./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor2083826452 <...> DUID 00:04:06:88:74:a7:04:75:62:cb:55:93:34:09:94:90:e1:fe forked to background, child pid 3178 [ 27.577682][ T3179] 8021q: adding VLAN 0 to HW filter on device bond0 [ 27.590129][ T3179] eql: remember to turn off Van-Jacobson compression on your slave devices Starting sshd: OK syzkaller Warning: Permanently added '10.128.1.88' (ECDSA) to the list of known hosts. execve("./syz-executor2083826452", ["./syz-executor2083826452"], 0x7ffc1afd3c20 /* 10 vars */) = 0 brk(NULL) = 0x555555896000 brk(0x555555896c40) = 0x555555896c40 arch_prctl(ARCH_SET_FS, 0x555555896300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 set_tid_address(0x5555558965d0) = 3607 set_robust_list(0x5555558965e0, 24) = 0 rt_sigaction(SIGRTMIN, {sa_handler=0x7ff9a536cc30, sa_mask=[], sa_flags=SA_RESTORER|SA_SIGINFO, sa_restorer=0x7ff9a536d300}, NULL, 8) = 0 rt_sigaction(SIGRT_1, {sa_handler=0x7ff9a536ccd0, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, sa_restorer=0x7ff9a536d300}, NULL, 8) = 0 rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0 prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0 readlink("/proc/self/exe", "/root/syz-executor2083826452", 4096) = 28 brk(0x5555558b7c40) = 0x5555558b7c40 brk(0x5555558b8000) = 0x5555558b8000 mprotect(0x7ff9a542d000, 16384, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 futex(0x7ff9a543340c, FUTEX_WAKE_PRIVATE, 1000000) = 0 mmap(NULL, 135168, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7ff9a533d000 mprotect(0x7ff9a533e000, 131072, PROT_READ|PROT_WRITE) = 0 clone(child_stack=0x7ff9a535d3f0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID./strace-static-x86_64: Process 3608 attached , parent_tid=[3608], tls=0x7ff9a535d700, child_tidptr=0x7ff9a535d9d0) = 3608 [pid 3608] set_robust_list(0x7ff9a535d9e0, 24 [pid 3607] futex(0x7ff9a5433408, FUTEX_WAKE_PRIVATE, 1000000 [pid 3608] <... set_robust_list resumed>) = 0 [pid 3608] pipe( [pid 3607] <... futex resumed>) = 0 [pid 3608] <... pipe resumed>[3, 4]) = 0 [pid 3607] futex(0x7ff9a543340c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 3608] futex(0x7ff9a543340c, FUTEX_WAKE_PRIVATE, 1000000 [pid 3607] <... futex resumed>) = -1 EAGAIN (Resource temporarily unavailable) [pid 3608] <... futex resumed>) = 0 [pid 3608] futex(0x7ff9a5433408, FUTEX_WAIT_PRIVATE, 0, NULL [pid 3607] futex(0x7ff9a5433408, FUTEX_WAKE_PRIVATE, 1000000) = 1 [pid 3608] <... futex resumed>) = 0 [pid 3608] pipe2([5, 6], O_EXCL) = 0 [pid 3607] futex(0x7ff9a543340c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 3608] futex(0x7ff9a543340c, FUTEX_WAKE_PRIVATE, 1000000) = 1 [pid 3607] <... futex resumed>) = 0 [pid 3607] futex(0x7ff9a5433408, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 3607] futex(0x7ff9a543340c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 3608] splice(3, NULL, 6, NULL, 511, 0 [pid 3607] <... futex resumed>) = -1 ETIMEDOUT (Connection timed out) [pid 3607] futex(0x7ff9a543341c, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 3607] mmap(NULL, 135168, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7ff9a531c000 [pid 3607] mprotect(0x7ff9a531d000, 131072, PROT_READ|PROT_WRITE) = 0 [pid 3607] clone(child_stack=0x7ff9a533c3f0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID./strace-static-x86_64: Process 3609 attached , parent_tid=[3609], tls=0x7ff9a533c700, child_tidptr=0x7ff9a533c9d0) = 3609 [pid 3607] futex(0x7ff9a5433418, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 3607] futex(0x7ff9a543341c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 3609] set_robust_list(0x7ff9a533c9e0, 24) = 0 [pid 3609] vmsplice(4, [{iov_base="\xb5", iov_len=1}], 1, 0) = 1 [pid 3609] futex(0x7ff9a543341c, FUTEX_WAKE_PRIVATE, 1000000) = 1 [pid 3607] <... futex resumed>) = 0 syzkaller login: [ 44.583127][ T3608] [ 44.585504][ T3608] ============================================ [ 44.591642][ T3608] WARNING: possible recursive locking detected [ 44.597776][ T3608] 5.19.0-rc4-next-20220628-syzkaller #0 Not tainted [ 44.604362][ T3608] -------------------------------------------- [ 44.610491][ T3608] syz-executor208/3608 