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INFO: task hung in synchronize_rcu (3)

Status: upstream: reported C repro on 2024/07/26 03:55
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+e52148e52e5075da44cc@syzkaller.appspotmail.com
First crash: 296d, last: 38d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2024/07/27 linux-5.15.y (ToT) 7c6d66f0266f C [report] INFO: task hung in ext4_quota_write
2024/07/27 upstream (ToT) 3a7e02c040b1 C Didn't crash
▶ ▼ Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in synchronize_rcu (3) C done done 374 823d 1761d 22/28 fixed on 2023/02/24 13:50
linux-6.1 INFO: task hung in synchronize_rcu origin:lts-only C unreliable 16 30d 778d 0/3 upstream: reported C repro on 2023/04/01 04:49
android-49 INFO: task hung in synchronize_rcu 1 1997d 1997d 0/3 auto-closed as invalid on 2020/03/28 16:57
linux-4.14 INFO: task hung in synchronize_rcu vfs C error 162 837d 2019d 0/1 upstream: reported C repro on 2019/11/07 04:32
linux-4.19 INFO: task hung in synchronize_rcu C error 70 827d 2017d 0/1 upstream: reported C repro on 2019/11/08 21:27
linux-5.15 INFO: task hung in synchronize_rcu 1 763d 763d 0/3 auto-obsoleted due to no activity on 2023/08/14 02:05
upstream INFO: task hung in synchronize_rcu syz done 1206 1997d 2023d 14/28 fixed on 2019/11/29 15:48
upstream INFO: task hung in synchronize_rcu (4) net fs C done error 889 8d03h 745d 0/28 upstream: reported C repro on 2023/05/04 02:01
linux-5.15 INFO: task hung in synchronize_rcu (2) 1 452d 452d 0/3 auto-obsoleted due to no activity on 2024/05/31 13:53
android-414 INFO: task hung in synchronize_rcu 1 2015d 2015d 0/1 auto-closed as invalid on 2020/03/10 10:42
upstream INFO: task hung in synchronize_rcu (2) trace 8 1996d 1996d 0/28 closed as invalid on 2019/11/30 16:54
▶ ▼ Last patch testing requests (6)
Created Duration User Patch Repo Result
2025/04/10 06:12 15m retest repro linux-5.15.y report log
2025/04/10 06:12 22m retest repro linux-5.15.y report log
2025/03/15 00:21 14m retest repro linux-5.15.y report log
2025/03/15 00:21 14m retest repro linux-5.15.y report log
2024/12/26 17:20 16m retest repro linux-5.15.y report log
2024/10/13 22:00 13m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2025/02/16 10:12 2m fix candidate upstream error job log
2024/10/15 06:09 0m fix candidate upstream error job log
2024/08/29 04:18 1m fix candidate upstream error job log

