kernel BUG at fs/ext4/ext4_extents.h:200!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 426 Comm: syz-executor.2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ext4_ext_mark_unwritten fs/ext4/ext4_extents.h:200 [inline]
RIP: 0010:ext4_split_extent_at+0xe68/0xe80 fs/ext4/extents.c:3203
Code: fe c1 38 c1 0f 8c de fb ff ff 48 89 df e8 a0 75 d3 ff e9 d1 fb ff ff e8 26 f3 94 ff 0f 0b e8 1f f3 94 ff 0f 0b e8 18 f3 94 ff <0f> 0b e8 11 f3 94 ff 0f 0b e8 0a f3 94 ff 0f 0b 0f 1f 84 00 00 00
RSP: 0018:ffffc9000129ef20 EFLAGS: 00010293
RAX: ffffffff81d3cc38 RBX: 0000000000000000 RCX: ffff8881120e93c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000129f090 R08: dffffc0000000000 R09: ffffed10241d0e2b
R10: ffffed10241d0e2b R11: 1ffff110241d0e2a R12: dffffc0000000000
R13: 0000000000000004 R14: 0000000000000000 R15: ffff888112309100
FS:  00007fd7c5b8b6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f61c77e2000 CR3: 0000000126244000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_split_extent+0x386/0x4e0 fs/ext4/extents.c:3385
 ext4_split_convert_extents fs/ext4/extents.c:3715 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3876 [inline]
 ext4_ext_map_blocks+0x112c/0x6270 fs/ext4/extents.c:4231
 ext4_map_blocks+0x97b/0x1b20 fs/ext4/inode.c:674
 ext4_iomap_alloc fs/ext4/inode.c:3432 [inline]
 ext4_iomap_begin+0x72a/0xa90 fs/ext4/inode.c:3482
 iomap_iter+0x57d/0xaf0 fs/iomap/iter.c:74
 __iomap_dio_rw+0xa15/0x19f0 fs/iomap/direct-io.c:597
 iomap_dio_rw+0x3e/0x90 fs/iomap/direct-io.c:684
 ext4_dio_write_iter fs/ext4/file.c:542 [inline]
 ext4_file_write_iter+0xe9d/0x1550 fs/ext4/file.c:662
 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_write+0x140/0x240 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:656
 x64_sys_call+0x8ef/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 0033:0x7fd7ce3e9959
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007fd7c5b8b0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fd7ce509050 RCX: 00007fd7ce3e9959
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007fd7ce445c88 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd7ce509050 R15: 00007fff545573e8
 </TASK>
Modules linked in:
---[ end trace d8251248197ad85d ]---
RIP: 0010:ext4_ext_mark_unwritten fs/ext4/ext4_extents.h:200 [inline]
RIP: 0010:ext4_split_extent_at+0xe68/0xe80 fs/ext4/extents.c:3203
Code: fe c1 38 c1 0f 8c de fb ff ff 48 89 df e8 a0 75 d3 ff e9 d1 fb ff ff e8 26 f3 94 ff 0f 0b e8 1f f3 94 ff 0f 0b e8 18 f3 94 ff <0f> 0b e8 11 f3 94 ff 0f 0b e8 0a f3 94 ff 0f 0b 0f 1f 84 00 00 00
RSP: 0018:ffffc9000129ef20 EFLAGS: 00010293

RAX: ffffffff81d3cc38 RBX: 0000000000000000 RCX: ffff8881120e93c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000129f090 R08: dffffc0000000000 R09: ffffed10241d0e2b
R10: ffffed10241d0e2b R11: 1ffff110241d0e2a R12: dffffc0000000000
R13: 0000000000000004 R14: 0000000000000000 R15: ffff888112309100
FS:  00007fd7c5b8b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002003f000 CR3: 0000000126244000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400