./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor1494598273 <...> DUID 00:04:23:68:77:f1:65:66:05:56:fc:6e:24:65:03:30:d5:25 forked to background, child pid 4667 [ 19.802614][ T4668] 8021q: adding VLAN 0 to HW filter on device bond0 [ 19.811675][ T4668] eql: remember to turn off Van-Jacobson compression on your slave devices Starting sshd: OK syzkaller Warning: Permanently added '10.128.0.223' (ECDSA) to the list of known hosts. execve("./syz-executor1494598273", ["./syz-executor1494598273"], 0x7ffdb0fa7870 /* 10 vars */) = 0 brk(NULL) = 0x55555638c000 brk(0x55555638cc40) = 0x55555638cc40 arch_prctl(ARCH_SET_FS, 0x55555638c300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 set_tid_address(0x55555638c5d0) = 4998 set_robust_list(0x55555638c5e0, 24) = 0 rt_sigaction(SIGRTMIN, {sa_handler=0x7fcf44a96f20, sa_mask=[], sa_flags=SA_RESTORER|SA_SIGINFO, sa_restorer=0x7fcf44a975f0}, NULL, 8) = 0 rt_sigaction(SIGRT_1, {sa_handler=0x7fcf44a96fc0, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, sa_restorer=0x7fcf44a975f0}, 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-executor1494598273", 4096) = 28 brk(0x5555563adc40) = 0x5555563adc40 brk(0x5555563ae000) = 0x5555563ae000 mprotect(0x7fcf44b57000, 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(0x7fcf44b5d40c, FUTEX_WAKE_PRIVATE, 1000000) = 0 mmap(NULL, 135168, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7fcf44a67000 mprotect(0x7fcf44a68000, 131072, PROT_READ|PROT_WRITE) = 0 clone(child_stack=0x7fcf44a873f0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tid=[4999], tls=0x7fcf44a87700, child_tidptr=0x7fcf44a879d0) = 4999 futex(0x7fcf44b5d408, FUTEX_WAKE_PRIVATE, 1000000) = 0 futex(0x7fcf44b5d40c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000}./strace-static-x86_64: Process 4999 attached [pid 4999] set_robust_list(0x7fcf44a879e0, 24) = 0 [pid 4999] pipe2([3, 4], 0) = 0 [pid 4999] futex(0x7fcf44b5d40c, FUTEX_WAKE_PRIVATE, 1000000) = 1 [pid 4999] futex(0x7fcf44b5d408, FUTEX_WAIT_PRIVATE, 0, NULL [pid 4998] <... futex resumed>) = 0 [pid 4998] futex(0x7fcf44b5d408, FUTEX_WAKE_PRIVATE, 1000000) = 1 [pid 4999] <... futex resumed>) = 0 [pid 4998] futex(0x7fcf44b5d40c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 4999] pipe2([5, 6], O_EXCL|O_NONBLOCK) = 0 [pid 4999] futex(0x7fcf44b5d40c, FUTEX_WAKE_PRIVATE, 1000000 [pid 4998] <... futex resumed>) = 0 [pid 4999] <... futex resumed>) = 1 [pid 4998] futex(0x7fcf44b5d408, FUTEX_WAKE_PRIVATE, 1000000 [pid 4999] openat(AT_FDCWD, "/proc/thread-self/fd/4", O_RDWR [pid 4998] <... futex resumed>) = 0 [pid 4999] <... openat resumed>) = 7 [pid 4998] futex(0x7fcf44b5d40c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 4999] futex(0x7fcf44b5d40c, FUTEX_WAKE_PRIVATE, 1000000 [pid 4998] <... futex resumed>) = -1 EAGAIN (Resource temporarily unavailable) [pid 4999] <... futex resumed>) = 0 [pid 4998] futex(0x7fcf44b5d408, FUTEX_WAKE_PRIVATE, 1000000 [pid 4999] splice(7, NULL, 6, NULL, 256, 0 [pid 4998] <... futex resumed>) = 0 [pid 