Sample crash report:
INFO: task kworker/u4:4:649 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4    state:D stack:    0 pid:  649 ppid:     2 flags:0x00000008
Workqueue: events_unbound quota_release_workfn
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 schedule_timeout+0xb8/0x344 kernel/time/timer.c:1890
 do_wait_for_common+0x214/0x388 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x4c/0x64 kernel/sched/completion.c:138
 __synchronize_srcu+0x298/0x340 kernel/rcu/srcutree.c:930
 synchronize_srcu+0x19c/0x1b4 kernel/rcu/srcutree.c:-1
 quota_release_workfn+0x12c/0x6a0 fs/quota/dquot.c:828
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
INFO: task syz-executor372:4047 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor372 state:D stack:    0 pid: 4047 ppid:  4042 flags:0x00000005
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 io_schedule+0x8c/0x194 kernel/sched/core.c:8483
 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:6582
 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:6173
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6233
 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:1801
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0x954/0x3078 fs/ext4/xattr.c:1671
 ext4_xattr_block_set+0x55c/0x2dcc fs/ext4/xattr.c:1926
 ext4_xattr_set_handle+0xb04/0x12d8 fs/ext4/xattr.c:2412
 ext4_xattr_set+0x220/0x340 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
 __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
INFO: task syz-executor372:4048 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor372 state:D stack:    0 pid: 4048 ppid:  4045 flags:0x00000005
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 io_schedule+0x8c/0x194 kernel/sched/core.c:8483
 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:6582
 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:6173
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6233
 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:1801
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0x954/0x3078 fs/ext4/xattr.c:1671
 ext4_xattr_block_set+0x55c/0x2dcc fs/ext4/xattr.c:1926
 ext4_xattr_set_handle+0xb04/0x12d8 fs/ext4/xattr.c:2412
 ext4_xattr_set+0x220/0x340 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
 __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
INFO: task syz-executor372:4049 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor372 state:D stack:    0 pid: 4049 ppid:  4044 flags:0x00000005
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 io_schedule+0x8c/0x194 kernel/sched/core.c:8483
 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:6582
 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:6173
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6233
 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:1801
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0x954/0x3078 fs/ext4/xattr.c:1671
 ext4_xattr_block_set+0x55c/0x2dcc fs/ext4/xattr.c:1926
 ext4_xattr_set_handle+0xb04/0x12d8 fs/ext4/xattr.c:2412
 ext4_xattr_set+0x220/0x340 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
 __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
INFO: task syz-executor372:4050 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor372 state:D stack:    0 pid: 4050 ppid:  4043 flags:0x00000005
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 io_schedule+0x8c/0x194 kernel/sched/core.c:8483
 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:6582
 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:6173
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6233
 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:1801
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0x954/0x3078 fs/ext4/xattr.c:1671
 ext4_xattr_block_set+0x55c/0x2dcc fs/ext4/xattr.c:1926
 ext4_xattr_set_handle+0xb04/0x12d8 fs/ext4/xattr.c:2412
 ext4_xattr_set+0x220/0x340 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
 __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
INFO: task syz-executor372:4051 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor372 state:D stack:    0 pid: 4051 ppid:  4046 flags:0x00000005
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 io_schedule+0x8c/0x194 kernel/sched/core.c:8483
 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:6582
 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:6173
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6233
 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:1801
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:883 [inline]
 ext4_xattr_set_entry+0x954/0x3078 fs/ext4/xattr.c:1671
 ext4_xattr_block_set+0x55c/0x2dcc fs/ext4/xattr.c:1926
 ext4_xattr_set_handle+0xb04/0x12d8 fs/ext4/xattr.c:2412
 ext4_xattr_set+0x220/0x340 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x4c/0x64 fs/ext4/xattr_trusted.c:38
 __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:
4 locks held by kworker/1:0/21:
1 lock held by khungtaskd/27:
 #0: ffff800014d41b60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by kworker/u4:4/649:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff800020e87c00 ((quota_release_work).work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
2 locks held by getty/3785:
 #0: ffff0000d4633098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001d6be2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
6 locks held by syz-executor372/4047:
 #0: ffff0000d76ae460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000e14083f0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000e14083f0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:302
 #2: ffff0000e14080c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000e14080c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1e0/0x12d8 fs/ext4/xattr.c:2327
 #3: ffff800014e5a5d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311
 #4: ffff0000dd7ca0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:507
 #5: ffff0000d76ae208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356
6 locks held by syz-executor372/4048:
 #0: ffff0000ceaac460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000dc3867a0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000dc3867a0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:302
 #2: ffff0000dc386478 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000dc386478 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1e0/0x12d8 fs/ext4/xattr.c:2327
 #3: ffff800014e5a5d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311
 #4: ffff0000dd7260a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:507
 #5: ffff0000ceaac208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356
6 locks held by syz-executor372/4049:
 #0: ffff0000cdbb2460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000e140a1d8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000e140a1d8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:302
 #2: ffff0000e1409eb0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000e1409eb0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1e0/0x12d8 fs/ext4/xattr.c:2327
 #3: ffff800014e5a5d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311
 #4: ffff0000dd7ca428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:507
 #5: ffff0000cdbb2208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356
6 locks held by syz-executor372/4050:
 #0: ffff0000cdd56460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000dd7683f0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000dd7683f0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:302
 #2: ffff0000dd7680c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000dd7680c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1e0/0x12d8 fs/ext4/xattr.c:2327
 #3: ffff800014e5a5d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311
 #4: ffff0000dd7ca268 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:507
 #5: ffff0000cdd56208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356
6 locks held by syz-executor372/4051:
 #0: ffff0000ce5f6460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000dd7697e0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000dd7697e0 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x17c/0x344 fs/xattr.c:302
 #2: ffff0000dd7694b8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000dd7694b8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x1e0/0x12d8 fs/ext4/xattr.c:2327
 #3: ffff800014e5a5d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311
 #4: ffff0000dd7ca5e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:507
 #5: ffff0000ce5f6208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356

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

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/27 02:36 linux-5.15.y 0c935c049b5c 20510e88 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan-arm64 INFO: task hung in synchronize_rcu
2025/03/15 15:16 linux-5.15.y 0c935c049b5c e2826670 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan-arm64 INFO: task hung in synchronize_rcu
2025/02/28 01:48 linux-5.15.y c16c81c81336 6a8fcbc4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan-arm64 INFO: task hung in synchronize_rcu
2024/07/27 03:46 linux-5.15.y 7c6d66f0266f 46eb10b7 .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 synchronize_rcu
2024/12/08 18:57 linux-5.15.y 0a51d2d4527b 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in synchronize_rcu
2024/11/05 22:10 linux-5.15.y 72244eab0dad da38b4c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in synchronize_rcu
2024/09/28 21:35 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in synchronize_rcu
2024/09/13 20:26 linux-5.15.y 3a5928702e71 b58f933c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in synchronize_rcu
2024/09/11 03:53 linux-5.15.y 14e468424d3e 8ab55d0e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: task hung in synchronize_rcu
2024/08/02 15:21 linux-5.15.y 7e89efd3ae1c 1e9c4cf3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in synchronize_rcu
2024/07/26 03:55 linux-5.15.y 7c6d66f0266f 3f86dfed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in synchronize_rcu
2024/08/30 07:35 linux-5.15.y fa93fa65db6e ee2602b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in synchronize_rcu
2024/08/29 07:07 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 synchronize_rcu
* Struck through repros no longer work on HEAD.