[Android 5.15] kernel BUG in ext4_mb_release_inode_pa

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8969ee93a483 Merge android13-5.15 into android13-5.15-lts
git tree: android13-5.15-lts
console output: https://syzkaller.appspot.com/x/log.txt?x=13c4352e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3ef8af16142b9dd4
dashboard link: https://syzkaller.appspot.com/bug?extid=a13f7e95b62ed6459ac5
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11e00456580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16b08f60580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d686db73bf84/disk-8969ee93.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6253ebf315ec/vmlinux-8969ee93.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a673b5918e79/bzImage-8969ee93.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/a7c2e4bfe489/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=16ebd67e580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/723367c506df/mount_5.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=13c496ec580000)
mounted in repro #3: https://storage.googleapis.com/syzbot-assets/f1d9e0937283/mount_8.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14eb427a580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a13f7e...@syzkaller.appspotmail.com

EXT4-fs (loop3): Remounting filesystem read-only
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:4877!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 403 Comm: syz.3.22 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_mb_release_inode_pa+0xa8e/0xa90 fs/ext4/mballoc.c:4877
Code: 80 c2 03 38 c2 0f 8c 2f fe ff ff 48 89 df 41 89 ce e8 c6 88 cb ff 44 89 f1 e9 1c fe ff ff e8 d9 0a 8c ff 0f 0b e8 d2 0a 8c ff <0f> 0b 55 48 89 e5 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc
RSP: 0018:ffffc90000be68e0 EFLAGS: 00010293
RAX: ffffffff81ddd68e RBX: 0000000000000503 RCX: ffff888113c82780
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90000be6a30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200017cd38 R12: 1ffff9200017cd34
R13: dffffc0000000000 R14: 0000000000000060 R15: ffff888120aafb28
FS: 00007f39cfcc76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555d01908 CR3: 00000001329d9000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_mb_discard_group_preallocations+0xbaa/0xdf0 fs/ext4/mballoc.c:5023
ext4_mb_discard_preallocations fs/ext4/mballoc.c:5592 [inline]
ext4_mb_discard_preallocations_should_retry+0x156/0x600 fs/ext4/mballoc.c:5613
ext4_mb_new_blocks+0x30d7/0x4220 fs/ext4/mballoc.c:5816
ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
ext4_ind_map_blocks+0xda7/0x2010 fs/ext4/indirect.c:635
ext4_map_blocks+0x926/0x1b30 fs/ext4/inode.c:678
_ext4_get_block+0x1ea/0x540 fs/ext4/inode.c:819
ext4_get_block+0x39/0x50 fs/ext4/inode.c:836
ext4_block_write_begin+0x563/0x1160 fs/ext4/inode.c:1104
ext4_write_begin+0x65a/0x12e0 fs/ext4/ext4_jbd2.h:-1
generic_perform_write+0x2b7/0x690 mm/filemap.c:3870
ext4_buffered_write_iter+0x4ed/0x670 fs/ext4/file.c:270
ext4_file_write_iter+0x440/0x1540 fs/ext4/file.c:-1
do_iter_readv_writev+0x478/0x5f0 fs/read_write.c:-1
do_iter_write+0x1fa/0x7b0 fs/read_write.c:855
vfs_writev+0x2df/0x570 fs/read_write.c:928
do_writev+0x14e/0x2c0 fs/read_write.c:971
__do_sys_writev fs/read_write.c:1044 [inline]
__se_sys_writev fs/read_write.c:1041 [inline]
__x64_sys_writev+0x7d/0x90 fs/read_write.c:1041
x64_sys_call+0x974/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:21
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: 0033:0x7f39cfe64e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f39cfcc7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f39d00ddfa0 RCX: 00007f39cfe64e59
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f39cfefad6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f39d00de038 R14: 00007f39d00ddfa0 R15: 00007ffc6250f5d8
</TASK>
Modules linked in:
---[ end trace 6b136c051d3acbf1 ]---
RIP: 0010:ext4_mb_release_inode_pa+0xa8e/0xa90 fs/ext4/mballoc.c:4877
Code: 80 c2 03 38 c2 0f 8c 2f fe ff ff 48 89 df 41 89 ce e8 c6 88 cb ff 44 89 f1 e9 1c fe ff ff e8 d9 0a 8c ff 0f 0b e8 d2 0a 8c ff <0f> 0b 55 48 89 e5 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc
RSP: 0018:ffffc90000be68e0 EFLAGS: 00010293
RAX: ffffffff81ddd68e RBX: 0000000000000503 RCX: ffff888113c82780
RDX: 0000000000000000 RSI: 0000000000000060 RDI: 0000000000000000
RBP: ffffc90000be6a30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200017cd38 R12: 1ffff9200017cd34
R13: dffffc0000000000 R14: 0000000000000060 R15: ffff888120aafb28
FS: 00007f39cfcc76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555d01908 CR3: 00000001329d9000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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