[Android 5.15] kernel BUG in ext4_ext_insert_index

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1edb21e89ce4 Revert "PCI/AER: Support errors introduced by..
git tree: android13-5.15-lts
console output: https://syzkaller.appspot.com/x/log.txt?x=141af614580000
kernel config: https://syzkaller.appspot.com/x/.config?x=aba6efd42433473
dashboard link: https://syzkaller.appspot.com/bug?extid=b9ae9e1fdb60be2bb2c8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=125c1258580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1375c32f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e308da3e59d7/disk-1edb21e8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0b896dbae08/vmlinux-1edb21e8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/231ef8b054bf/bzImage-1edb21e8.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/eddb5b8b8e8a/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1673de7c580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b9ae9e...@syzkaller.appspotmail.com

EXT4-fs (loop2): mounted filesystem without journal. Opts: delalloc,data_err=abort,barrier=0x0000000000000002,dioread_lock,data_err=ignore,max_dir_size_kb=0x00000000004007b1,data_err=ignore,grpquota,nobh,user_xattr,bh,dioread_nolock,,errors=continue. Quota mode: writeback.
EXT4-fs error (device loop2): ext4_mb_mark_diskspace_used:3871: comm syz.2.17: Allocating blocks 497-513 which overlap fs metadata
------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:1015!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 372 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:ext4_ext_insert_index+0x54a/0x550 fs/ext4/extents.c:1015
Code: 4c 89 fa e9 ca fd ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c dd fd ff ff 4c 89 f7 e8 d0 8e d3 ff e9 d0 fd ff ff e8 56 0e 95 ff <0f> 0b 0f 1f 40 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 81 ec
RSP: 0018:ffffc90000bf6b20 EFLAGS: 00010293
RAX: ffffffff81d3b09a RBX: ffff888129eac424 RCX: ffff88810f70e2c0
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 0000000000000000
RBP: ffffc90000bf6b90 R08: dffffc0000000000 R09: ffffed102465d62b
R10: ffffed102465d62b R11: 1ffff1102465d62a R12: 0000000000000000
R13: 00000000000000cb R14: 00000000fffffffe R15: 0000000000000054
FS: 000055557d62b500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002c000 CR3: 0000000121833000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_ext_split fs/ext4/extents.c:1275 [inline]
ext4_ext_create_new_leaf fs/ext4/extents.c:1419 [inline]
ext4_ext_insert_extent+0x3af6/0x47a0 fs/ext4/extents.c:2103
ext4_ext_map_blocks+0x18e1/0x6270 fs/ext4/extents.c:4362
ext4_map_blocks+0x97b/0x1b20 fs/ext4/inode.c:674
_ext4_get_block+0x1da/0x4e0 fs/ext4/inode.c:817
ext4_get_block_unwritten+0x2a/0x40 fs/ext4/inode.c:848
ext4_block_write_begin+0x556/0x1150 fs/ext4/inode.c:1102
ext4_write_begin+0x638/0x1220 fs/ext4/ext4_jbd2.h:-1
ext4_da_write_begin+0x2fa/0xb60 fs/ext4/inode.c:2988
generic_perform_write+0x2ad/0x670 mm/filemap.c:3870
ext4_buffered_write_iter+0x4ed/0x670 fs/ext4/file.c:270
ext4_file_write_iter+0x18c/0x1550 fs/ext4/file.c:664
call_write_iter include/linux/fs.h:2212 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x802/0xf70 fs/read_write.c:594
ksys_pwrite64 fs/read_write.c:701 [inline]
__do_sys_pwrite64 fs/read_write.c:711 [inline]
__se_sys_pwrite64 fs/read_write.c:708 [inline]
__x64_sys_pwrite64+0x191/0x220 fs/read_write.c:708
x64_sys_call+0xa6/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19
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: 0033:0x7fc64588dfc9
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:00007fff3b9294a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fc645ae4fa0 RCX: 00007fc64588dfc9
RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007fc645910f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc645ae4fa0 R14: 00007fc645ae4fa0 R15: 0000000000000004
</TASK>
Modules linked in:
---[ end trace 0a16de9a86a2f647 ]---
RIP: 0010:ext4_ext_insert_index+0x54a/0x550 fs/ext4/extents.c:1015
Code: 4c 89 fa e9 ca fd ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c dd fd ff ff 4c 89 f7 e8 d0 8e d3 ff e9 d0 fd ff ff e8 56 0e 95 ff <0f> 0b 0f 1f 40 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 81 ec
RSP: 0018:ffffc90000bf6b20 EFLAGS: 00010293
RAX: ffffffff81d3b09a RBX: ffff888129eac424 RCX: ffff88810f70e2c0
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 0000000000000000
RBP: ffffc90000bf6b90 R08: dffffc0000000000 R09: ffffed102465d62b
R10: ffffed102465d62b R11: 1ffff1102465d62a R12: 0000000000000000
R13: 00000000000000cb R14: 00000000fffffffe R15: 0000000000000054
FS: 000055557d62b500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ef1afd000 CR3: 0000000121833000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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