------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1080 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:1080, CPU#1: syz.4.141/6714
Modules linked in:
CPU: 1 UID: 0 PID: 6714 Comm: syz.4.141 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
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 69 02 df ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 34 5e fb ff e8 7f a4 75 ff eb 8c e8 78 a4 75 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 6a a4 75 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc90003c163e8 EFLAGS: 00010293
RAX: ffffffff824efa28 RBX: ffff88805fa04128 RCX: ffff8880310d5c40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888070998001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100bf40826 R12: ffff88804f526a00
R13: ffff888033817a68 R14: ffff88805fa04128 R15: 0000000000000012
FS:  00007f1fd88ed6c0(0000) GS:ffff8881261c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 00000000322de000 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+0x5e6/0xaf0 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+0x2af/0x8b0 mm/filemap.c:4324
 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4467
 __kernel_write_iter+0x427/0x890 fs/read_write.c:621
 __kernel_write+0x106/0x170 fs/read_write.c:641
 __dump_emit fs/coredump.c:1226 [inline]
 dump_emit+0x8ec/0xab0 fs/coredump.c:1264
 elf_core_dump+0x2e5d/0x3ad0 fs/binfmt_elf.c:2088
 coredump_write+0x1221/0x1920 fs/coredump.c:1053
 do_coredump fs/coredump.c:1132 [inline]
 vfs_coredump+0x380d/0x4540 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:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
 irqentry_exit+0x212/0x680 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f1fda6bc821
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:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f1fda936090 RCX: 00007f1fda6bc819
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f1fda752c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f1fda936128 R14: 00007f1fda936090 R15: 00007ffd454a11f8
 </TASK>