------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1080 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:1080, CPU#1: syz.1.230/6962
Modules linked in:
CPU: 1 UID: 0 PID: 6962 Comm: syz.1.230 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:mark_buffer_dirty+0x299/0x410 fs/buffer.c:1080
Code: 4c 89 f7 e8 39 60 da ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 94 5e fb ff e8 4f f7 70 ff eb 8c e8 48 f7 70 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 3a f7 70 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0000:ffffc90006fc6468 EFLAGS: 00010293
RAX: ffffffff82552a48 RBX: ffff888076f47e80 RCX: ffff88802f201e80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff888035ae4001 R08: ffff888076f47e87 R09: 1ffff1100ede8fd0
R10: dffffc0000000000 R11: ffffed100ede8fd1 R12: ffff88804c279000
R13: ffff88806b1fe570 R14: ffff888076f47e80 R15: 000000000000000c
FS:  00007fe099bb06c0(0000) GS:ffff88812535c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcdc1b04000 CR3: 0000000022b24000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 bfs_move_block fs/bfs/file.c:44 [inline]
 bfs_move_blocks fs/bfs/file.c:57 [inline]
 bfs_get_block+0x5da/0xae0 fs/bfs/file.c:126
 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2035
 block_write_begin+0x8d/0x120 fs/buffer.c:2146
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180
 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4325
 generic_file_write_iter+0x14a/0x680 mm/filemap.c:4468
 __kernel_write_iter+0x41e/0x880 fs/read_write.c:621
 dump_emit_page fs/coredump.c:1304 [inline]
 dump_user_range+0xc19/0x12c0 fs/coredump.c:1378
 elf_core_dump+0x34c2/0x3ad0 fs/binfmt_elf.c:2109
 coredump_write+0x1216/0x1910 fs/coredump.c:1053
 do_coredump fs/coredump.c:1132 [inline]
 vfs_coredump+0x3807/0x4530 fs/coredump.c:1206
 get_signal+0x1107/0x1330 kernel/signal.c:3022
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:283 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:352 [inline]
 irqentry_exit+0x188/0x700 kernel/entry/common.c:219
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7502d2
Code: Unable to access opcode bytes at 0x7502a8.
RSP: 002b:00002000000000a8 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fe099016180 RCX: 00007fe098d9c819
RDX: 0000200000000140 RSI: 00002000000000a0 RDI: 0000000000200000
RBP: 00007fe098e32c91 R08: 00002000000001c0 R09: 00002000000001c0
R10: 0000200000000180 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fe099016218 R14: 00007fe099016180 R15: 00007ffe769c2bf8
 </TASK>