syzbot


kernel BUG in mb_mark_used

Status: upstream: reported C repro on 2025/03/16 17:45
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+111f30c98c5ace9f8e60@syzkaller.appspotmail.com
First crash: 257d, last: 8h16m
Fix bisection: failed (error log)
  
Bug presence (2)
Date Name Commit Repro Result
2025/03/18 lts (merge base) c16c81c81336 C [report] kernel BUG in mb_mark_used
2025/03/18 upstream (ToT) 81e4f8d68c66 C [report] kernel BUG in mb_mark_used
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 kernel BUG in mb_mark_used origin:upstream -1 C 1 10d 264d 0/2 upstream: reported C repro on 2025/03/09 09:53
Fix bisection attempts (7)
Created Duration User Patch Repo Result
2025/11/18 21:08 0m bisect fix android13-5.15-lts error
2025/10/17 17:49 1h00m bisect fix android13-5.15-lts OK (0) job log log
2025/09/12 03:15 3h02m bisect fix android13-5.15-lts OK (0) job log log
2025/08/03 00:23 1h43m bisect fix android13-5.15-lts OK (0) job log log
2025/07/03 09:06 2h48m bisect fix android13-5.15-lts OK (0) job log log
2025/06/02 21:41 40m bisect fix android13-5.15-lts OK (0) job log log
2025/05/01 21:01 2h11m bisect fix android13-5.15-lts OK (0) job log log

Sample crash report:
loop2: detected capacity change from 0 to 1024
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. Quota mode: none.
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:1977!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 373 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:mb_mark_used+0x14b5/0x14d0 fs/ext4/mballoc.c:1977
Code: ff ff e8 be 3d 8c ff 0f 0b e8 b7 3d 8c ff 0f 0b e8 b0 3d 8c ff 0f 0b e8 a9 3d 8c ff 0f 0b e8 a2 3d 8c ff 0f 0b e8 9b 3d 8c ff <0f> 0b e8 94 3d 8c ff 0f 0b e8 8d 3d 8c ff 0f 0b 66 2e 0f 1f 84 00
RSP: 0018:ffffc9000408f688 EFLAGS: 00010293
RAX: ffffffff81dc8145 RBX: 0000000000000008 RCX: ffff88810bd52780
RDX: 0000000000000000 RSI: ffffffff80000000 RDI: 0000000000002000
RBP: ffffc9000408f760 R08: dffffc0000000000 R09: ffffed10220b6a01
R10: ffffed10220b6a01 R11: 1ffff110220b6a00 R12: ffffffff80000000
R13: 0000000000002000 R14: ffffc9000408f830 R15: ffff8881106a8000
FS:  000055556ac04500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000380 CR3: 000000011e70a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_trim_extent fs/ext4/mballoc.c:6454 [inline]
 ext4_try_to_trim_range+0x5eb/0xff0 fs/ext4/mballoc.c:6514
 ext4_trim_all_free fs/ext4/mballoc.c:6576 [inline]
 ext4_trim_fs+0xc1b/0x1360 fs/ext4/mballoc.c:6667
 __ext4_ioctl fs/ext4/ioctl.c:1122 [inline]
 ext4_ioctl+0x1fc7/0x33c0 fs/ext4/ioctl.c:1282
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:860
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:860
 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0392633749
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:00007ffd9b21c988 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0392889fa0 RCX: 00007f0392633749
RDX: 0000200000000080 RSI: 00000000c0185879 RDI: 0000000000000004
RBP: 00007f03926b7f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0392889fa0 R14: 00007f0392889fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace d485e618d47f749f ]---
RIP: 0010:mb_mark_used+0x14b5/0x14d0 fs/ext4/mballoc.c:1977
Code: ff ff e8 be 3d 8c ff 0f 0b e8 b7 3d 8c ff 0f 0b e8 b0 3d 8c ff 0f 0b e8 a9 3d 8c ff 0f 0b e8 a2 3d 8c ff 0f 0b e8 9b 3d 8c ff <0f> 0b e8 94 3d 8c ff 0f 0b e8 8d 3d 8c ff 0f 0b 66 2e 0f 1f 84 00
RSP: 0018:ffffc9000408f688 EFLAGS: 00010293
RAX: ffffffff81dc8145 RBX: 0000000000000008 RCX: ffff88810bd52780
RDX: 0000000000000000 RSI: ffffffff80000000 RDI: 0000000000002000
RBP: ffffc9000408f760 R08: dffffc0000000000 R09: ffffed10220b6a01
R10: ffffed10220b6a01 R11: 1ffff110220b6a00 R12: ffffffff80000000
R13: 0000000000002000 R14: ffffc9000408f830 R15: ffff8881106a8000
FS:  000055556ac04500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000380 CR3: 000000011e70a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/29 00:47 android13-5.15-lts 057fdbf6d3c7 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-15 kernel BUG in mb_mark_used
2025/03/16 17:44 android13-5.15-lts 7d1f9b5c2ff5 e2826670 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2 (clean fs)] [mounted in repro #3 (clean fs)] ci2-android-5-15 kernel BUG in mb_mark_used
2025/11/29 00:02 android13-5.15-lts 057fdbf6d3c7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 kernel BUG in mb_mark_used
* Struck through repros no longer work on HEAD.