./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor3767933669 <...> DUID 00:04:a1:af:59:a1:d1:b4:3c:07:ca:f1:84:99:36:26:44:c7 forked to background, child pid 4665 [ 20.900699][ T4666] 8021q: adding VLAN 0 to HW filter on device bond0 [ 20.910565][ T4666] eql: remember to turn off Van-Jacobson compression on your slave devices Starting sshd: OK syzkaller Warning: Permanently added '10.128.0.134' (ECDSA) to the list of known hosts. execve("./syz-executor3767933669", ["./syz-executor3767933669"], 0x7ffe7dc92530 /* 10 vars */) = 0 brk(NULL) = 0x5555569aa000 brk(0x5555569aac40) = 0x5555569aac40 arch_prctl(ARCH_SET_FS, 0x5555569aa300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 readlink("/proc/self/exe", "/root/syz-executor3767933669", 4096) = 28 brk(0x5555569cbc40) = 0x5555569cbc40 brk(0x5555569cc000) = 0x5555569cc000 mprotect(0x7f496d01e000, 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 unshare(CLONE_NEWPID) = 0 clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD./strace-static-x86_64: Process 4998 attached , child_tidptr=0x5555569aa5d0) = 4998 [pid 4998] mount(NULL, "/sys/fs/fuse/connections", "fusectl", 0, NULL) = -1 EBUSY (Device or resource busy) [pid 4998] prctl(PR_SET_PDEATHSIG, SIGKILL) = 0 [pid 4998] setsid() = 1 [pid 4998] prlimit64(0, RLIMIT_AS, {rlim_cur=204800*1024, rlim_max=204800*1024}, NULL) = 0 [pid 4998] prlimit64(0, RLIMIT_MEMLOCK, {rlim_cur=32768*1024, rlim_max=32768*1024}, NULL) = 0 [pid 4998] prlimit64(0, RLIMIT_FSIZE, {rlim_cur=139264*1024, rlim_max=139264*1024}, NULL) = 0 [pid 4998] prlimit64(0, RLIMIT_STACK, {rlim_cur=1024*1024, rlim_max=1024*1024}, NULL) = 0 [pid 4998] prlimit64(0, RLIMIT_CORE, {rlim_cur=131072*1024, rlim_max=131072*1024}, NULL) = 0 [pid 4998] prlimit64(0, RLIMIT_NOFILE, {rlim_cur=256, rlim_max=256}, NULL) = 0 [pid 4998] unshare(CLONE_NEWNS) = 0 [pid 4998] mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) = 0 [pid 4998] unshare(CLONE_NEWIPC) = 0 [pid 4998] unshare(CLONE_NEWCGROUP) = 0 [pid 4998] unshare(CLONE_NEWUTS) = 0 [pid 4998] unshare(CLONE_SYSVSEM) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/shmmax", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "16777216", 8) = 8 [pid 4998] close(3) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/shmall", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "536870912", 9) = 9 [pid 4998] close(3) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/shmmni", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "1024", 4) = 4 [pid 4998] close(3) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/msgmax", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "8192", 4) = 4 [pid 4998] close(3) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/msgmni", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "1024", 4) = 4 [pid 4998] close(3) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/msgmnb", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "1024", 4) = 4 [pid 4998] close(3) = 0 [pid 4998] openat(AT_FDCWD, "/proc/sys/kernel/sem", O_WRONLY|O_CLOEXEC) = 3 [pid 4998] write(3, "1024 1048576 500 1024", 21) = 21 [pid 4998] close(3) = 0 [pid 4998] getpid() = 1 [pid 4998] capget({version=_LINUX_CAPABILITY_VERSION_3, pid=1}, {effective=1<tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x174/0x230 [ 41.819132][ T10] [ 41.819132][ T10] but task is already holding lock: [ 41.826467][ T10] ffff88807636c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x174/0x230 [ 41.836089][ T10] [ 41.836089][ T10] other info that might help us debug this: [ 41.844116][ T10] Possible unsafe locking scenario: [ 41.844116][ T10] [ 41.851543][ T10] CPU0 [ 41.854796][ T10] ---- [ 41.858137][ T10] lock(&tree->tree_lock/1); [ 41.862787][ T10] lock(&tree->tree_lock/1); [ 41.867530][ T10] [ 41.867530][ T10] *** DEADLOCK *** [ 41.867530][ T10] [ 41.875654][ T10] May be due to missing lock nesting notation [ 41.875654][ T10] [ 41.883951][ T10] 5 locks held by kworker/u4:0/10: [ 41.889042][ T10] #0: ffff888144a6e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 [ 41.899644][ T10] #1: ffffc900000f7db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 [ 41.911461][ T10] #2: ffff88807e578108 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_ext_write_extent+0x82/0x200 [ 41.922060][ T10] #3: ffff88807636c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x174/0x230 [ 41.932143][ T10] #4: ffff888075a50108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1bf/0xf90 [ 41.943519][ T10] [ 41.943519][ T10] stack backtrace: [ 41.949388][ T10] CPU: 1 PID: 10 Comm: kworker/u4:0 Not tainted 6.4.0-rc6-syzkaller-00006-gfd37b884003c #0 [ 41.959348][ T10] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 [ 41.969389][ T10] Workqueue: writeback wb_workfn (flush-7:0) [ 41.975365][ T10] Call Trace: [ 41.978626][ T10] [ 41.981544][ T10] dump_stack_lvl+0xd9/0x150 [ 41.986124][ T10] __lock_acquire+0x13eb/0x5f30 [ 41.990972][ T10] ? lockdep_hardirqs_on+0x7d/0x100 [ 41.996157][ T10] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 42.002127][ T10] ? __stack_depot_save+0x23b/0x510 [ 42.007317][ T10] lock_acquire+0x1b1/0x520 [ 42.011807][ T10] ? hfsplus_find_init+0x174/0x230 [ 42.016907][ T10] ? lock_sync+0x190/0x190 [ 42.021308][ T10] ? wb_writeback+0x294/0xa50 [ 42.025976][ T10] ? wb_workfn+0x2a5/0xfc0 [ 42.030383][ T10] __mutex_lock+0x12f/0x1350 [ 42.034960][ T10] ? hfsplus_find_init+0x174/0x230 [ 42.040062][ T10] ? __kmem_cache_alloc_node+0x48/0x320 [ 42.045595][ T10] ? hfsplus_find_init+0x174/0x230 [ 42.050698][ T10] ? mutex_lock_io_nested+0x11a0/0x11a0 [ 42.056232][ T10] ? __kmem_cache_alloc_node+0x1b0/0x320 [ 42.061853][ T10] ? hfsplus_find_init+0x95/0x230 [ 42.066869][ T10] ? rcu_is_watching+0x12/0xb0 [ 42.071626][ T10] hfsplus_find_init+0x174/0x230 [ 42.076554][ T10] hfsplus_ext_read_extent+0x185/0xae0 [ 42.081997][ T10] ? mutex_lock_io_nested+0x11a0/0x11a0 [ 42.087532][ T10] ? _raw_spin_unlock+0x28/0x40 [ 42.092371][ T10] ? hfsplus_free_extents+0x510/0x510 [ 42.097731][ T10] ? hfsplus_block_allocate+0x7e/0x8c0 [ 42.103179][ T10] ? rcu_is_watching+0x12/0xb0 [ 42.107936][ T10] ? __mark_inode_dirty+0x297/0xd60 [ 42.113123][ T10] hfsplus_file_extend+0x684/0xf90 [ 42.118241][ T10] ? hfsplus_free_fork+0x7d0/0x7d0 [ 42.123339][ T10] ? __mutex_lock+0x231/0x1350 [ 42.128088][ T10] ? hfsplus_find_init+0x174/0x230 [ 42.133206][ T10] ? hfsplus_brec_find+0x3ee/0x520 [ 42.138305][ T10] ? hfsplus_brec_remove+0x4f0/0x4f0 [ 42.143579][ T10] hfsplus_bmap_reserve+0x31c/0x410 [ 42.148769][ T10] __hfsplus_ext_write_extent+0x44b/0x5b0 [ 42.154478][ T10] hfsplus_ext_write_extent+0x1ba/0x200 [ 42.160009][ T10] ? hfsplus_ext_cmp_key+0x300/0x300 [ 42.165281][ T10] ? __writeback_single_inode+0x2e4/0xdb0 [ 42.170993][ T10] ? lock_downgrade+0x690/0x690 [ 42.175835][ T10] ? do_raw_spin_lock+0x124/0x2b0 [ 42.180851][ T10] hfsplus_write_inode+0x22/0x520 [ 42.185861][ T10] __writeback_single_inode+0x9f2/0xdb0 [ 42.191399][ T10] writeback_sb_inodes+0x54d/0xe70 [ 42.196501][ T10] ? sync_inode_metadata+0xe0/0xe0 [ 42.201606][ T10] ? rcu_is_watching+0x12/0xb0 [ 42.206360][ T10] ? queue_io+0x386/0x4e0 [ 42.210678][ T10] wb_writeback+0x294/0xa50 [ 42.215169][ T10] ? __writeback_inodes_wb+0x280/0x280 [ 42.220614][ T10] ? lock_downgrade+0x690/0x690 [ 42.225452][ T10] ? mark_held_locks+0x9f/0xe0 [ 42.230206][ T10] ? _raw_spin_unlock_irq+0x23/0x50 [ 42.235393][ T10] wb_workfn+0x2a5/0xfc0 [ 42.239641][ T10] ? inode_wait_for_writeback+0x40/0x40 [ 42.245178][ T10] ? lock_sync+0x190/0x190 [ 42.249582][ T10] ? lock_downgrade+0x690/0x690 [ 42.254421][ T10] ? _raw_spin_unlock_irq+0x23/0x50 [ 42.259609][ T10] process_one_work+0x99a/0x15e0 [ 42.264539][ T10] ? pwq_dec_nr_in_flight+0x2a0/0x2a0 [ 42.269899][ T10] ? spin_bug+0x1c0/0x1c0 [ 42.274215][ T10] ? _raw_spin_lock_irq+0x45/0x50 [ 42.279230][ T10] worker_thread+0x67d/0x10c0 [ 42.283911][ T10] ? process_one_work+0x15e0/0x15e0 [ 42.289097][ T10] kthread+0x344/0x440 [ 42.293164][ T10] ? kthread_complete_and_exit+0x40/0x40 [ 42.298784][ T10] ret_from_fork+0x1f/0x30 [ 42.303194][ T10]