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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: 110d, last: 19d
▶ ▼ 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 (3)
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 21d 152d 0/2 upstream: reported C repro on 2024/11/03 14:27
android-5-15 kernel BUG in ext4_mb_release_inode_pa origin:lts syz 7 11d 102d 0/2 premoderation: reported syz repro on 2024/12/22 22:32
upstream kernel BUG in ext4_mb_release_inode_pa ext4 syz unreliable error 1 500d 496d 0/28 auto-obsoleted due to no activity on 2024/02/29 10:29
▶ ▼ Last patch testing requests (7)
Created Duration User Patch Repo Result
2025/03/15 22:58 11m retest repro android14-6.1 report log
2025/03/01 19:23 6m retest repro android14-6.1 report log
2025/01/31 05:22 14m retest repro android14-6.1 report log
2025/01/31 05:22 14m retest repro android14-6.1 report log
2025/01/31 05:22 10m retest repro android14-6.1 report log
2025/01/31 05:22 7m retest repro android14-6.1 report log
2024/12/31 05:52 6m retest repro android14-6.1 report log

Sample crash report:
EXT4-fs (loop0): pa ffff8881199833f0: logic 0, phys. 193, len 32
EXT4-fs error (device loop0): ext4_mb_release_inode_pa:4881: group 0, free 7, pa_free 16
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:4854!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 338 Comm: syz-executor320 Not tainted 6.1.124-syzkaller-00008-gccc915784332 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:ext4_mb_release_inode_pa+0xd97/0xda0 fs/ext4/mballoc.c:4854
Code: 7d ff 48 c7 c7 00 51 2c 87 4c 89 f6 48 89 da e8 5f 5e aa 00 e9 9f f4 ff ff e8 15 c4 7d ff 0f 0b e8 7e 3b 24 03 e8 09 c4 7d 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:ffffc90001086a00 EFLAGS: 00010293
RAX: ffffffff81f7d0b7 RBX: 0000000000000060 RCX: ffff8881113fe540
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90001086b50 R08: ffffffff81f7c5dd R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000210d58 R14: 00000000000000a0 R15: dffffc0000000000
FS:  00007fefe8ef56c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000020000 CR3: 0000000126f51000 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: 0033:0x7fefe8f46249
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 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:00007fefe8ef5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fefe8fc86e8 RCX: 00007fefe8f46249
RDX: 0000000000043451 RSI: 0000400000000200 RDI: 0000000000000007
RBP: 00007fefe8fc86e0 R08: 00007fefe8ef4f07 R09: 0000000000000000
R10: 0000000000000012 R11: 0000000000000246 R12: 00007fefe8fc86ec
R13: 000000000000000b R14: 00007fff1fdbef50 R15: 00007fff1fdbf038
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_mb_release_inode_pa+0xd97/0xda0 fs/ext4/mballoc.c:4854
Code: 7d ff 48 c7 c7 00 51 2c 87 4c 89 f6 48 89 da e8 5f 5e aa 00 e9 9f f4 ff ff e8 15 c4 7d ff 0f 0b e8 7e 3b 24 03 e8 09 c4 7d 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:ffffc90001086a00 EFLAGS: 00010293
RAX: ffffffff81f7d0b7 RBX: 0000000000000060 RCX: ffff8881113fe540
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90001086b50 R08: ffffffff81f7c5dd R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000210d58 R14: 00000000000000a0 R15: dffffc0000000000
FS:  00007fefe8ef56c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000020000 CR3: 0000000126f51000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/15 13:58 android14-6.1 ccc915784332 40a34ec9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (clean fs)] ci2-android-6-1 kernel BUG in ext4_mb_release_inode_pa
2025/01/15 10:29 android14-6.1 e09bed30088f 7315a7cf .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
2025/01/14 06:40 android14-6.1 770852bf7d99 b1f1cd88 .config strace 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
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
2025/01/17 05:15 android14-6.1 dbdf659cc65c f9e07a6e .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-android-6-1 kernel BUG in ext4_mb_release_inode_pa
2025/01/17 04:31 android14-6.1 dbdf659cc65c f9e07a6e .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-android-6-1 kernel BUG in ext4_mb_release_inode_pa
* Struck through repros no longer work on HEAD.