syzbot

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kernel BUG at fs/ext4/extents.c:3186!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 481 Comm: syz.0.34 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_split_extent_at+0xe22/0xe40 fs/ext4/extents.c:3186
Code: ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c fc fb ff ff 4c 89 f7 49 89 d7 e8 bb e4 d2 ff 4c 89 fa e9 e9 fb ff ff e8 7e b6 93 ff <0f> 0b e8 77 b6 93 ff 0f 0b e8 70 b6 93 ff 0f 0b e8 69 b6 93 ff 0f
RSP: 0018:ffffc90001026d00 EFLAGS: 00010293
RAX: ffffffff81d61682 RBX: 0000000000000007 RCX: ffff8881192e93c0
RDX: 0000000000000000 RSI: 0000000000000018 RDI: 000000000000008e
RBP: ffffc90001026e78 R08: 0000000000000010 R09: 000000000000043b
R10: dffffc0000000000 R11: ffffed10235c802a R12: dffffc0000000000
R13: 000000000000008e R14: 0000000000000030 R15: 0000000000000010
FS:  00007f27f060f6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b759cb000 CR3: 000000012e1e1000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_split_extent+0x363/0x4c0 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+0x10e5/0x61e0 fs/ext4/extents.c:4231
 ext4_map_blocks+0x988/0x1b30 fs/ext4/inode.c:674
 mpage_map_one_extent fs/ext4/inode.c:2421 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline]
 ext4_writepages+0x123f/0x3090 fs/ext4/inode.c:2842
 do_writepages+0x473/0x6c0 mm/page-writeback.c:2388
 filemap_fdatawrite_wbc+0x1f4/0x250 mm/filemap.c:409
 __filemap_fdatawrite_range mm/filemap.c:442 [inline]
 file_write_and_wait_range+0x14d/0x220 mm/filemap.c:819
 ext4_sync_file+0x1a9/0xa10 fs/ext4/fsync.c:151
 vfs_fsync_range+0x190/0x1a0 fs/sync.c:188
 generic_write_sync include/linux/fs.h:3038 [inline]
 ext4_buffered_write_iter+0x5d0/0x670 fs/ext4/file.c:277
 ext4_file_write_iter+0x440/0x1540 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2212 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x835/0xfd0 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+0x197/0x220 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: 0033:0x7f27f07ac799
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:00007f27f060f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f27f0a25fa0 RCX: 00007f27f07ac799
RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007f27f0842bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f27f0a26038 R14: 00007f27f0a25fa0 R15: 00007ffdb1914d28
 </TASK>
Modules linked in:
---[ end trace 8bdda494f1333f8f ]---
RIP: 0010:ext4_split_extent_at+0xe22/0xe40 fs/ext4/extents.c:3186
Code: ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c fc fb ff ff 4c 89 f7 49 89 d7 e8 bb e4 d2 ff 4c 89 fa e9 e9 fb ff ff e8 7e b6 93 ff <0f> 0b e8 77 b6 93 ff 0f 0b e8 70 b6 93 ff 0f 0b e8 69 b6 93 ff 0f
RSP: 0018:ffffc90001026d00 EFLAGS: 00010293
RAX: ffffffff81d61682 RBX: 0000000000000007 RCX: ffff8881192e93c0
RDX: 0000000000000000 RSI: 0000000000000018 RDI: 000000000000008e
RBP: ffffc90001026e78 R08: 0000000000000010 R09: 000000000000043b
R10: dffffc0000000000 R11: ffffed10235c802a R12: dffffc0000000000
R13: 000000000000008e R14: 0000000000000030 R15: 0000000000000010
FS:  00007f27f060f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7be1b68060 CR3: 000000012e1e1000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400