4998] futex(0x7fcf44b5d40c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000}) = -1 ETIMEDOUT (Connection timed out) [pid 4998] futex(0x7fcf44b5d40c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=0}) = -1 ETIMEDOUT (Connection timed out) [pid 4998] futex(0x7fcf44b5d40c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=0}) = -1 ETIMEDOUT (Connection timed out) [pid 4998] futex(0x7fcf44b5d41c, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 4998] mmap(NULL, 135168, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7fcf44a46000 [pid 4998] mprotect(0x7fcf44a47000, 131072, PROT_READ|PROT_WRITE) = 0 [pid 4998] clone(child_stack=0x7fcf44a663f0, 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 5000 attached , parent_tid=[5000], tls=0x7fcf44a66700, child_tidptr=0x7fcf44a669d0) = 5000 [pid 4998] futex(0x7fcf44b5d418, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 4998] futex(0x7fcf44b5d41c, FUTEX_WAIT_PRIVATE, 0, {tv_sec=0, tv_nsec=50000000} [pid 5000] set_robust_list(0x7fcf44a669e0, 24) = 0 [pid 5000] write(4, "\x5d\x00\x00\x00\x7d\x01\x00\x00\x00\x43\x00\x00\xfe\x00\x00\x00\x00\x08\x04\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x93\x37\x89\x23\x09\x00\x00\x00\x08\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x03\x00\x2a\x7b\xca\x05\x00\x66\x64\x2f\x34\x00\x05\x00\x66\x64\x2f\x34\x00\x03\x00\x2f\x27\x2e\x05\x00\x66\x64\x2f\x34\x00\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00", 93) = 93 [pid 5000] futex(0x7fcf44b5d41c, FUTEX_WAKE_PRIVATE, 1000000) = 1 [pid 5000] futex(0x7fcf44b5d418, FUTEX_WAIT_PRIVATE, 0, NULL [pid 4998] <... futex resumed>) = 0 syzkaller login: [ 42.686414][ T4999] [ 42.688762][ T4999] ============================================ [ 42.694885][ T4999] WARNING: possible recursive locking detected [ 42.701010][ T4999] 6.4.0-syzkaller-01406-ge8f75c0270d9 #0 Not tainted [ 42.707653][ T4999] -------------------------------------------- [ 42.713781][ T4999] syz-executor149/4999 is trying to acquire lock: [ 42.720172][ T4999] ffff88807655d868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x140/0x1cc0 [ 42.728941][ T4999] [ 42.728941][ T4999] but task is already holding lock: [ 42.736277][ T4999] ffff88807655d468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x39f/0x420 [ 42.745642][ T4999] [ 42.745642][ T4999] other info that might help us debug this: [ 42.753674][ T4999] Possible unsafe locking scenario: [ 42.753674][ T4999] [ 42.761101][ T4999] CPU0 [ 42.764372][ T4999] ---- [ 42.767625][ T4999] lock(&pipe->mutex/1); [ 42.771933][ T4999] lock(&pipe->mutex/1); [ 42.776240][ T4999] [ 42.776240][ T4999] *** DEADLOCK *** [ 42.776240][ T4999] [ 42.784359][ T4999] May be due to missing lock nesting notation [ 42.784359][ T4999] [ 42.792653][ T4999] 1 lock held by syz-executor149/4999: [ 42.798086][ T4999] #0: ffff88807655d468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x39f/0x420 [ 42.807904][ T4999] [ 42.807904][ T4999] stack backtrace: [ 42.813766][ T4999] CPU: 0 PID: 4999 Comm: syz-executor149 Not