WARNING in start_this_handle

Status: upstream: reported C repro on 2026/08/17 06:22
Reported-by: syzbot+3f883e5589b65d624e3e@syzkaller.appspotmail.com
First crash: 16d, last: 15d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in start_this_handle origin:lts-only -1 syz, C error 5 59d 233d 0/3 upstream: reported C repro on 2026/01/11 16:02

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4446 at include/linux/jbd2.h:1731 jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
WARNING: CPU: 1 PID: 4446 at include/linux/jbd2.h:1731 jbd2_descriptor_blocks_per_trans fs/jbd2/transaction.c:75 [inline]
WARNING: CPU: 1 PID: 4446 at include/linux/jbd2.h:1731 jbd2_get_transaction fs/jbd2/transaction.c:112 [inline]
WARNING: CPU: 1 PID: 4446 at include/linux/jbd2.h:1731 start_this_handle+0xae4/0x125c fs/jbd2/transaction.c:411
Modules linked in:
CPU: 1 PID: 4446 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
pc : jbd2_descriptor_blocks_per_trans fs/jbd2/transaction.c:75 [inline]
pc : jbd2_get_transaction fs/jbd2/transaction.c:112 [inline]
pc : start_this_handle+0xae4/0x125c fs/jbd2/transaction.c:411
lr : jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
lr : jbd2_descriptor_blocks_per_trans fs/jbd2/transaction.c:75 [inline]
lr : jbd2_get_transaction fs/jbd2/transaction.c:112 [inline]
lr : start_this_handle+0xae4/0x125c fs/jbd2/transaction.c:411
sp : ffff8000214d7360
x29: ffff8000214d74f0 x28: 0000000010000000 x27: ffff0000d5efe764
x26: ffff70000429ae80 x25: ffff0000d5efe0b8 x24: ffff8000214d7400
x23: ffff0000d5efe7d8 x22: 1fffe0001abdfd30 x21: ffff0000d5efe100
x20: ffff0000d5efe000 x19: dfff800000000000 x18: 1fffe00033e7697e
x17: ffff80001537d000 x16: ffff8000082dd248 x15: 000000000004ffff
x14: 0000000000000001 x13: 1fffe0001c302c79 x12: 0000000000000000
x11: ff00800008ebe118 x10: 0000000000000000 x9 : ffff800008ebe118
x8 : ffff0000cc2f9c00 x7 : ffff8000083c791c x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : ffff800008ebdd3c
x2 : 0000000000000001 x1 : 0000000010000000 x0 : 0000000000000000
Call trace:
 jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
 jbd2_descriptor_blocks_per_trans fs/jbd2/transaction.c:75 [inline]
 jbd2_get_transaction fs/jbd2/transaction.c:112 [inline]
 start_this_handle+0xae4/0x125c fs/jbd2/transaction.c:411
 jbd2__journal_start+0x288/0x530 fs/jbd2/transaction.c:520
 jbd2_journal_start+0x3c/0x4c fs/jbd2/transaction.c:559
 ocfs2_start_trans+0x398/0x6f4 fs/ocfs2/journal.c:376
 ocfs2_shutdown_local_alloc+0x1a0/0x858 fs/ocfs2/localalloc.c:416
 ocfs2_dismount_volume+0x1f4/0x95c fs/ocfs2/super.c:1882
 ocfs2_put_super+0x108/0x390 fs/ocfs2/super.c:1609
 generic_shutdown_super+0x138/0x32c fs/super.c:501
 kill_block_super+0x78/0xe0 fs/super.c:1470
 deactivate_locked_super+0xb4/0x128 fs/super.c:332
 deactivate_super+0xe4/0x104 fs/super.c:363
 cleanup_mnt+0x3a8/0x430 fs/namespace.c:1191
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
 task_work_run+0x1f4/0x280 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 149722
hardirqs last  enabled at (149721): [<ffff8000083c750c>] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
hardirqs last  enabled at (149721): [<ffff8000083c750c>] timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
hardirqs last  enabled at (149721): [<ffff8000083c750c>] timekeeping_get_ns+0x120/0x3b8 kernel/time/timekeeping.c:388
