./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor708859103 <...> DUID 00:04:53:46:a9:9d:03:7a:46:b2:48:ff:4a:ea:3f:46:f2:43 forked to background, child pid 4670 [ 49.314449][ T4671] 8021q: adding VLAN 0 to HW filter on device bond0 [ 49.335187][ T4671] eql: remember to turn off Van-Jacobson compression on your slave devices Starting sshd: OK syzkaller Warning: Permanently added '10.128.1.188' (ECDSA) to the list of known hosts. execve("./syz-executor708859103", ["./syz-executor708859103"], 0x7ffde6394160 /* 10 vars */) = 0 brk(NULL) = 0x555555d1e000 brk(0x555555d1ec40) = 0x555555d1ec40 arch_prctl(ARCH_SET_FS, 0x555555d1e300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 readlink("/proc/self/exe", "/root/syz-executor708859103", 4096) = 27 brk(0x555555d3fc40) = 0x555555d3fc40 brk(0x555555d40000) = 0x555555d40000 mprotect(0x7fc96e54a000, 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, child_tidptr=0x555555d1e5d0) = 5007 ./strace-static-x86_64: Process 5007 attached [pid 5007] mount(NULL, "/sys/fs/fuse/connections", "fusectl", 0, NULL) = -1 EBUSY (Device or resource busy) [pid 5007] prctl(PR_SET_PDEATHSIG, SIGKILL) = 0 [pid 5007] setsid() = 1 [pid 5007] prlimit64(0, RLIMIT_AS, {rlim_cur=204800*1024, rlim_max=204800*1024}, NULL) = 0 [pid 5007] prlimit64(0, RLIMIT_MEMLOCK, {rlim_cur=32768*1024, rlim_max=32768*1024}, NULL) = 0 [pid 5007] prlimit64(0, RLIMIT_FSIZE, {rlim_cur=139264*1024, rlim_max=139264*1024}, NULL) = 0 [pid 5007] prlimit64(0, RLIMIT_STACK, {rlim_cur=1024*1024, rlim_max=1024*1024}, NULL) = 0 [pid 5007] prlimit64(0, RLIMIT_CORE, {rlim_cur=131072*1024, rlim_max=131072*1024}, NULL) = 0 [pid 5007] prlimit64(0, RLIMIT_NOFILE, {rlim_cur=256, rlim_max=256}, NULL) = 0 [pid 5007] unshare(CLONE_NEWNS) = 0 [pid 5007] mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) = 0 [pid 5007] unshare(CLONE_NEWIPC) = 0 [pid 5007] unshare(CLONE_NEWCGROUP) = 0 [pid 5007] unshare(CLONE_NEWUTS) = 0 [pid 5007] unshare(CLONE_SYSVSEM) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/shmmax", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "16777216", 8) = 8 [pid 5007] close(3) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/shmall", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "536870912", 9) = 9 [pid 5007] close(3) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/shmmni", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "1024", 4) = 4 [pid 5007] close(3) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/msgmax", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "8192", 4) = 4 [pid 5007] close(3) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/msgmni", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "1024", 4) = 4 [pid 5007] close(3) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/msgmnb", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "1024", 4) = 4 [pid 5007] close(3) = 0 [pid 5007] openat(AT_FDCWD, "/proc/sys/kernel/sem", O_WRONLY|O_CLOEXEC) = 3 [pid 5007] write(3, "1024 1048576 500 1024", 21) = 21 [pid 5007] close(3) = 0 [pid 5007] getpid() = 1 [pid 5007] capget({version=_LINUX_CAPABILITY_VERSION_3, pid=1}, {effective=1<tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x182/0x240 [ 78.989352][ T10] [ 78.989352][ T10] but task is already holding lock: [ 78.996728][ T10] ffff888079bd20b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x182/0x240 [ 79.006100][ T10] [ 79.006100][ T10] other info that might help us debug this: [ 79.014170][ T10] Possible unsafe locking scenario: [ 79.014170][ T10] [ 79.021655][ T10] CPU0 [ 79.024958][ T10] ---- [ 79.028240][ T10] lock(&tree->tree_lock/1); [ 79.033051][ T10] lock(&tree->tree_lock/1); [ 79.037755][ T10] [ 79.037755][ T10] *** DEADLOCK *** [ 79.037755][ T10] [ 79.045991][ T10] May be due to missing lock nesting notation [ 79.045991][ T10] [ 79.054317][ T10] 4 locks held by kworker/u4:0/10: [ 79.059598][ T10] #0: ffff888145a7d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 [ 79.070281][ T10] #1: ffffc900000f7db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 [ 79.082438][ T10] #2: ffff888079bd20b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x182/0x240 [ 