is trying to acquire lock: [ 44.616882][ T3608] ffff8880226e0c68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x132/0x1bf0 [ 44.625661][ T3608] [ 44.625661][ T3608] but task is already holding lock: [ 44.633336][ T3608] ffff8880226e1068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x39b/0x420 [ 44.642725][ T3608] [ 44.642725][ T3608] other info that might help us debug this: [ 44.650846][ T3608] Possible unsafe locking scenario: [ 44.650846][ T3608] [ 44.658288][ T3608] CPU0 [ 44.661554][ T3608] ---- [ 44.664819][ T3608] lock(&pipe->mutex/1); [ 44.669151][ T3608] lock(&pipe->mutex/1); [ 44.673505][ T3608] [ 44.673505][ T3608] *** DEADLOCK *** [ 44.673505][ T3608] [ 44.681639][ T3608] May be due to missing lock nesting notation [ 44.681639][ T3608] [ 44.689945][ T3608] 1 lock held by syz-executor208/3608: [ 44.695417][ T3608] #0: ffff8880226e1068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x39b/0x420 [ 44.705358][ T3608] [ 44.705358][ T3608] stack backtrace: [ 44.711841][ T3608] CPU: 1 PID: 3608 Comm: syz-executor208 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 [ 44.721822][ T3608] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 [ 44.731881][ T3608] Call Trace: [ 44.735183][ T3608] [ 44.738110][ T3608] dump_stack_lvl+0xcd/0x134 [ 44.742725][ T3608] __lock_acquire.cold+0x1f5/0x3b4 [ 44.747843][ T3608] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 44.753831][ T3608] lock_acquire+0x1ab/0x570 [ 44.758330][ T3608] ? pipe_write+0x132/0x1bf0 [ 44.762919][ T3608] ? lock_release+0x780/0x780 [ 44.767594][ T3608] __mutex_lock+0x12f/0x1350 [ 44.772179][ T3608] ? pipe_write+0x132/0x1bf0 [ 44.776760][ T3608] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 44.782756][ T3608] ? pipe_write+0x132/0x1bf0 [ 44.787340][ T3608] ? mutex_lock_io_nested+0x1190/0x1190 [ 44.792885][ T3608] ? find_held_lock+0x2d/0x110 [ 44.797656][ T3608] ? aa_file_perm+0x56b/0x1230 [ 44.802417][ T3608] ? lock_downgrade+0x6e0/0x6e0 [ 44.807260][ T3608] pipe_write+0x132/0x1bf0 [ 44.811670][ T3608] ? aa_file_perm+0x595/0x1230 [ 44.816432][ T3608] ? do_proc_dopipe_max_size_conv+0x1c0/0x1c0 [ 44.822495][ T3608] ? aa_path_link+0x2f0/0x2f0 [ 44.827167][ T3608] ? mutex_lock_io_nested+0x1190/0x1190 [ 44.832711][ T3608] ? pipe_wait_readable+0x336/0x420 [ 44.837907][ T3608] ? lock_downgrade+0x6e0/0x6e0 [ 44.842753][ T3608] do_iter_readv_writev+0x360/0x5c0 [ 44.847945][ T3608] ? ksys_lseek+0x1b0/0x1b0 [ 44.852455][ T3608] ? bpf_lsm_file_permission+0x5/0x10 [ 44.858001][ T3608] ? security_file_permission+0xab/0xd0 [ 44.863543][ T3608] do_iter_write+0x182/0x700 [ 44.868131][ T3608] vfs_iter_write+0x70/0xa0 [ 44.872628][ T3608] iter_file_splice_write+0x723/0xc70 [ 44.878009][ T3608] ? page_cache_pipe_buf_confirm+0x5b0/0x5b0 [ 44.883989][ T3608] ? __lock_acquire+0xbca/0x5660 [ 44.888923][ T3608] ? bpf_lsm_file_permission+0x5/0x10 [ 44.894294][ T3608] ? security_file_permission+0xab/0xd0 [ 44.899849][ T3608] ? page_cache_pipe_buf_confirm+0x5b0/0x5b0 [ 44.905838][ T3608] do_splice+0xb57/0x1920 [ 44.910161][ T3608] ? find_held_lock+0x2d/0x110 [ 44.914927][ T3608] ? splice_file_to_pipe+0x120/0x120 [ 44.920201][ T3608] ? lock_downgrade+0x6e0/0x6e0 [ 44.925047][ T3608] __do_splice+0x134/0x250 [ 44.929458][ T3608] ? do_splice+0x1920/0x1920 [ 44.934040][ T3608] __x64_sys_splice+0x198/0x250 [ 44.938895][ T3608] do_syscall_64+0x35/0xb0 [ 44.943310][ T3608] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 44.949196][ T3608] RIP: 0033:0x7ff9a53aac99 [ 44.953602][ T3608] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 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 b8 ff ff ff f7 d8 64 89 01 48 [ 44.973199][ T3608] RSP: 002b:00007ff9a535d308 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 [pid 3609] futex(0x7ff9a5433418, FUTEX_WAIT_PRIVATE, 0, NULL [pid 3608] <... splice resumed>) = -1 EXDEV (Invalid cross-device link) [pid 3608] futex(0x7ff9a543340c, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 3607] exit_group(0) = ? [pid 3609] <... futex resumed>) = ? [pid 3609] +++ exited with 0 +++ [pid 3608] +++ exited with 0 +++ +++ exited with 0 +++ [ 44.981607][ T3608] RAX: ffffffffffff