syzbot


INFO: task hung in ext4_quota_write (2)

Status: upstream: reported C repro on 2024/05/03 23:59
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+871df0871a38b9bf3ace@syzkaller.appspotmail.com
First crash: 188d, last: 35d
Bug presence (2)
Date Name Commit Repro Result
2024/07/14 linux-5.15.y (ToT) f45bea23c39c C [report] INFO: task hung in ext4_quota_write
2024/07/14 upstream (ToT) 4d145e3f830b C Didn't crash
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in ext4_quota_write origin:upstream missing-backport C done 9 77d 317d 3/3 fixed on 2024/10/08 03:39
upstream INFO: task hung in ext4_quota_write ext4 C inconclusive 22 207d 312d 25/28 fixed on 2024/06/05 13:52
linux-5.15 INFO: task hung in ext4_quota_write 2 317d 317d 0/3 auto-obsoleted due to no activity on 2024/04/05 13:59
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/10/04 00:57 14m retest repro linux-5.15.y report log
2024/10/04 00:57 14m retest repro linux-5.15.y report log
2024/10/04 00:57 14m retest repro linux-5.15.y report log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/10/02 12:24 3m fix candidate upstream error job log
2024/07/23 01:58 1m fix candidate upstream error job log

Sample crash report:
INFO: task syz-executor222:3978 blocked for more than 143 seconds.
      Not tainted 5.15.163-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor222 state:D stack:    0 pid: 3978 ppid:  3977 flags:0x00000005
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 io_schedule+0x8c/0x194 kernel/sched/core.c:8484
 bit_wait_io+0x1c/0xac kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xcc/0x1f0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x194/0x21c kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer+0x80/0xc0 fs/buffer.c:69
 lock_buffer include/linux/buffer_head.h:402 [inline]
 ext4_quota_write+0x378/0x564 fs/ext4/super.c:6581
 qtree_write_dquot+0x1dc/0x488 fs/quota/quota_tree.c:422
 v2_write_dquot+0xf4/0x188 fs/quota/quota_v2.c:358
 dquot_commit+0x14c/0x240 fs/quota/dquot.c:514
 ext4_write_dquot+0x1b4/0x314 fs/ext4/super.c:6172
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6232
 mark_dquot_dirty fs/quota/dquot.c:372 [inline]
 mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412
 dquot_alloc_inode+0x6cc/0xdb0 fs/quota/dquot.c:1800
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0x958/0x3094 fs/ext4/xattr.c:1665
 ext4_xattr_block_set+0x55c/0x2dcc fs/ext4/xattr.c:1920
 ext4_xattr_set_handle+0xb04/0x12d8 fs/ext4/xattr.c:2406
 ext4_xattr_set+0x1dc/0x350 fs/ext4/xattr.c:2507
 ext4_xattr_user_set+0xd4/0xfc fs/ext4/xattr_user.c:41
 __vfs_setxattr+0x388/0x3a4 fs/xattr.c:182
 __vfs_setxattr_noperm+0x110/0x528 fs/xattr.c:216
 __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:277
 vfs_setxattr+0x1a8/0x344 fs/xattr.c:303
 do_setxattr fs/xattr.c:588 [inline]
 setxattr+0x250/0x2b4 fs/xattr.c:611
 path_setxattr+0x17c/0x258 fs/xattr.c:630
 __do_sys_setxattr fs/xattr.c:646 [inline]
 __se_sys_setxattr fs/xattr.c:642 [inline]
 __arm64_sys_setxattr+0xbc/0xd8 fs/xattr.c:642
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014b214e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by getty/3732:
 #0: ffff0000d2a03098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001a32e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
6 locks held by syz-executor222/3978:
 #0: ffff0000ce69a460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000dbcaabd0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #1: ffff0000dbcaabd0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:302
 #2: ffff0000dbcaa8a8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000dbcaa8a8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1e0/0x12d8 fs/ext4/xattr.c:2321
 #3: ffff800014c38af8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311
 #4: ffff0000dbde60a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:507
 #5: ffff0000ce69a208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356

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


Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/24 03:05 linux-5.15.y 7c6d66f0266f e50e8da5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/07/14 22:29 linux-5.15.y f45bea23c39c eaeb5c15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/07/13 08:53 linux-5.15.y f45bea23c39c eaeb5c15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/08/29 08:34 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in ext4_quota_write
2024/08/29 08:34 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in ext4_quota_write
2024/08/29 08:34 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in ext4_quota_write
2024/08/29 07:19 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/08/29 07:11 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/08/29 07:11 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/08/29 07:06 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
2024/05/03 23:58 linux-5.15.y 284087d4f7d5 dd26401e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in ext4_quota_write
* Struck through repros no longer work on HEAD.