------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:3187!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1445 Comm: syz.6.291 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_split_extent_at+0xf50/0xf70 fs/ext4/extents.c:3187
Code: ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 45 fb ff ff 4c 89 f7 49 89 f7 e8 3d bc cf ff 4c 89 fe e9 32 fb ff ff e8 10 8a 8a ff <0f> 0b e8 09 8a 8a ff 0f 0b e8 02 8a 8a ff 0f 0b e8 fb 89 8a ff 0f
RSP: 0018:ffffc90000dee360 EFLAGS: 00010293
RAX: ffffffff81e6e2f0 RBX: 0000000000000008 RCX: ffff888121866540
RDX: 0000000000000000 RSI: 0000000000000019 RDI: 00000000000000b0
RBP: ffffc90000dee4d8 R08: 0000000000000010 R09: 000000000000043b
R10: dffffc0000000000 R11: ffffed102945fe4a R12: dffffc0000000000
R13: 0000000000000011 R14: 0000000000000010 R15: ffff88814a2ff200
FS:  00007eff0c4836c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 000000012a683000 CR4: 00000000003526b0
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+0x10e5/0x61d0 fs/ext4/extents.c:4231
 ext4_map_blocks+0x9d8/0x1b70 fs/ext4/inode.c:679
 mpage_map_one_extent fs/ext4/inode.c:2435 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2488 [inline]
 ext4_writepages+0x1409/0x30e0 fs/ext4/inode.c:2856
 do_writepages+0x3a4/0x5f0 mm/page-writeback.c:2494
 filemap_fdatawrite_wbc+0x128/0x190 mm/filemap.c:408
 __filemap_fdatawrite_range mm/filemap.c:441 [inline]
 file_write_and_wait_range+0x159/0x230 mm/filemap.c:794
 ext4_sync_file+0x1a9/0xa10 fs/ext4/fsync.c:151
 vfs_fsync_range+0x1a1/0x1b0 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2980 [inline]
 ext4_buffered_write_iter+0x573/0x630 fs/ext4/file.c:292
 ext4_file_write_iter+0x191/0x1500 fs/ext4/file.c:-1
 __kernel_write_iter+0x296/0x660 fs/read_write.c:517
 dump_emit_page fs/coredump.c:886 [inline]
 dump_user_range+0x40b/0x660 fs/coredump.c:913
 elf_core_dump+0x2b52/0x3060 fs/binfmt_elf.c:2354
 do_coredump+0x15d3/0x2240 fs/coredump.c:760
 get_signal+0x11db/0x1520 kernel/signal.c:2877
 arch_do_signal_or_restart+0xd1/0x1140 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:316
 irqentry_exit+0x12/0x40 kernel/entry/common.c:419
 exc_page_fault+0x5e/0xb0 arch/x86/mm/fault.c:1520
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7eff0b59c7a1
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: 00007eff0b815fa0 RCX: 00007eff0b59c799
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007eff0b632bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007eff0b816038 R14: 00007eff0b815fa0 R15: 00007ffc1627ab18
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_split_extent_at+0xf50/0xf70 fs/ext4/extents.c:3187
Code: ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 45 fb ff ff 4c 89 f7 49 89 f7 e8 3d bc cf ff 4c 89 fe e9 32 fb ff ff e8 10 8a 8a ff <0f> 0b e8 09 8a 8a ff 0f 0b e8 02 8a 8a ff 0f 0b e8 fb 89 8a ff 0f
RSP: 0018:ffffc90000dee360 EFLAGS: 00010293
RAX: ffffffff81e6e2f0 RBX: 0000000000000008 RCX: ffff888121866540
RDX: 0000000000000000 RSI: 0000000000000019 RDI: 00000000000000b0
RBP: ffffc90000dee4d8 R08: 0000000000000010 R09: 000000000000043b
R10: dffffc0000000000 R11: ffffed102945fe4a R12: dffffc0000000000
R13: 0000000000000011 R14: 0000000000000010 R15: ffff88814a2ff200
FS:  00007eff0c4836c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff9c997ea4 CR3: 000000012a683000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400