------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:3186!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 939 Comm: syz.5.196 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:ffffc900031962a0 EFLAGS: 00010293
RAX: ffffffff81d61682 RBX: 0000000000000004 RCX: ffff8881183aa780
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000040
RBP: ffffc90003196418 R08: 0000000000000017 R09: 000000000000043b
R10: dffffc0000000000 R11: ffffed10234ffcaa R12: dffffc0000000000
R13: 0000000000000040 R14: 0000000000000030 R15: 0000000000000017
FS:  00007fd4858eb6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 0000000128eed000 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
 __kernel_write+0x510/0x950 fs/read_write.c:539
 __dump_emit+0x246/0x370 fs/coredump.c:880
 dump_emit+0x383/0x3f0 fs/coredump.c:917
 dump_user_range+0x86/0x1c0 fs/coredump.c:954
 elf_core_dump+0x2a8f/0x2fd0 fs/binfmt_elf.c:2285
 do_coredump+0x1452/0x2950 fs/coredump.c:831
 get_signal+0x38d/0x1480 kernel/signal.c:2893
 arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:320
 irqentry_exit+0x12/0x40 kernel/entry/common.c:411
 exc_page_fault+0x5e/0xb0 arch/x86/mm/fault.c:1563
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fd486e907a1
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fd487109fa0 RCX: 00007fd486e90799
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fd486f26bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd48710a038 R14: 00007fd487109fa0 R15: 00007ffe786815b8
 </TASK>
Modules linked in:
---[ end trace ead93c48dc54fdef ]---
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:ffffc900031962a0 EFLAGS: 00010293
RAX: ffffffff81d61682 RBX: 0000000000000004 RCX: ffff8881183aa780
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000040
RBP: ffffc90003196418 R08: 0000000000000017 R09: 000000000000043b
R10: dffffc0000000000 R11: ffffed10234ffcaa R12: dffffc0000000000
R13: 0000000000000040 R14: 0000000000000030 R15: 0000000000000017
FS:  00007fd4858eb6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7867dff0 CR3: 0000000128eed000 CR4: 00000000003506a0