syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 0 UID: 0 PID: 12251 Comm: syz.1.1058 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:bfs_move_block fs/bfs/file.c:43 [inline]
RIP: 0010:bfs_move_blocks fs/bfs/file.c:57 [inline]
RIP: 0010:bfs_get_block+0x589/0xae0 fs/bfs/file.c:126
Code: f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 00 c2 86 ff 49 8b 5d 20 4d 8d 66 28 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 48 8b 6c 24 18 74 08 4c 89 e7 e8 d4 c1 86 ff 4c 89 ef
RSP: 0018:ffffc900057be358 EFLAGS: 00010216
RAX: 0000000000000005 RBX: 0000000000000200 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88807e1902d8
RBP: ffff888023094ea8 R08: ffffea00013f31f7 R09: 1ffffd400027e63e
R10: dffffc0000000000 R11: fffff9400027e63f R12: 0000000000000028
R13: ffff88807e1902b8 R14: 0000000000000000 R15: 0000000000000012
FS:  00007fc5aeb716c0(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003000 CR3: 000000009d070000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2042
 block_write_begin+0x8d/0x120 fs/buffer.c:2153
 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
 __kernel_write+0x106/0x170 fs/read_write.c:641
 __dump_emit fs/coredump.c:1226 [inline]
 dump_emit+0x8e9/0xab0 fs/coredump.c:1264
 writenote+0xfc/0x2f0 fs/binfmt_elf.c:1432
 write_note_info fs/binfmt_elf.c:1939 [inline]
 elf_core_dump+0x300c/0x3ad0 fs/binfmt_elf.c:2096
 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/0x840 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+0x289/0x760 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fc5add9cde1
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: 00007fc5ae016090 RCX: 00007fc5add9cdd9
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007fc5ade32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fc5ae016128 R14: 00007fc5ae016090 R15: 00007ffc0b95d6e8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bfs_move_block fs/bfs/file.c:43 [inline]
RIP: 0010:bfs_move_blocks fs/bfs/file.c:57 [inline]
RIP: 0010:bfs_get_block+0x589/0xae0 fs/bfs/file.c:126
Code: f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 00 c2 86 ff 49 8b 5d 20 4d 8d 66 28 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 48 8b 6c 24 18 74 08 4c 89 e7 e8 d4 c1 86 ff 4c 89 ef
RSP: 0018:ffffc900057be358 EFLAGS: 00010216
RAX: 0000000000000005 RBX: 0000000000000200 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88807e1902d8
RBP: ffff888023094ea8 R08: ffffea00013f31f7 R09: 1ffffd400027e63e
R10: dffffc0000000000 R11: fffff9400027e63f R12: 0000000000000028
R13: ffff88807e1902b8 R14: 0000000000000000 R15: 0000000000000012
FS:  00007fc5aeb716c0(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c345ab1 CR3: 000000009d070000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	f8                   	clc
   1:	48 c1 e8 03          	shr    $0x3,%rax
   5:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
   a:	74 05                	je     0x11
   c:	e8 00 c2 86 ff       	call   0xff86c211
  11:	49 8b 5d 20          	mov    0x20(%r13),%rbx
  15:	4d 8d 66 28          	lea    0x28(%r14),%r12
  19:	4c 89 e0             	mov    %r12,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	48 8b 6c 24 18       	mov    0x18(%rsp),%rbp
  33:	74 08                	je     0x3d
  35:	4c 89 e7             	mov    %r12,%rdi
  38:	e8 d4 c1 86 ff       	call   0xff86c211
  3d:	4c 89 ef             	mov    %r13,%rdi