./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor1221916695 <...> DUID 00:04:e3:38:52:80:67:3f:e9:c9:a2:47:22:a3:59:23:7d:1e forked to background, child pid 4750 [ 32.901037][ T4751] 8021q: adding VLAN 0 to HW filter on device bond0 [ 32.914823][ T4751] eql: remember to turn off Van-Jacobson compression on your slave devices Starting sshd: OK syzkaller Warning: Permanently added '10.128.0.49' (ED25519) to the list of known hosts. execve("./syz-executor1221916695", ["./syz-executor1221916695"], 0x7ffeca424630 /* 10 vars */) = 0 brk(NULL) = 0x55556cbac000 brk(0x55556cbace00) = 0x55556cbace00 arch_prctl(ARCH_SET_FS, 0x55556cbac480) = 0 set_tid_address(0x55556cbac750) = 5081 set_robust_list(0x55556cbac760, 24) = 0 rseq(0x55556cbacda0, 0x20, 0, 0x53053053) = 0 prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0 readlink("/proc/self/exe", "/root/syz-executor1221916695", 4096) = 28 getrandom("\xf9\x26\xe1\x56\xd6\x6c\xf5\x91", 8, GRND_NONBLOCK) = 8 brk(NULL) = 0x55556cbace00 brk(0x55556cbcde00) = 0x55556cbcde00 brk(0x55556cbce000) = 0x55556cbce000 mprotect(0x7f4cdddd2000, 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 rt_sigaction(SIGRTMIN, {sa_handler=SIG_IGN, sa_mask=[], sa_flags=0}, NULL, 8) = 0 rt_sigaction(SIGRT_1, {sa_handler=SIG_IGN, sa_mask=[], sa_flags=0}, NULL, 8) = 0 rt_sigaction(SIGSEGV, {sa_handler=0x7f4cddd2bf50, sa_mask=[], sa_flags=SA_RESTORER|SA_NODEFER|SA_SIGINFO, sa_restorer=0x7f4cddd332c0}, NULL, 8) = 0 rt_sigaction(SIGBUS, {sa_handler=0x7f4cddd2bf50, sa_mask=[], sa_flags=SA_RESTORER|SA_NODEFER|SA_SIGINFO, sa_restorer=0x7f4cddd332c0}, executing program NULL, 8) = 0 write(1, "executing program\n", 18) = 18 mkdir("./file0", 0777) = 0 --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=NULL} --- mkdir("./file1", 000) = 0 mkdir("./bus", 000) = 0 mount(NULL, "./bus", "overlay", 0, "upperdir=./file1,workdir=./bus,lowerdir=./file0,") = 0 mkdir("./file0/file0", 000) = 0 chdir("./bus") = 0 chdir("./file0") = 0 syzkaller login: [ 56.288735][ T5081] [ 56.291082][ T5081] ============================================ [ 56.297232][ T5081] WARNING: possible recursive locking detected [ 56.303358][ T5081] 6.10.0-rc2-syzkaller-00366-g771ed66105de #0 Not tainted [ 56.310443][ T5081] -------------------------------------------- [ 56.316568][ T5081] syz-executor122/5081 is trying to acquire lock: [ 56.323050][ T5081] ffff88802f7a2420 (sb_writers#4){.+.