syzbot


kernel BUG in ext4_mb_release_inode_pa

Status: upstream: reported C repro on 2024/12/15 14:57
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+17ceeb320d1a7e75cc60@syzkaller.appspotmail.com
First crash: 6d02h, last: 6d02h
Bug presence (2)
Date Name Commit Repro Result
2024/12/17 lts (merge base) b67dc5c9ade9 C [report] kernel BUG in ext4_mb_release_inode_pa
2024/12/17 upstream (ToT) 5529876063e1 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 kernel BUG in ext4_mb_release_inode_pa C 6 14h40m 48d 0/2 upstream: reported C repro on 2024/11/03 14:27
upstream kernel BUG in ext4_mb_release_inode_pa ext4 syz unreliable error 1 396d 392d 0/28 auto-obsoleted due to no activity on 2024/02/29 10:29

Sample crash report:
EXT4-fs error (device loop3): ext4_mb_release_inode_pa:4881: group 0, free 13, pa_free 16
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:4854!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 362 Comm: syz-executor504 Not tainted 6.1.115-syzkaller-00017-g22b7ded8b55b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:ext4_mb_release_inode_pa+0xd97/0xda0 fs/ext4/mballoc.c:4854
Code: 7e ff 48 c7 c7 00 4c 2c 87 4c 89 f6 48 89 da e8 6f 5a aa 00 e9 9f f4 ff ff e8 b5 03 7e ff 0f 0b e8 0e d6 23 03 e8 a9 03 7e ff <0f> 0b 0f 1f 80 00 00 00 00 55 48 89 e5 41 57 41 56 53 49 89 fe 49
RSP: 0018:ffffc90001126a00 EFLAGS: 00010293
RAX: ffffffff81f78307 RBX: 0000000000000060 RCX: ffff8881146e8000
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90001126b50 R08: ffffffff81f7782d R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000224d58 R14: 000000000000001f R15: dffffc0000000000
FS:  00007f4d03cd36c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020020000 CR3: 0000000125119000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_mb_discard_group_preallocations+0xbe8/0xe50 fs/ext4/mballoc.c:5000
 ext4_mb_discard_preallocations fs/ext4/mballoc.c:5569 [inline]
 ext4_mb_discard_preallocations_should_retry+0x1c3/0x880 fs/ext4/mballoc.c:5590
 ext4_mb_new_blocks+0x3584/0x48a0 fs/ext4/mballoc.c:5793
 ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
 ext4_ind_map_blocks+0xfaf/0x2770 fs/ext4/indirect.c:635
 ext4_map_blocks+0x9bd/0x1ca0 fs/ext4/inode.c:680
 _ext4_get_block+0x23b/0x660 fs/ext4/inode.c:821
 ext4_get_block+0x39/0x50 fs/ext4/inode.c:838
 ext4_block_write_begin+0x55e/0x1200 fs/ext4/inode.c:1123
 ext4_write_begin+0x5e0/0xfb0
 ext4_da_write_begin+0x2ff/0x920 fs/ext4/inode.c:3000
 generic_perform_write+0x318/0x780 mm/filemap.c:3877
 ext4_buffered_write_iter+0x360/0x640 fs/ext4/file.c:285
 ext4_file_write_iter+0x194/0x1570
 call_write_iter include/linux/fs.h:2274 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0xaf6/0xed0 fs/read_write.c:584
 ksys_write+0x199/0x2c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4d03d257c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 1f 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4d03cd3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4d03dad4a8 RCX: 00007f4d03d257c9
RDX: 000000000208e24b RSI: 0000000020000240 RDI: 0000000000000006
RBP: 00007f4d03dad4a0 R08: 00007f4d03cd36c0 R09: 0000000000000000
R10: 00007f4d03cd36c0 R11: 0000000000000246 R12: 00007f4d03dad4ac
R13: 0000000000000006 R14: 00007fff74357f00 R15: 00007fff74357fe8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_mb_release_inode_pa+0xd97/0xda0 fs/ext4/mballoc.c:4854
Code: 7e ff 48 c7 c7 00 4c 2c 87 4c 89 f6 48 89 da e8 6f 5a aa 00 e9 9f f4 ff ff e8 b5 03 7e ff 0f 0b e8 0e d6 23 03 e8 a9 03 7e ff <0f> 0b 0f 1f 80 00 00 00 00 55 48 89 e5 41 57 41 56 53 49 89 fe 49
RSP: 0018:ffffc90001126a00 EFLAGS: 00010293
RAX: ffffffff81f78307 RBX: 0000000000000060 RCX: ffff8881146e8000
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90001126b50 R08: ffffffff81f7782d R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000224d58 R14: 000000000000001f R15: dffffc0000000000
FS:  00007f4d03cd36c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020020000 CR3: 0000000125119000 CR4: 00000000003506b0
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
2024/12/15 14:56 android14-6.1 22b7ded8b55b 7cbfbb3a .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-6-1 kernel BUG in ext4_mb_release_inode_pa
* Struck through repros no longer work on HEAD.