tainted 6.4.0-syzkaller-01406-ge8f75c0270d9 #0 [ 42.823806][ T4999] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 [ 42.833840][ T4999] Call Trace: [ 42.837102][ T4999] [ 42.840015][ T4999] dump_stack_lvl+0xd9/0x150 [ 42.844607][ T4999] __lock_acquire+0x13eb/0x5f30 [ 42.849451][ T4999] ? print_usage_bug.part.0+0x660/0x660 [ 42.854998][ T4999] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 42.860965][ T4999] ? __lock_acquire+0x1987/0x5f30 [ 42.865975][ T4999] lock_acquire+0x1b1/0x520 [ 42.870461][ T4999] ? pipe_write+0x140/0x1cc0 [ 42.875121][ T4999] ? lock_sync+0x190/0x190 [ 42.879521][ T4999] ? __lock_acquire+0xc17/0x5f30 [ 42.884444][ T4999] __mutex_lock+0x12f/0x1350 [ 42.889023][ T4999] ? pipe_write+0x140/0x1cc0 [ 42.893598][ T4999] ? pipe_write+0x140/0x1cc0 [ 42.898170][ T4999] ? mutex_lock_io_nested+0x11a0/0x11a0 [ 42.903706][ T4999] ? find_held_lock+0x2d/0x110 [ 42.908452][ T4999] ? aa_file_perm+0x579/0x1270 [ 42.913195][ T4999] ? lock_downgrade+0x690/0x690 [ 42.918034][ T4999] pipe_write+0x140/0x1cc0 [ 42.922432][ T4999] ? aa_file_perm+0x5a3/0x1270 [ 42.927178][ T4999] ? do_proc_dopipe_max_size_conv+0x1c0/0x1c0 [ 42.933223][ T4999] ? aa_path_link+0x2f0/0x2f0 [ 42.937966][ T4999] ? mutex_lock_io_nested+0x11a0/0x11a0 [ 42.943497][ T4999] ? pipe_wait_readable+0x33a/0x420 [ 42.948765][ T4999] ? lock_downgrade+0x690/0x690 [ 42.953600][ T4999] ? _raw_spin_lock_irqsave+0x52/0x60 [ 42.958955][ T4999] do_iter_readv_writev+0x211/0x3b0 [ 42.964144][ T4999] ? generic_copy_file_range+0x1d0/0x1d0 [ 42.969767][ T4999] ? bpf_lsm_file_permission+0x9/0x10 [ 42.975123][ T4999] ? security_file_permission+0xaf/0xd0 [ 42.980657][ T4999] do_iter_write+0x182/0x810 [ 42.985227][ T4999] vfs_iter_write+0x7a/0xb0 [ 42.989710][ T4999] iter_file_splice_write+0x743/0xc80 [ 42.995151][ T4999] ? page_cache_pipe_buf_confirm+0x5b0/0x5b0 [ 43.001116][ T4999] ? bpf_lsm_file_permission+0x9/0x10 [ 43.006476][ T4999] ? security_file_permission+0xaf/0xd0 [ 43.012008][ T4999] ? page_cache_pipe_buf_confirm+0x5b0/0x5b0 [ 43.018056][ T4999] do_splice+0xb8a/0x1ec0 [ 43.022369][ T4999] ? find_held_lock+0x2d/0x110 [ 43.027223][ T4999] ? splice_file_to_pipe+0x1b0/0x1b0 [ 43.032490][ T4999] ? pipe_to_sendpage+0x390/0x390 [ 43.037506][ T4999] __do_splice+0x14e/0x270 [ 43.041903][ T4999] ? do_splice+0x1ec0/0x1ec0 [ 43.046475][ T4999] __x64_sys_splice+0x19c/0x250 [ 43.051306][ T4999] do_syscall_64+0x39/0xb0 [ 43.055705][ T4999] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 43.061582][ T4999] RIP: 0033:0x7fcf44ad5079 [ 43.066000][ T4999] 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 [pid 4999] <... splice resumed>) = -1 EXDEV (Invalid cross-device link) [pid 4999] futex(0x7fcf44b5d40c, FUTEX_WAKE_PRIVATE, 1000000) = 0 [pid 4999] futex(0x7fcf44b5d408, FUTEX_WAIT_PRIVATE, 0, NULL [pid 4998] exit_group(0) = ? [pid 5000] <... futex resumed>) = ? [pid 4999] <... futex resumed>) = ? [pid 5000] +++ exited with 0 +++ [pid 4999] +++ exited with 0 +++ +++ exited with 0 +++ [ 43.085609][ T4999] RSP: 00