79.092227][ T10] #3: ffff8880790400f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0x97/0xae0 [ 79.103400][ T10] [ 79.103400][ T10] stack backtrace: [ 79.109292][ T10] CPU: 0 PID: 10 Comm: kworker/u4:0 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 [ 79.118773][ T10] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 [ 79.128942][ T10] Workqueue: writeback wb_workfn (flush-7:0) [ 79.134967][ T10] Call Trace: [ 79.138258][ T10] [ 79.141197][ T10] dump_stack_lvl+0xd9/0x150 [ 79.145834][ T10] __lock_acquire+0x13eb/0x5f30 [ 79.150841][ T10] ? lockdep_hardirqs_on+0x7d/0x100 [ 79.156086][ T10] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 79.162117][ T10] ? __stack_depot_save+0x23b/0x510 [ 79.167365][ T10] lock_acquire.part.0+0x11c/0x370 [ 79.172528][ T10] ? hfs_find_init+0x182/0x240 [ 79.177327][ T10] ? lock_sync+0x190/0x190 [ 79.181775][ T10] ? rcu_is_watching+0x12/0xb0 [ 79.186555][ T10] ? trace_lock_acquire+0x12d/0x180 [ 79.191774][ T10] ? hfs_find_init+0x182/0x240 [ 79.196555][ T10] ? lock_acquire+0x32/0xc0 [ 79.201078][ T10] ? hfs_find_init+0x182/0x240 [ 79.205860][ T10] __mutex_lock+0x12f/0x1350 [ 79.210465][ T10] ? hfs_find_init+0x182/0x240 [ 79.215252][ T10] ? __kmem_cache_alloc_node+0x48/0x320 [ 79.220824][ T10] ? hfs_find_init+0x182/0x240 [ 79.225627][ T10] ? mutex_lock_io_nested+0x11a0/0x11a0 [ 79.231194][ T10] ? __kmem_cache_alloc_node+0x1b0/0x320 [ 79.236857][ T10] ? hfs_find_init+0x95/0x240 [ 79.241563][ T10] ? rcu_is_watching+0x12/0xb0 [ 79.248193][ T10] hfs_find_init+0x182/0x240 [ 79.252829][ T10] hfs_ext_read_extent+0x18d/0xa20 [ 79.257972][ T10] ? mutex_lock_io_nested+0x11a0/0x11a0 [ 79.263567][ T10] ? hfs_free_extents+0x2e0/0x2e0 [ 79.268612][ T10] ? hfs_mark_mdb_dirty+0x9d/0x200 [ 79.273749][ T10] ? do_raw_spin_unlock+0x175/0x230 [ 79.278977][ T10] ? _raw_spin_unlock+0x28/0x40 [ 79.283851][ T10] hfs_extend_file+0x4b5/0xae0 [ 79.288638][ T10] ? hfs_free_fork+0x920/0x920 [ 79.293435][ T10] ? hfs_brec_find+0x3c9/0x500 [ 79.298223][ T10] hfs_bmap_reserve+0x29f/0x380 [ 79.303095][ T10] __hfs_ext_write_extent+0x3c1/0x510 [ 79.308504][ T10] hfs_ext_write_extent+0x1a6/0x1f0 [ 79.313817][ T10] ? hfs_ext_keycmp+0x310/0x310 [ 79.318691][ T10] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 79.324696][ T10] ? lock_downgrade+0x690/0x690 [ 79.329580][ T10] hfs_write_inode+0x95/0x9d0 [ 79.334280][ T10] ? hfs_inode_write_fork+0x1c0/0x1c0 [ 79.339761][ T10] ? find_held_lock+0x2d/0x110 [ 79.344566][ T10] ? __writeback_single_inode+0x2e4/0xdb0 [ 79.350306][ T10] ? lock_downgrade+0x690/0x690 [ 79.355193][ T10] ? do_raw_spin_lock+0x124/0x2b0 [ 79.360265][ T10] ? spin_bug+0x1c0/0x1c0 [ 79.364656][ T10] ? lock_acquire+0x32/0xc0 [ 79.369191][ T10] ? __writeback_single_inode+0x255/0xdb0 [ 79.374946][ T10] __writeback_single_inode+0x9f2/0xdb0 [ 79.380524][ T10] writeback_sb_inodes+0x54d/0xe70 [ 79.385661][ T10] ? sync_inode_metadata+0xe0/0xe0 [ 79.390788][ T10] ? rcu_is_watching+0x12/0xb0 [ 79.395564][ T10] ? queue_io+0x386/0x4e0 [ 79.399918][ T10] wb_writeback+0x155/0xa40 [ 79.404438][ T10] ? __writeback_inodes_wb+0x280/0x280 [ 79.409905][ T10] ? lock_downgrade+0x690/0x690 [ 79.414796][ T10] ? mark_held_locks+0x9f/0xe0 [ 79.419605][ T10] ? _raw_spin_unlock_irq+0x23/0x50 [ 79.424867][ T10] wb_workfn+0x2a5/0xcc0 [ 79.429227][ T10] ? lock_acquire+0x32/0xc0 [ 79.433890][ T10] ? inode_wait_for_writeback+0x40/0x40 [ 79.439469][ T10] ? lock_sync+0x190/0x190 [ 79.443921][ T10] ? rcu_is_watching+0x12/0xb0 [ 79.448700][ T10] ? trace_lock_acquire+0x12d/0x180 [ 79.453921][ T10] ? process_one_work+0x8b7/0x15e0 [ 79.459056][ T10] ? lock_acquire+0x32/0xc0 [ 79.463580][ T10] ? process_one_work+0x8b7/0x15e0 [ 79.468816][ T10] process_one_work+0x99a/0x15e0 [ 79.473788][ T10] ? pwq_dec_nr_in_flight+0x2a0/0x2a0 [ 79.479213][ T10] ? spin_bug+0x1c0/0x1c0 [ 79.483577][ T10] ? lock_acquire+0x32/0xc0 [ 79.488102][ T10] ? worker_thread+0x16d/0x10c0 [ 79.492981][ T10] worker_thread+0x67d/0x10c0 [ 79.497686][ T10] ? process_one_work+0x15e0/0x15e0 [ 79.502909][ T10] kthread+0x344/0x440 [ 79.507004][ T10] ? kthread_complete_and_exit+0x40/0x40 [ 79.512672][ T10] ret_from_fork+0x1f/0x30 [ 79.517142][ T10]