kernel panic: EXT4-fs (device loop5): panic forced after error

Status: upstream: reported C repro on 2023/09/13 05:43
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+e35b543958ad678cd305@syzkaller.appspotmail.com
First crash: 1047d, last: 217d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2023/09/13 lts (merge base) aff03380bda4 C [report] kernel panic: EXT4-fs (device loop2): panic forced after error
2023/09/13 upstream (ToT) 3669558bdf35 C [report] kernel panic: EXT4-fs (device loop0): panic forced after error
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 kernel panic: EXT4-fs (device loop5): panic forced after error origin:lts 2 C error 1 111d 349d 0/2 upstream: reported C repro on 2025/08/10 15:48
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/05/15 06:05 15m retest repro android13-5.15-lts report log
2026/03/01 08:00 6m retest repro android13-5.15-lts report log
▶ ▼ Fix bisection attempts (8)
Created Duration User Patch Repo Result
2024/05/30 17:06 7m bisect fix android13-5.15-lts error job log
2024/04/27 08:18 1h27m bisect fix android13-5.15-lts OK (0) job log log
2024/03/27 08:02 48m bisect fix android13-5.15-lts OK (0) job log log
2024/02/26 04:12 33m bisect fix android13-5.15-lts OK (0) job log log
2024/01/18 01:45 46m bisect fix android13-5.15-lts OK (0) job log log
2023/12/17 18:07 1h19m bisect fix android13-5.15-lts OK (0) job log log
2023/11/17 16:18 39m bisect fix android13-5.15-lts OK (0) job log log
2023/10/17 00:16 1h01m bisect fix android13-5.15-lts OK (0) job log log

Sample crash report:
Kernel panic - not syncing: EXT4-fs (device loop5): panic forced after error
CPU: 0 PID: 295 Comm: syz-executor129 Not tainted 5.15.131-syzkaller-00653-gea586874d2f9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 dump_stack+0x15/0x17 lib/dump_stack.c:113
 panic+0x287/0x751 kernel/panic.c:309
 ext4_handle_error+0x779/0x780 fs/ext4/super.c:667
 __ext4_error+0x1ae/0x3d0 fs/ext4/super.c:756
 ext4_validate_block_bitmap+0x1075/0x1410
 ext4_wait_block_bitmap+0x1b2/0x1d0 fs/ext4/balloc.c:579
 ext4_read_block_bitmap+0x41/0x80 fs/ext4/balloc.c:591
 ext4_mb_clear_bb fs/ext4/mballoc.c:6009 [inline]
 ext4_free_blocks+0xf32/0x2ab0 fs/ext4/mballoc.c:6254
 ext4_remove_blocks fs/ext4/extents.c:2543 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2709 [inline]
 ext4_ext_remove_space+0x267c/0x4a60 fs/ext4/extents.c:2957
 ext4_ext_truncate+0x19a/0x240 fs/ext4/extents.c:4419
 ext4_truncate+0x96c/0xfa0 fs/ext4/inode.c:4269
 ext4_process_orphan+0x1d3/0x2f0 fs/ext4/orphan.c:339
 ext4_orphan_cleanup+0x909/0x1060 fs/ext4/orphan.c:474
 ext4_fill_super+0x8dc8/0x96e0 fs/ext4/super.c:4965
 mount_bdev+0x282/0x3b0 fs/super.c:1387
 ext4_mount+0x34/0x40 fs/ext4/super.c:6581
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:611
 vfs_get_tree+0x88/0x290 fs/super.c:1517
 do_new_mount+0x28b/0xad0 fs/namespace.c:2994
 path_mount+0x671/0x1070 fs/namespace.c:3324
 do_mount fs/namespace.c:3337 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3522
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3522
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f951a509bc9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe11fbbeb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f951a509bc9
RDX: 00000000200001c0 RSI: 00000000200006c0 RDI: 0000000020000640
RBP: 00000000000f4240 R08: 0000000000000000 R09: 00005555565d8378
R10: 000000003f000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe11fbbef0 R14: 00007ffe11fbbedc R15: 00007f951a55203b
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/09/13 05:42 android13-5.15-lts ea586874d2f9 59da8366 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-15 kernel panic: EXT4-fs (device loop5): panic forced after error
* Struck through repros no longer work on HEAD.