syzbot


INFO: task hung in ext4_quota_write

Status: upstream: reported C repro on 2023/12/27 13:51
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+d59334a63a7e339b51d1@syzkaller.appspotmail.com
First crash: 174d, last: 17d
Bug presence (3)
Date Name Commit Repro Result
2024/04/30 linux-6.1.y (ToT) dcbc050cb0d3 C [report] INFO: task hung in ext4_quota_write
2024/01/02 upstream (ToT) 610a9b8f49fb C [report] INFO: task hung in ext4_quota_write
2024/04/30 upstream (ToT) 98369dccd2f8 C Didn't crash
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in ext4_quota_write (2) 1 46d 46d 0/3 upstream: reported on 2024/05/03 23:59
upstream INFO: task hung in ext4_quota_write ext4 C inconclusive 22 64d 169d 26/27 fixed on 2024/06/05 13:52
linux-5.15 INFO: task hung in ext4_quota_write 2 174d 174d 0/3 auto-obsoleted due to no activity on 2024/04/05 13:59
Fix bisection attempts (4)
Created Duration User Patch Repo Result
2024/06/02 01:40 1h27m bisect fix linux-6.1.y job log (0) log
2024/04/19 09:44 3h11m bisect fix linux-6.1.y job log (0) log
2024/03/16 20:33 1h39m bisect fix linux-6.1.y job log (0) log
2024/02/11 18:38 1h39m bisect fix linux-6.1.y job log (0) log

Sample crash report:
INFO: task syz-executor269:3565 blocked for more than 143 seconds.
      Not tainted 6.1.70-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor269 state:D stack:20096 pid:3565  ppid:3564   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 io_schedule+0x88/0x100 kernel/sched/core.c:8786
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xcd/0x520 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 kernel/sched/wait_bit.c:117
 lock_buffer include/linux/buffer_head.h:397 [inline]
 ext4_quota_write+0x378/0x570 fs/ext4/super.c:7150
 qtree_write_dquot+0x23f/0x530 fs/quota/quota_tree.c:431
 v2_write_dquot+0x11c/0x190 fs/quota/quota_v2.c:358
 dquot_commit+0x3c0/0x510 fs/quota/dquot.c:512
 ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6753
 mark_dquot_dirty fs/quota/dquot.c:372 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:410 [inline]
 dquot_alloc_inode+0x68a/0xb50 fs/quota/dquot.c:1838
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0xb06/0x3fb0 fs/ext4/xattr.c:1665
 ext4_xattr_block_set+0x698/0x3630 fs/ext4/xattr.c:1920
 ext4_xattr_set_handle+0xdac/0x1560 fs/ext4/xattr.c:2406
 ext4_xattr_set+0x231/0x3d0 fs/ext4/xattr.c:2508
 __vfs_setxattr+0x3e7/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x21d/0x420 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x250/0x2b0 fs/xattr.c:617
 path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
 __do_sys_setxattr fs/xattr.c:652 [inline]
 __se_sys_setxattr fs/xattr.c:648 [inline]
 __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:648
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa0017f5d99
RSP: 002b:00007fff1e6eeaa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fa0017f5d99
RDX: 0000000020000380 RSI: 0000000020000340 RDI: 00000000200002c0
RBP: 00007fa00186a5f0 R08: 0000000000000000 R09: 0000555556f934c0
R10: 000000000000ffed R11: 0000000000000246 R12: 00007fff1e6eead0
R13: 00007fff1e6eecf8 R14: 431bde82d7b634db R15: 00007fa00183f03b
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12a4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12acf0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
 #0: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
 #0: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3300:
 #0: ffff88814b7b7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
6 locks held by syz-executor269/3565:
 #0: ffff88807c906460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff888074db9810 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #1: ffff888074db9810 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x1dd/0x420 fs/xattr.c:308
 #2: ffff888074db94d8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff888074db94d8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x270/0x1560 fs/ext4/xattr.c:2321
 #3: ffffffff8d270368 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
 #3: ffffffff8d270368 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline]
 #3: ffffffff8d270368 (dquot_srcu){....}-{0:0}, at: dquot_alloc_inode+0x199/0xb50 fs/quota/dquot.c:1816
 #4: ffff8880714800a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:505
 #5: ffff88807c906208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x8c/0x190 fs/quota/quota_v2.c:356

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.70-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3567 Comm: kmmpd-loop0 Not tainted 6.1.70-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:kmmpd+0x4e6/0xa70
Code: a1 0a 4c 29 eb 4c 8b bc 24 90 00 00 00 4c 89 ff 48 89 de e8 bc c1 4a ff 49 29 df 76 0f e8 d2 bf 4a ff 4c 89 ff e8 8a 93 54 08 <eb> 05 e8 c3 bf 4a ff 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 48
RSP: 0018:ffffc90003c6fda0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807a06d940
RDX: 0000000000000000 RSI: fffffffffffffffc RDI: 0000000000000000
RBP: ffffc90003c6ff00 R08: ffffffff8a946392 R09: ffffc90003c6fb40
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11003c1ee00
R13: 0000000100006858 R14: 000000000000000a R15: 00000000000001f4
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055edd6b26680 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/02 06:31 linux-6.1.y a507f147e6f0 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan INFO: task hung in ext4_quota_write
2024/01/02 01:00 linux-6.1.y a507f147e6f0 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 INFO: task hung in ext4_quota_write
2024/01/06 06:56 linux-6.1.y 38fb82ecd144 d0304e9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in ext4_quota_write
2024/01/05 22:32 linux-6.1.y 38fb82ecd144 28c42cff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in ext4_quota_write
2024/01/03 19:22 linux-6.1.y a507f147e6f0 28c42cff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in ext4_quota_write
2024/01/01 19:12 linux-6.1.y a507f147e6f0 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in ext4_quota_write
2023/12/27 15:50 linux-6.1.y 4aa6747d9352 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in ext4_quota_write
2024/01/01 19:39 linux-6.1.y a507f147e6f0 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in ext4_quota_write
2023/12/27 13:50 linux-6.1.y 4aa6747d9352 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in ext4_quota_write
* Struck through repros no longer work on HEAD.