 50.386951] lock(&sig->cred_guard_mutex); [ 50.393766] lock(&pipe->mutex/1); [ 50.397385] [ 50.397385] *** DEADLOCK *** [ 50.397385] [ 50.403421] 1 lock held by syz-executor885/8089: [ 50.408151] #0: 00000000183c916e (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 [ 50.417938] [ 50.417938] stack backtrace: [ 50.422430] CPU: 0 PID: 8089 Comm: syz-executor885 Not tainted 5.0.0-rc1+ #19 [ 50.429684] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.439015] Call Trace: [ 50.441589] dump_stack+0x1db/0x2d0 [ 50.445212] ? dump_stack_print_info.cold+0x20/0x20 [ 50.450210] ? print_stack_trace+0x77/0xb0 [ 50.454429] ? vprintk_func+0x86/0x189 [ 50.458302] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 50.463656] __lock_acquire+0x3014/0x4a30 [ 50.467792] ? is_bpf_text_address+0xac/0x170 [ 50.472281] ? mark_held_locks+0x100/0x100 [ 50.476504] ? mark_held_locks+0xb1/0x100 [ 50.480634] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 50.485725] ? lockdep_hardirqs_on+0x415/0x5d0 [ 50.490292] ? trace_hardirqs_off_caller+0x300/0x300 [ 50.495381] ? do_raw_spin_trylock+0x270/0x270 [ 50.499948] ? add_lock_to_list.isra.0+0x450/0x450 [ 50.504865] ? print_usage_bug+0xd0/0xd0 [ 50.508909] ? __lock_is_held+0xb6/0x140 [ 50.512952] lock_acquire+0x1db/0x570 [ 50.516738] ? fifo_open+0x159/0xb00 [ 50.520434] ? ___might_sleep+0x1e7/0x310 [ 50.524568] ? lock_release+0xc40/0xc40 [ 50.528528] ? fifo_open+0x159/0xb00 [ 50.532225] ? fifo_open+0x159/0xb00 [ 50.535920] __mutex_lock+0x12f/0x1670 [ 50.539787] ? fifo_open+0x159/0xb00 [ 50.543491] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.549014] ? fifo_open+0x159/0xb00 [ 50.552717] ? check_preemption_disabled+0x48/0x290 [ 50.557717] ? lockdep_init_map+0x10c/0x5b0 [ 50.562024] ? mutex_trylock+0x2d0/0x2d0 [ 50.566082] ? add_lock_to_list.isra.0+0x450/0x450 [ 50.571012] ? __mutex_init+0x1f6/0x2a0 [ 50.574975] ? psi_task_change.cold+0x1ec/0x1ec [ 50.579627] ? fifo_open+0x2b5/0xb00 [ 50.583333] ? find_held_lock+0x35/0x120 [ 50.587378] ? fifo_open+0x2b5/0xb00 [ 50.591075] ? lock_acquire+0x1db/0x570 [ 50.595038] ? kasan_check_read+0x11/0x20 [ 50.599171] ? do_raw_spin_unlock+0xa0/0x330 [ 50.603566] ? do_raw_spin_trylock+0x270/0x270 [ 50.608135] mutex_lock_nested+0x16/0x20 [ 50.612183] ? _raw_spin_unlock+0x2d/0x50 [ 50.616311] ? mutex_lock_nested+0x16/0x20 [ 50.620532] fifo_open+0x159/0xb00 [ 50.624059] do_dentry_open+0x48a/0x1210 [ 50.628117] ? pipe_release+0x280/0x280 [ 50.632077] ? chown_common+0x740/0x740 [ 50.636039] ? security_inode_permission+0xd5/0x110 [ 50.641043] ? inode_permission+0xb4/0x570 [ 50.645266] vfs_open+0xa0/0xd0 [ 50.648528] path_openat+0x144f/0x5650 [ 50.652399] ? __lock_is_held+0xb6/0x140 [ 50.656448] ? path_lookupat.isra.0+0xba0/0xba0 [ 50.661100] ? __mutex_init+0x1f6/0x2a0 [ 50.665078] ? __lock_acquire+0x572/0x4a30 [ 50.669311] ? __do_execve_file.isra.0+0x47a/0x2700 [ 50.674312] ? __x64_sys_execve+0x8f/0xc0 [ 50.678444] ? do_syscall_64+0x1a3/0x800 [ 50.682491] do_filp_open+0x26f/0x370 [ 50.686277] ? may_open_dev+0x100/0x100 [ 50.690240] ? prepare_creds+0xa4/0x4e0 [ 50.694226] ? add_lock_to_list.isra.0+0x450/0x450 [ 50.699137] ? add_lock_to_list.isra.0+0x450/0x450 [ 50.704054] ? __do_execve_file.isra.0+0x901/0x2700 [ 50.709058] do_open_execat+0x20e/0x930 [ 50.713019] ? unregister_binfmt+0x2b0/0x2b0 [ 50.717413] ? kasan_check_read+0x11/0x20 [ 50.721546] ? do_raw_spin_trylock+0x270/0x270 [ 50.726114] ? __phys_addr_symbol+0x30/0x70 [ 50.730421] __do_execve_file.isra.0+0x1966/0x2700 [ 50.735338] ? rcu_pm_notify+0xd0/0xd0 [ 50.739210] ? copy_strings_kernel+0x110/0x110 [ 50.743778] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 50.749299] ? strncpy_from_user+0x3aa/0x4e0 [ 50.753697] ? digsig_verify.cold+0x32/0x32 [ 50.757999] ? kmem_cache_alloc+0x341/0x710 [ 50.762303] ? do_syscall_64+0x8c/0x800 [ 50.766259] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.771778] ? getname_flags+0x277/0x5b0 [ 50.775820] ? trace_hardirqs_off_caller+0x300/0x300 [ 50.780909] __x64_sys_execve+0x8f/0xc0 [ 50.784873] do_syscall_64+0x1a3/0x800 [ 50.788747] ? syscall_return_slowpath+0x5f0/0x5f0 [ 50.793674] ? prepare_exit_to_usermode+0x232/0x3b0 [ 50.798689] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 50.803521] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.808698] RIP: 0033:0x440139 [ 50.811873] 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 [ 50.830764] RSP: 002b:00007ffd84569018 EFLAGS: 00000217 ORIG_RAX: 000000000000003b [ 50.838460] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 0000000000440139 [ 50.845714] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000240 [ 50.852967] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 50.860219] R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004019c0 [ 50.867475] R13: 0000000000401a50 R14: 0000000000000000 R15: 0000000000000000