syzbot


kernel BUG in mb_mark_used

Status: upstream: reported C repro on 2025/12/31 19:52
Reported-by: syzbot+7bc5ca36d6a8b7d1ef44@syzkaller.appspotmail.com
First crash: 29d, last: 14d
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 kernel BUG in mb_mark_used origin:upstream -1 C error 4 2d00h 319d 0/2 upstream: reported C repro on 2025/03/16 17:45
android-6-1 kernel BUG in mb_mark_used origin:upstream -1 C error 1 37d 326d 0/2 upstream: reported C repro on 2025/03/09 09:53
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/01/15 00:36 6m retest repro android13-5.10-lts report log

Sample crash report:
EXT4-fs (loop2): Ignoring removed nomblk_io_submit option
EXT4-fs (loop2): mounted filesystem without journal. Opts: noblock_validity,bsddf,sysvgroups,resuid=0x000000000000ee01,debug_want_extra_isize=0x0000000000000080,nodelalloc,grpid,noauto_da_alloc,nomblk_io_submit,,errors=continue
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:1640!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 387 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:mb_mark_used+0x13c4/0x13e0 fs/ext4/mballoc.c:1640
Code: 0f 0b e8 6f b7 90 ff 0f 0b e8 68 b7 90 ff 0f 0b e8 61 b7 90 ff 0f 0b e8 5a b7 90 ff 0f 0b e8 53 b7 90 ff 0f 0b e8 4c b7 90 ff <0f> 0b e8 45 b7 90 ff 0f 0b e8 3e b7 90 ff 0f 0b 66 2e 0f 1f 84 00
RSP: 0018:ffffc9000439f658 EFLAGS: 00010293
RAX: ffffffff81d2ed34 RBX: ffffc9000439f8a0 RCX: ffff8881102b0000
RDX: 0000000000000000 RSI: ffffffff80000000 RDI: 0000000000002000
RBP: ffffc9000439f730 R08: dffffc0000000000 R09: ffffed10221efe01
R10: ffffed10221efe01 R11: 1ffff110221efe00 R12: ffffffff80000000
R13: 0000000000002000 R14: ffffc9000439f8b0 R15: ffff888110f7d000
FS:  0000555569ed8500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000380 CR3: 0000000127e42000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_trim_extent fs/ext4/mballoc.c:5920 [inline]
 ext4_try_to_trim_range fs/ext4/mballoc.c:5978 [inline]
 ext4_trim_all_free fs/ext4/mballoc.c:6045 [inline]
 ext4_trim_fs+0xfbb/0x20a0 fs/ext4/mballoc.c:6136
 __ext4_ioctl fs/ext4/ioctl.c:1131 [inline]
 ext4_ioctl+0x21f1/0x3980 fs/ext4/ioctl.c:1340
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f352a1b9749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd11759d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f352a40ffa0 RCX: 00007f352a1b9749
RDX: 0000200000000080 RSI: 00000000c0185879 RDI: 0000000000000004
RBP: 00007f352a23df91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f352a40ffa0 R14: 00007f352a40ffa0 R15: 0000000000000003
Modules linked in:
---[ end trace ec27f7cc84893b44 ]---
RIP: 0010:mb_mark_used+0x13c4/0x13e0 fs/ext4/mballoc.c:1640
Code: 0f 0b e8 6f b7 90 ff 0f 0b e8 68 b7 90 ff 0f 0b e8 61 b7 90 ff 0f 0b e8 5a b7 90 ff 0f 0b e8 53 b7 90 ff 0f 0b e8 4c b7 90 ff <0f> 0b e8 45 b7 90 ff 0f 0b e8 3e b7 90 ff 0f 0b 66 2e 0f 1f 84 00
RSP: 0018:ffffc9000439f658 EFLAGS: 00010293
RAX: ffffffff81d2ed34 RBX: ffffc9000439f8a0 RCX: ffff8881102b0000
RDX: 0000000000000000 RSI: ffffffff80000000 RDI: 0000000000002000
RBP: ffffc9000439f730 R08: dffffc0000000000 R09: ffffed10221efe01
R10: ffffed10221efe01 R11: 1ffff110221efe00 R12: ffffffff80000000
R13: 0000000000002000 R14: ffffc9000439f8b0 R15: ffff888110f7d000
FS:  0000555569ed8500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000380 CR3: 0000000127e42000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/31 19:50 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 kernel BUG in mb_mark_used
* Struck through repros no longer work on HEAD.