+}-{0:0}, at: ovl_copy_up_flags+0x1110/0x4470 [ 56.332350][ T5081] [ 56.332350][ T5081] but task is already holding lock: [ 56.339735][ T5081] ffff88802f7a2420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 [ 56.348432][ T5081] [ 56.348432][ T5081] other info that might help us debug this: [ 56.356469][ T5081] Possible unsafe locking scenario: [ 56.356469][ T5081] [ 56.363896][ T5081] CPU0 [ 56.367154][ T5081] ---- [ 56.370407][ T5081] lock(sb_writers#4); [ 56.374544][ T5081] lock(sb_writers#4); [ 56.378684][ T5081] [ 56.378684][ T5081] *** DEADLOCK *** [ 56.378684][ T5081] [ 56.386818][ T5081] May be due to missing lock nesting notation [ 56.386818][ T5081] [ 56.395134][ T5081] 3 locks held by syz-executor122/5081: [ 56.400674][ T5081] #0: ffff888022d3a420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 [ 56.410503][ T5081] #1: ffff88802f7a2420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 [ 56.419637][ T5081] #2: ffff88807d238528 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_copy_up_start+0x53/0x310 [ 56.429990][ T5081] [ 56.429990][ T5081] stack backtrace: [ 56.435877][ T5081] CPU: 1 PID: 5081 Comm: syz-executor122 Not tainted 6.10.0-rc2-syzkaller-00366-g771ed66105de #0 [ 56.446466][ T5081] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 [ 56.456529][ T5081] Call Trace: [ 56.459797][ T5081] [ 56.462713][ T5081] dump_stack_lvl+0x241/0x360 [ 56.467405][ T5081] ? __pfx_dump_stack_lvl+0x10/0x10 [ 56.472598][ T5081] ? print_deadlock_bug+0x479/0x620 [ 56.477880][ T5081] validate_chain+0x15d3/0x5900 [ 56.482728][ T5081] ? mark_lock+0x9a/0x350 [ 56.487056][ T5081] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10 [ 56.493368][ T5081] ? _raw_spin_unlock_irqrestore+0x8f/0x140 [ 56.499247][ T5081] ? lockdep_hardirqs_on+0x99/0x150 [ 56.504426][ T5081] ? __pfx_validate_chain+0x10/0x10 [ 56.509660][ T5081] ? _raw_spin_unlock_irqrestore+0xdd/0x140 [ 56.515533][ T5081] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10 [ 56.521839][ T5081] ? stack_trace_save+0x118/0x1d0 [ 56.526929][ T5081] ? stack_depot_save_flags+0x6e4/0x830 [ 56.532496][ T5081] ? kasan_save_track+0x51/0x80 [ 56.537325][ T5081] ? kasan_save_track+0x3f/0x80 [ 56.542152][ T5081] ? __kasan_kmalloc+0x98/0xb0 [ 56.546892][ T5081] ? kmalloc_trace_noprof+0x19c/0x2c0 [ 56.552258][ T5081] ? ovl_encode_real_fh+0xdf/0x410 [ 56.557371][ T5081] ? ovl_copy_up_flags+0xf32/0x4470 [ 56.562565][ T5081] ? ovl_tmpfile+0x262/0x6d0 [ 56.567148][ T5081] ? vfs_tmpfile+0x396/0x510 [ 56.571725][ T5081] ? do_tmpfile+0x156/0x340 [ 56.576213][ T5081] ? path_openat+0x2ab8/0x3280 [ 56.580961][ T5081] ? do_filp_open+0x235/0x490 [ 56.585619][ T5081] ? do_sys_openat2+0x13e/0x1d0 [ 56.590452][ T5081] ? __x64_sys_open+0x225/0x270 [ 56.595286][ T5081] ? do_syscall_64+0xf3/0x230 [ 56.599945][ T5081] ? mark_lock+0x9a/0x350 [ 56.604251][ T5081] __lock_acquire+0x1346/0x1fd0 [ 56.609083][ T5081] lock_acquire+0x1ed/0x550 [ 56.613561][ T5081] ? ovl_copy_up_flags+0x1110/0x4470 [ 56.618827][ T5081] ? __pfx_lock_acquire+0x10/0x10 [ 56.623913][ T5081] ? dput+0x81/0x2b0 [ 56.627787][ T5081] ? ovl_encode_real_fh+0x26c/0x410 [ 56.632962][ T5081] ? __pfx___might_resched+0x10/0x10 [ 56.638229][ T5081] ? ovl_encode_real_fh+0x26c/0x410 [ 56.643401][ T5081] ? safesetid_security_capable+0xb2/0x1d0 [ 56.649189][ T5081] ? __pfx_ovl_encode_real_fh+0x10/0x10 [ 56.654714][ T5081] ovl_start_write+0x11d/0x290 [ 56.659456][ T5081] ? ovl_copy_up_flags+0x1110/0x4470 [ 56.664717][ T5081] ovl_copy_up_flags+0x1110/0x4470 [ 56.669816][ T5081] ? __pfx_ovl_copy_up_flags+0x10/0x10 [ 56.675254][ T5081] ? __kasan_slab_alloc+0x66/0x80 [ 56.680254][ T5081] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 56.686299][ T5081] ? mark_lock+0x9a/0x350 [ 56.690608][ T5081] ? __lock_acquire+0x1346/0x1fd0 [ 56.695629][ T5081] ? from_vfsgid+0x6b/0x90 [ 56.700041][ T5081] ? inode_init_owner+0x1d2/0x360 [ 56.705066][ T5081] ovl_tmpfile+0x262/0x6d0 [ 56.709478][ T5081] ? __pfx_ovl_tmpfile+0x10/0x10 [ 56.714403][ T5081] ? _raw_spin_unlock+0x28/0x50 [ 56.719235][ T5081] ? d_alloc+0x142/0x190 [ 56.723456][ T5081] ? mode_strip_sgid+0xa1/0x1a0 [ 56.728288][ T5081] vfs_tmpfile+0x396/0x510 [ 56.732689][ T5081] do_tmpfile+0x156/0x340 [ 56.737002][ T5081] ? __pfx_do_tmpfile+0x10/0x10 [ 56.741854][ T5081] ? init_file+0x15c/0x200 [ 56.746273][ T5081] path_openat+0x2ab8/0x3280 [ 56.750854][ T5081] ? _raw_spin_unlock_irqrestore+0xdd/0x140 [ 56.756733][ T5081] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10 [ 56.763042][ T5081] ? mark_lock+0x9a/0x350 [ 56.767356][ T5081] ? __lock_acquire+0x1346/0x1fd0 [ 56.772361][ T5081] ? mark_lock+0x9a/0x350 [ 56.776669][ T5081] ? __lock_acquire+0x1346/0x1fd0 [ 56.781689][ T5081] ? __pfx_path_openat+0x10/0x10 [ 56.786612][ T5081] do_filp_open+0x235/0x490 [ 56.791098][ T5081] ? __pfx_do_filp_open+0x10/0x10 [ 56.796109][ T5081] ? _raw_spin_unlock+0x28/0x50 [ 56.800941][ T5081] ? alloc_fd+0x59d/0x640 [ 56.805250][ T5081] do_sys_openat2+0x13e/0x1d0 [ 56.809906][ T5081] ? __pfx_do_sys_openat2+0x10/0x10 [ 56.815103][ T5081] ? lockdep_hardirqs_on+0x99/0x150 [ 56.820306][ T5081] ? _raw_spin_unlock_irq+0x2e/0x50 [ 56.825564][ T5081] ? ptrace_notify+0x279/0x380 [ 56.830341][ T5081] __x64_sys_open+0x225/0x270 [ 56.835006][ T5081] ? __pfx___x64_sys_open+0x10/0x10 [ 56.840189][ T5081] ? do_syscall_64+0x100/0x230 [ 56.844938][ T5081] do_syscall_64+0xf3/0x230 [ 56.849444][ T5081] ? clear_bhb_loop+0x35/0x90 [ 56.854101][ T5081] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 56.860032][ T5081] RIP: 0033:0x7f4cddd5ef49 [ 56.864437][ T5081] Code: 48 83 c4 28 c3 e8 67 17 00 00 0f 1f 80 00 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 open(".", O_RDWR|O_SYNC|O_CLOEXEC|O_TMPFILE, 000) = 3 exit_group(0) = ? +++ exited with 0 +++ [ 56.884042][ T5081] RSP: 002b:00007ffc02708338 EFLAGS: 00000246 ORIG_RAX: 000000000