syzbot has found a reproducer for the following issue on: HEAD commit: c8c655c34e33 Merge tag 'for-linus' of git://git.kernel.org.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=12c9db44280000 kernel config: https://syzkaller.appspot.com/x/.config?x=d56ffc213bf6bf4a dashboard link: https://syzkaller.appspot.com/bug?extid=d7c9b7185ced98364b13 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=118645f8280000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17bce9d8280000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/b41434707a6f/disk-c8c655c3.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/3051545315a4/vmlinux-c8c655c3.xz kernel image: https://storage.googleapis.com/syzbot-assets/924dba1778d0/bzImage-c8c655c3.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/c6297f191793/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d7c9b7185ced98364b13@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task kworker/u4:5:2412 blocked for more than 143 seconds. Not tainted 6.3.0-syzkaller-12378-gc8c655c34e33 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:23832 pid:2412 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: <TASK> context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 queue_log_writer+0x293/0x2f0 fs/reiserfs/journal.c:2980 do_journal_begin_r+0x988/0x10e0 fs/reiserfs/journal.c:3101 journal_begin+0x166/0x400 fs/reiserfs/journal.c:3253 reiserfs_write_inode+0x1f4/0x2d0 fs/reiserfs/inode.c:1777 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x9f2/0xdb0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x54d/0xe70 fs/fs-writeback.c:1894 wb_writeback+0x294/0xa50 fs/fs-writeback.c:2068 wb_do_writeback fs/fs-writeback.c:2211 [inline] wb_workfn+0x2a5/0xfc0 fs/fs-writeback.c:2251 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> INFO: task syz-executor302:5808 blocked for more than 144 seconds. Not tainted 6.3.0-syzkaller-12378-gc8c655c34e33 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor302 state:D stack:24728 pid:5808 ppid:5003 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 bit_wait+0x16/0xe0 kernel/sched/wait_bit.c:199 __wait_on_bit+0x64/0x180 kernel/sched/wait_bit.c:49 __inode_wait_for_writeback+0x153/0x1f0 fs/fs-writeback.c:1477 inode_wait_for_writeback+0x26/0x40 fs/fs-writeback.c:1489 evict+0x2b7/0x6b0 fs/inode.c:662 iput_final fs/inode.c:1747 [inline] iput.part.0+0x50a/0x740 fs/inode.c:1773 iput+0x5c/0x80 fs/inode.c:1763 dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401 d_delete fs/dcache.c:2565 [inline] d_delete+0x16f/0x1c0 fs/dcache.c:2554 xattr_unlink+0x139/0x190 fs/reiserfs/xattr.c:97 lookup_and_delete_xattr fs/reiserfs/xattr.c:495 [inline] reiserfs_xattr_set_handle+0x7bd/0xb00 fs/reiserfs/xattr.c:530 reiserfs_xattr_set+0x454/0x5b0 fs/reiserfs/xattr.c:634 trusted_set+0xa7/0xd0 fs/reiserfs/xattr_trusted.c:31 __vfs_removexattr+0x155/0x1c0 fs/xattr.c:519 __vfs_removexattr_locked+0x1b0/0x440 fs/xattr.c:554 vfs_removexattr+0xcf/0x260 fs/xattr.c:576 ovl_do_removexattr fs/overlayfs/overlayfs.h:273 [inline] ovl_removexattr fs/overlayfs/overlayfs.h:281 [inline] ovl_make_workdir fs/overlayfs/super.c:1353 [inline] ovl_get_workdir fs/overlayfs/super.c:1436 [inline] ovl_fill_super+0x6ec5/0x7270 fs/overlayfs/super.c:1992 mount_nodev+0x64/0x120 fs/super.c:1426 legacy_get_tree+0x109/0x220 fs/fs_context.c:610 vfs_get_tree+0x8d/0x350 fs/super.c:1510 do_new_mount fs/namespace.c:3039 [inline] path_mount+0x134b/0x1e40 fs/namespace.c:3369 do_mount fs/namespace.c:3382 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x283/0x300 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6a58a51f39 RSP: 002b:00007f6a589f5208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6a58ad0768 RCX: 00007f6a58a51f39 RDX: 0000000020000080 RSI: 00000000200000c0 RDI: 0000000000000000 