Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 0 PID: 46 Comm: kworker/u4:3 Not tainted 6.14.0-rc3-syzkaller-g0ad2507d5d93 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: loop0 loop_rootcg_workfn
RIP: 0010:atime_needs_update+0x4b/0x6c0 fs/inode.c:2144
Code: df e8 49 ec 7e ff 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 a3 2c e6 ff 4c 8b 33 48 8d 5d 0c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 1b 05 00 00 8b 1b 89 de 83 e6 02 31 ff
RSP: 0018:ffffc90000617330 EFLAGS: 00010203
RAX: 0000000000000001 RBX: 000000000000000c RCX: ffff88801e610000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888044392780
RBP: 0000000000000000 R08: ffffffff8205f71d R09: 1ffffd400021c106
R10: dffffc0000000000 R11: fffff9400021c107 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88801c6f3020 R15: ffff88801c6f3020
FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f08517ff000 CR3: 000000004298c000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 touch_atime+0x84/0x690 fs/inode.c:2180
 file_accessed include/linux/fs.h:2601 [inline]
 shmem_file_read_iter+0x865/0x990 mm/shmem.c:3434
 do_iter_readv_writev+0x71a/0x9d0
 vfs_iter_read+0x154/0x460 fs/read_write.c:909
 lo_read_simple drivers/block/loop.c:285 [inline]
 do_req_filebacked drivers/block/loop.c:525 [inline]
 loop_handle_cmd drivers/block/loop.c:1929 [inline]
 loop_process_work+0xd72/0x21c0 drivers/block/loop.c:1964
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	df e8                	fucomip %st(0),%st
   2:	49 ec                	rex.WB in (%dx),%al
   4:	7e ff                	jle    0x5
   6:	48 89 d8             	mov    %rbx,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  12:	74 08                	je     0x1c
  14:	48 89 df             	mov    %rbx,%rdi
  17:	e8 a3 2c e6 ff       	call   0xffe62cbf
  1c:	4c 8b 33             	mov    (%rbx),%r14
  1f:	48 8d 5d 0c          	lea    0xc(%rbp),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 1b 05 00 00    	jne    0x552
  37:	8b 1b                	mov    (%rbx),%ebx
  39:	89 de                	mov    %ebx,%esi
  3b:	83 e6 02             	and    $0x2,%esi
  3e:	31 ff                	xor    %edi,%edi