syzbot


kernel BUG in ext4_flex_group_add

Status: premoderation: reported syz repro on 2025/04/25 02:46
Reported-by: syzbot+bcd25e3b17c60d0ba274@syzkaller.appspotmail.com
First crash: 69d, last: 51d
Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/05/12 20:37 6m retest repro android13-5.10-lts report log
2025/05/12 20:37 12m retest repro android13-5.10-lts report log

Sample crash report:
EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue
ext4 filesystem being mounted at /0/file0 supports timestamps until 2038-01-19 (0x7fffffff)
EXT4-fs (loop2): resizing filesystem from 0 to 8 blocks
------------[ cut here ]------------
kernel BUG at fs/ext4/resize.c:544!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 389 Comm: syz.2.16 Not tainted 5.10.236-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:setup_new_flex_group_blocks fs/ext4/resize.c:543 [inline]
RIP: 0010:ext4_flex_group_add+0x4827/0x4840 fs/ext4/resize.c:1499
Code: ff ff e8 fc 13 85 ff 0f 0b e8 f5 13 85 ff 0f 0b e8 ee 13 85 ff 0f 0b e8 e7 13 85 ff 0f 0b e8 e0 13 85 ff 0f 0b e8 d9 13 85 ff <0f> 0b e8 12 30 c8 02 e8 cd 13 85 ff 0f 0b 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc90002f273a0 EFLAGS: 00010293
RAX: ffffffff81e5ac17 RBX: 0000000000000001 RCX: ffff8881112093c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002f27630 R08: ffffffff81e568bb R09: 0000000000000003
R10: fffff520005e4e54 R11: dffffc0000000001 R12: 1ffff1102229a000
R13: dffffc0000000000 R14: ffff888111605400 R15: 0000000000000000
FS:  00007f06ab5ea6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f06ab5c9d58 CR3: 00000001111a7000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_resize_fs+0x38bc/0x4980 fs/ext4/resize.c:2105
 __ext4_ioctl fs/ext4/ioctl.c:1088 [inline]
 ext4_ioctl+0x2464/0x66d0 fs/ext4/ioctl.c:1334
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0x114/0x190 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: 0033:0x7f06abb79969
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:00007f06ab5ea038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f06abda0fa0 RCX: 00007f06abb79969
RDX: 0000200000000140 RSI: 0000000040086610 RDI: 0000000000000004
RBP: 00007f06abbfbab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f06abda0fa0 R15: 00007ffe17e250c8
Modules linked in:
---[ end trace 819ef6e64a6bdf6f ]---
RIP: 0010:setup_new_flex_group_blocks fs/ext4/resize.c:543 [inline]
RIP: 0010:ext4_flex_group_add+0x4827/0x4840 fs/ext4/resize.c:1499
Code: ff ff e8 fc 13 85 ff 0f 0b e8 f5 13 85 ff 0f 0b e8 ee 13 85 ff 0f 0b e8 e7 13 85 ff 0f 0b e8 e0 13 85 ff 0f 0b e8 d9 13 85 ff <0f> 0b e8 12 30 c8 02 e8 cd 13 85 ff 0f 0b 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc90002f273a0 EFLAGS: 00010293
RAX: ffffffff81e5ac17 RBX: 0000000000000001 RCX: ffff8881112093c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002f27630 R08: ffffffff81e568bb R09: 0000000000000003
R10: fffff520005e4e54 R11: dffffc0000000001 R12: 1ffff1102229a000
R13: dffffc0000000000 R14: ffff888111605400 R15: 0000000000000000
FS:  00007f06ab5ea6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f06ab5c8f98 CR3: 00000001111a7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/25 03:54 android13-5.10-lts ba8b8b193394 9882047a .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 kernel BUG in ext4_flex_group_add
2025/04/25 02:45 android13-5.10-lts ba8b8b193394 9882047a .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 kernel BUG in ext4_flex_group_add
* Struck through repros no longer work on HEAD.