RBP: 00007f6a58ad0760 R08: 0000000020000480 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6a58ad076c R13: 00007ffc3484baef R14: 00007f6a589f5300 R15: 0000000000022000 </TASK> INFO: task syz-executor302:5819 blocked for more than 144 seconds. Not tainted 6.3.0-syzkaller-12378-gc8c655c34e33 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor302 state:D stack:28496 pid:5819 ppid:5003 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 wb_wait_for_completion+0x182/0x240 fs/fs-writeback.c:192 sync_inodes_sb+0x1aa/0xa60 fs/fs-writeback.c:2730 sync_filesystem.part.0+0xe6/0x1d0 fs/sync.c:64 sync_filesystem+0x8f/0xc0 fs/sync.c:43 reiserfs_remount+0x129/0x1650 fs/reiserfs/super.c:1445 legacy_reconfigure+0x119/0x180 fs/fs_context.c:633 reconfigure_super+0x40c/0xa30 fs/super.c:956 do_remount fs/namespace.c:2701 [inline] path_mount+0x1846/0x1e40 fs/namespace.c:3361 do_mount fs/namespace.c:3382 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x283/0x300 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6a58a533fa RSP: 002b:00007f6a509d4028 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6a509d46b8 RCX: 00007f6a58a533fa RDX: 00000000200001c0 RSI: 0000000020000100 RDI: 0000000000000000 RBP: 00000000ffffffff R08: 00007f6a509d40c0 R09: 0000000000000000 R10: 0000000001a484bc R11: 0000000000000286 R12: 00000000200001c0 R13: 0000000020000100 R14: 0000000000000000 R15: 00000000200004c0 </TASK> Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c798630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c798330 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c799240 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6545 2 locks held by kworker/u4:4/58: #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90001577db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 2 locks held by kworker/0:2/894: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90004cdfdb0 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 2 locks held by kworker/u4:5/2412: #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888141a53938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc9000a3a7db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 2 locks held by getty/4753: #0: ffff888027e54098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 1 lock held by syz-executor302/4997: #0: ffff88802b0620e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xd0 fs/super.c:361 2 locks held by syz-executor302/4998: #0: ffff88806f9ce0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xd0 fs/super.c:361 #1: ffffffff8c7a46b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #1: ffffffff8c7a46b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3e8/0x770 kernel/rcu/tree_exp.h:992 2 locks held by syz-executor302/5000: #0: ffff8880193da0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xd0 fs/super.c:361 #1: ffffffff8c7a46b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #1: ffffffff8c7a46b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x64a/0x770 kernel/rcu/tree_exp.h:992 1 lock held by syz-executor302/5001: #0: ffff88807704c0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xd0 fs/super.c:361 4 locks held by syz-executor302/5808: #0: ffff88807a3400e0 (&type->s_umount_key#41/1){+.+.}-{3:3}, at: alloc_super+0x22e/0xb60 fs/super.c:228 #1: ffff888076d4e460 (sb_writers#10){.+.+}-{0:0}, at: ovl_make_workdir fs/overlayfs/super.c:1282 [inline] #1: ffff888076d4e460 (sb_writers#10){.+.+}-{0:0}, at: ovl_get_workdir fs/overlayfs/super.c:1436 [inline] #1: ffff888076d4e460 (sb_writers#10){.+.+}-{0:0}, at: ovl_fill_super+0x1c5e/0x7270 fs/overlayfs/super.c:1992 #2: ffff888073b1ece0 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline] #2: ffff888073b1ece0 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: vfs_removexattr+0xbb/0x260 fs/xattr.c:575 #3: ffff888073adbe80 (&type->i_mutex_dir_key#6/3){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:810 [inline] #3: ffff888073adbe80 (&type->i_mutex_dir_key#6/3){+.