RBP: 0000000000000014 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000015: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
CPU: 3 UID: 0 PID: 11789 Comm: syz.3.1657 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:netfs_prepare_write+0xbc/0x7b0 fs/netfs/write_issue.c:173
Code: e1 07 38 ca 7f 08 84 d2 0f 85 04 06 00 00 48 8d bb ad 00 00 00 0f b6 45 52 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 <0f> b6 14 11 48 89 f9 83 e1 07 38 ca 7f 08 84 d2 0f 85 c1 05 00 00
RSP: 0000:ffffc90005d57590 EFLAGS: 00010203
RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000015
RDX: dffffc0000000000 RSI: ffffffff82cdb989 RDI: 00000000000000ad
RBP: ffff888013f12660 R08: 00000000ffffffff R09: fffffbfff1dff4ee
R10: ffffffff8effa773 R11: 0000000000000001 R12: ffff888013f12580
R13: ffff888013f12738 R14: 0000000000000000 R15: ffff888013f126b2
FS:  0000000000000000(0000) GS:ffff888096c82000(0063) knlGS:00000000f53e5b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7f47000 CR3: 0000000026445000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 netfs_advance_write fs/netfs/write_issue.c:298 [inline]
 netfs_advance_write+0x3af/0x4c0 fs/netfs/write_issue.c:278
 netfs_write_folio+0xc7b/0x1890 fs/netfs/write_issue.c:493
 netfs_advance_writethrough+0x262/0x4d0 fs/netfs/write_issue.c:677
 netfs_perform_write+0x1604/0x25a0 fs/netfs/buffered_write.c:397
 netfs_buffered_write_iter_locked+0x224/0x2c0 fs/netfs/buffered_write.c:484
 netfs_file_write_iter+0x1da/0x4a0 fs/netfs/buffered_write.c:523
 v9fs_file_write_iter+0x9b/0x100 fs/9p/vfs_file.c:412
 do_iter_readv_writev+0x6f7/0x930 fs/read_write.c:828
 vfs_writev+0x360/0xdd0 fs/read_write.c:1058
 do_pwritev+0x1ac/0x270 fs/read_write.c:1154
 __do_compat_sys_pwritev2 fs/read_write.c:1299 [inline]
 __se_compat_sys_pwritev2 fs/read_write.c:1291 [inline]
 __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1291
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f46fec
Code: Unable to access opcode bytes at 0xf7f46fc2.
RSP: 002b:00000000f53e550c EFLAGS: 00000292 ORIG_RAX: 000000000000017b
RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 0000000080000980
RDX: 0000000000000001 RSI: 0000000000000005 RDI: 000000000000000a
RBP: 0000000000000014 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:netfs_prepare_write+0xbc/0x7b0 fs/netfs/write_issue.c:173
Code: e1 07 38 ca 7f 08 84 d2 0f 85 04 06 00 00 48 8d bb ad 00 00 00 0f b6 45 52 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 <0f> b6 14 11 48 89 f9 83 e1 07 38 ca 7f 08 84 d2 0f 85 c1 05 00 00
RSP: 0000:ffffc90005d57590 EFLAGS: 00010203
RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000015
RDX: dffffc0000000000 RSI: ffffffff82cdb989 RDI: 00000000000000ad
RBP: ffff888013f12660 R08: 00000000ffffffff R09: fffffbfff1dff4ee
R10: ffffffff8effa773 R11: 0000000000000001 R12: ffff888013f12580
R13: ffff888013f12738 R14: 0000000000000000 R15: ffff888013f126b2
FS:  0000000000000000(0000) GS:ffff888096c82000(0063) knlGS:00000000f53e5b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f71c8b50 CR3: 0000000026445000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e1 07                	loope  0x9
   2:	38 ca                	cmp    %cl,%dl
   4:	7f 08                	jg     0xe
   6:	84 d2                	test   %dl,%dl
   8:	0f 85 04 06 00 00    	jne    0x612
   e:	48 8d bb ad 00 00 00 	lea    0xad(%rbx),%rdi
  15:	0f b6 45 52          	movzbl 0x52(%rbp),%eax
  19:	48 ba 00 00 00 00 00 	movabs $0xdffffc0000000000,%rdx
  20:	fc ff df
  23:	48 89 f9             	mov    %rdi,%rcx
  26:	48 c1 e9 03          	shr    $0x3,%rcx
* 2a:	0f b6 14 11          	movzbl (%rcx,%rdx,1),%edx <-- trapping instruction
  2e:	48 89 f9             	mov    %rdi,%rcx
  31:	83 e1 07             	and    $0x7,%ecx
  34:	38 ca                	cmp    %cl,%dl
  36:	7f 08                	jg     0x40
  38:	84 d2                	test   %dl,%dl
  3a:	0f 85 c1 05 00 00    	jne    0x601