Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted 6.12.0-rc7-syzkaller-00042-gf1b785f4c787 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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+0xa75/0xb70 fs/bfs/file.c:126
Code: 00 41 8b 0f b8 77 7f ff ff 21 c1 81 c9 08 80 00 00 4c 89 ef 4c 89 f6 e8 d9 12 a0 ff 49 89 c5 48 8d 68 28 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 dc 6e 7b ff 4c 8b 75 00 48 8d 7b
RSP: 0018:ffffc9000d036bd0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff888043df5e80 RCX: ffff888000b04880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000028 R08: ffffffff82235c47 R09: 1ffffd40002886be
R10: dffffc0000000000 R11: fffff940002886bf R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000045 R15: ffff888031ce4e68
FS:  00007f8de0d016c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff11d27f04 CR3: 000000005183a000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2121
 block_write_begin+0x8f/0x120 fs/buffer.c:2231
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:179
 generic_perform_write+0x344/0x6d0 mm/filemap.c:4054
 generic_file_write_iter+0xae/0x310 mm/filemap.c:4181
 __kernel_write_iter+0x42a/0x940 fs/read_write.c:616
 __kernel_write+0x120/0x180 fs/read_write.c:636
 __dump_emit+0x237/0x360 fs/coredump.c:807
 writenote+0x221/0x3b0 fs/binfmt_elf.c:1463
 write_note_info fs/binfmt_elf.c:1941 [inline]
 elf_core_dump+0x37ba/0x4770 fs/binfmt_elf.c:2108
 do_coredump+0x2162/0x2ec0 fs/coredump.c:758
 get_signal+0x13fc/0x1740 kernel/signal.c:2903
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </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+0xa75/0xb70 fs/bfs/file.c:126
Code: 00 41 8b 0f b8 77 7f ff ff 21 c1 81 c9 08 80 00 00 4c 89 ef 4c 89 f6 e8 d9 12 a0 ff 49 89 c5 48 8d 68 28 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 dc 6e 7b ff 4c 8b 75 00 48 8d 7b
RSP: 0018:ffffc9000d036bd0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff888043df5e80 RCX: ffff888000b04880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000028 R08: ffffffff82235c47 R09: 1ffffd40002886be
R10: dffffc0000000000 R11: fffff940002886bf R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000045 R15: ffff888031ce4e68
FS:  00007f8de0d016c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000005183a000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	41 8b 0f             	mov    (%r15),%ecx
   3:	b8 77 7f ff ff       	mov    $0xffff7f77,%eax
   8:	21 c1                	and    %eax,%ecx
   a:	81 c9 08 80 00 00    	or     $0x8008,%ecx
  10:	4c 89 ef             	mov    %r13,%rdi
  13:	4c 89 f6             	mov    %r14,%rsi
  16:	e8 d9 12 a0 ff       	call   0xffa012f4
  1b:	49 89 c5             	mov    %rax,%r13
  1e:	48 8d 68 28          	lea    0x28(%rax),%rbp
  22:	48 89 e8             	mov    %rbp,%rax
  25:	48 c1 e8 03          	shr    $0x3,%rax
* 29:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	48 89 ef             	mov    %rbp,%rdi
  33:	e8 dc 6e 7b ff       	call   0xff7b6f14
  38:	4c 8b 75 00          	mov    0x0(%rbp),%r14
  3c:	48                   	rex.W
  3d:	8d                   	.byte 0x8d
  3e:	7b                   	.byte 0x7b