+.}-{3:3}, at: lookup_and_delete_xattr fs/reiserfs/xattr.c:487 [inline] #3: ffff888073adbe80 (&type->i_mutex_dir_key#6/3){+.+.}-{3:3}, at: reiserfs_xattr_set_handle+0x72c/0xb00 fs/reiserfs/xattr.c:530 2 locks held by syz-executor302/5819: #0: ffff888076d4e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: do_remount fs/namespace.c:2698 [inline] #0: ffff888076d4e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: path_mount+0x1401/0x1e40 fs/namespace.c:3361 #1: ffff88801ee6c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff88801ee6c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x190/0xa60 fs/fs-writeback.c:2728 4 locks held by syz-executor302/6995: #0: ffff88807dc2c0e0 (&type->s_umount_key#41/1){+.+.}-{3:3}, at: alloc_super+0x22e/0xb60 fs/super.c:228 #1: ffff88807c150460 (sb_writers#10){.+.+}-{0:0}, at: ovl_make_workdir fs/overlayfs/super.c:1282 [inline] #1: ffff88807c150460 (sb_writers#10){.+.+}-{0:0}, at: ovl_get_workdir fs/overlayfs/super.c:1436 [inline] #1: ffff88807c150460 (sb_writers#10){.+.+}-{0:0}, at: ovl_fill_super+0x1c5e/0x7270 fs/overlayfs/super.c:1992 #2: ffff8880739cc520 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline] #2: ffff8880739cc520 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: vfs_removexattr+0xbb/0x260 fs/xattr.c:575 #3: ffff88807390d260 (&type->i_mutex_dir_key#6/3){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:810 [inline] #3: ffff88807390d260 (&type->i_mutex_dir_key#6/3){+.+.}-{3:3}, at: lookup_and_delete_xattr fs/reiserfs/xattr.c:487 [inline] #3: ffff88807390d260 (&type->i_mutex_dir_key#6/3){+.+.}-{3:3}, at: reiserfs_xattr_set_handle+0x72c/0xb00 fs/reiserfs/xattr.c:530 2 locks held by syz-executor302/7005: #0: ffff88807c1500e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: do_remount fs/namespace.c:2698 [inline] #0: ffff88807c1500e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: path_mount+0x1401/0x1e40 fs/namespace.c:3361 #1: ffff8881417e27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff8881417e27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x190/0xa60 fs/fs-writeback.c:2728 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-syzkaller-12378-gc8c655c34e33 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 894 Comm: kworker/0:2 Not tainted 6.3.0-syzkaller-12378-gc8c655c34e33 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: rcu_gp process_srcu RIP: 0010:do_raw_spin_lock+0x1ac/0x2b0 kernel/locking/spinlock_debug.c:118 Code: 03 65 4c 8b 24 25 c0 bb 03 00 80 3c 02 00 0f 85 e3 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 65 10 48 c7 04 03 00 00 00 00 <48> 8b 44 24 60 65 48 2b 04 25 28 00 00 00 0f 85 c6 00 00 00 48 83 RSP: 0018:ffffc90004cdfa80 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 1ffff9200099bf51 RCX: ffffffff81666574 RDX: 1ffffffff23f75a2 RSI: 0000000000000004 RDI: ffffc90004cdfaa8 RBP: ffffffff91fbad00 R08: 0000000000000001 R09: 0000000000000003 R10: fffff5200099bf55 R11: 0000000000000000 R12: ffff88801f738000 R13: ffffffff91fbad10 R14: 0000000000000000 R15: 1ffff9200099bf6a FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6a509d4718 CR3: 000000000c571000 CR4: 0000000000350ef0 Call Trace: <TASK> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x45/0x60 kernel/locking/spinlock.c:162 debug_object_activate+0x134/0x3f0 lib/debugobjects.c:690 debug_work_activate kernel/workqueue.c:517 [inline] __queue_work+0x614/0x1120 kernel/workqueue.c:1525 __queue_delayed_work+0x1c8/0x270 kernel/workqueue.c:1674 queue_delayed_work_on+0x109/0x120 kernel/workqueue.c:1710 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