hardirqs last disabled at (149722): [<ffff800011b8c2bc>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (149532): [<ffff800008031254>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (149530): [<ffff800008031220>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4446 at include/linux/jbd2.h:1731 jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
WARNING: CPU: 0 PID: 4446 at include/linux/jbd2.h:1731 jbd2_write_superblock+0x5e8/0x9c0 fs/jbd2/journal.c:1655
Modules linked in:
CPU: 0 PID: 4446 Comm: syz-executor Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
pc : jbd2_write_superblock+0x5e8/0x9c0 fs/jbd2/journal.c:1655
lr : jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
lr : jbd2_write_superblock+0x5e8/0x9c0 fs/jbd2/journal.c:1655
sp : ffff8000214d7340
x29: ffff8000214d73e0 x28: 1fffe0001c351ecb x27: dfff800000000000
x26: ffff70000429ae70 x25: ffff0000d5efe0b0 x24: ffff80001537d160
x23: 0000000010000000 x22: 1fffe0001abdfc16 x21: ffff0000d5efe980
x20: ffff0000e1a8f658 x19: ffff0000d5efe000 x18: 1fffe00033e7277e
x17: ffff80001537d000 x16: ffff800011b90080 x15: ffff800008a444b4
x14: 0000000000000001 x13: 1fffe0001c351ecb x12: 0000000000000000
x11: ff00800008ee8a20 x10: 0000000000000000 x9 : ffff800008ee8a20
x8 : ffff0000cc2f9c00 x7 : ffff800008ee71c8 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800008ee7a90
x2 : 0000000000000001 x1 : 0000000010000000 x0 : 0000000000000000
Call trace:
 jbd2_journal_has_csum_v2or3 include/linux/jbd2.h:1730 [inline]
 jbd2_write_superblock+0x5e8/0x9c0 fs/jbd2/journal.c:1655
 jbd2_journal_update_sb_log_tail+0x1b4/0x284 fs/jbd2/journal.c:1708
 __jbd2_update_log_tail+0x54/0x504 fs/jbd2/journal.c:1116
 jbd2_cleanup_journal_tail+0x168/0x1d8 fs/jbd2/checkpoint.c:364
 jbd2_log_do_checkpoint+0x21c/0xb38 fs/jbd2/checkpoint.c:315
 jbd2_journal_flush+0x1f0/0xa48 fs/jbd2/journal.c:2493
 ocfs2_journal_shutdown+0x3dc/0xbc4 fs/ocfs2/journal.c:1072
 ocfs2_dismount_volume+0x38c/0x95c fs/ocfs2/super.c:1911
 ocfs2_put_super+0x108/0x390 fs/ocfs2/super.c:1609
 generic_shutdown_super+0x138/0x32c fs/super.c:501
 kill_block_super+0x78/0xe0 fs/super.c:1470
 deactivate_locked_super+0xb4/0x128 fs/super.c:332
 deactivate_super+0xe4/0x104 fs/super.c:363
 cleanup_mnt+0x3a8/0x430 fs/namespace.c:1191
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
 task_work_run+0x1f4/0x280 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 150376
hardirqs last  enabled at (150375): [<ffff8000088f5614>] kasan_quarantine_put+0xc4/0x200 mm/kasan/quarantine.c:242
hardirqs last disabled at (150376): [<ffff800011b8c2bc>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (149780): [<ffff8000081ae3bc>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last  enabled at (149780): [<ffff8000081ae3bc>] handle_softirqs+0xb1c/0xc90 kernel/softirq.c:624
softirqs last disabled at (149725): [<ffff800008020e6c>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
ocfs2: Unmounting device (7,0) on (node local)

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/17 09:38 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2] ci2-linux-6-1-kasan-arm64 WARNING in start_this_handle
2026/08/17 08:42 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2] ci2-linux-6-1-kasan-arm64 WARNING in start_this_handle
2026/08/17 07:56 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2] ci2-linux-6-1-kasan-arm64 WARNING in start_this_handle
2026/08/17 07:14 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2] ci2-linux-6-1-kasan-arm64 WARNING in start_this_handle
2026/08/17 06:21 linux-6.1.y e4f7d8be268e 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in start_this_handle
* Struck through repros no longer work on HEAD.