[Android 6.1] kernel BUG in ext4_alloc_file_blocks

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1257aa4519ee UPSTREAM: tls: make sure to abort the stream ..
git tree: android14-6.1
console output: https://syzkaller.appspot.com/x/log.txt?x=14105892580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4b268c91041514a
dashboard link: https://syzkaller.appspot.com/bug?extid=8c381bcee2948a154ec6
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=11f1252f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1665eb34580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bfd6a016f71f/disk-1257aa45.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7c4a6d2d06ea/vmlinux-1257aa45.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e220a610ad4f/bzImage-1257aa45.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/cf65fb3b565c/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=16ca8dcd980000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8c381b...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:4491!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1901 Comm: syz.1.366 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:ext4_alloc_file_blocks+0xb3d/0xb40 fs/ext4/extents.c:4491
Code: 8b 4c 24 10 80 e1 07 fe c1 38 c1 0f 8c 82 f6 ff ff 48 8b 7c 24 10 e8 52 dd d0 ff e9 73 f6 ff ff e8 58 bf 09 03 e8 b3 6f 8c ff <0f> 0b 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 89 cb 41 89 d6 49
RSP: 0018:ffffc90001217b80 EFLAGS: 00010293
RAX: ffffffff81e3ae4d RBX: 0000000000000003 RCX: ffff88811012bcc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001217d00 R08: dffffc0000000000 R09: ffffed1026a200c2
R10: ffffed1026a200c2 R11: 1ffff11026a200c1 R12: ffff888135100608
R13: ffff888135100720 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f0fb7fe36c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6171979d58 CR3: 000000011fbbc000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_zero_range+0x449/0xd00 fs/ext4/extents.c:4641
ext4_fallocate+0x56a/0x1dd0 fs/ext4/extents.c:4776
vfs_fallocate+0x4c5/0x5a0 fs/open.c:324
ksys_fallocate fs/open.c:347 [inline]
__do_sys_fallocate fs/open.c:355 [inline]
__se_sys_fallocate fs/open.c:353 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:353
x64_sys_call+0x7fa/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:286
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0fb718eec9
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:00007f0fb7fe3038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f0fb73e6090 RCX: 00007f0fb718eec9
RDX: 0000000000000002 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00007f0fb7211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000007fff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0fb73e6128 R14: 00007f0fb73e6090 R15: 00007fff2d06d848
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_alloc_file_blocks+0xb3d/0xb40 fs/ext4/extents.c:4491
Code: 8b 4c 24 10 80 e1 07 fe c1 38 c1 0f 8c 82 f6 ff ff 48 8b 7c 24 10 e8 52 dd d0 ff e9 73 f6 ff ff e8 58 bf 09 03 e8 b3 6f 8c ff <0f> 0b 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 89 cb 41 89 d6 49
RSP: 0018:ffffc90001217b80 EFLAGS: 00010293
RAX: ffffffff81e3ae4d RBX: 0000000000000003 RCX: ffff88811012bcc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001217d00 R08: dffffc0000000000 R09: ffffed1026a200c2
R10: ffffed1026a200c2 R11: 1ffff11026a200c1 R12: ffff888135100608
R13: ffff888135100720 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f0fb7fe36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f831413d000 CR3: 000000011fbbc000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup