Oops: general protection fault, probably for non-canonical address 0xdffffc000000013c: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000009e0-0x00000000000009e7]
CPU: 0 UID: 0 PID: 13386 Comm: syz.1.1840 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:task_work_pending include/linux/task_work.h:26 [inline]
RIP: 0010:task_work_cancel_match+0x86/0x250 kernel/task_work.c:124
Code: 40 04 00 f3 f3 f3 65 48 8b 05 7e a9 3c 12 48 89 44 24 70 31 c0 e8 8a 60 37 00 4c 89 f8 48 c7 44 24 38 00 00 00 00 48 c1 e8 03 <42> 80 3c 30 00 0f 85 7e 01 00 00 4c 8b b3 e0 09 00 00 4d 85 f6 75
RSP: 0000:ffffc90030b5fba8 EFLAGS: 00010206
RAX: 000000000000013c RBX: 0000000000000000 RCX: ffffc9000d406000
RDX: 0000000000080000 RSI: ffffffff81d0b696 RDI: 0000000000000000
RBP: 1ffff9200616bf78 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff81d0b230
R13: ffff888026caa440 R14: dffffc0000000000 R15: 00000000000009e0
FS:  0000000000000000(0000) GS:ffff88809714a000(0063) knlGS:00000000f5455b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000301fcff8 CR3: 000000005a38f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 task_work_cancel+0x23/0x30 kernel/task_work.c:187
 cancel_tsync_works security/landlock/tsync.c:415 [inline]
 landlock_restrict_sibling_threads+0xafe/0x1280 security/landlock/tsync.c:533
 __do_sys_landlock_restrict_self+0x5c9/0x9e0 security/landlock/syscalls.c:574
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x141/0x6b0 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0023:0xf7fb2f6c
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8
RSP: 002b:00000000f545550c EFLAGS: 00000292 ORIG_RAX: 00000000000001be
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000008
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:task_work_pending include/linux/task_work.h:26 [inline]
RIP: 0010:task_work_cancel_match+0x86/0x250 kernel/task_work.c:124
Code: 40 04 00 f3 f3 f3 65 48 8b 05 7e a9 3c 12 48 89 44 24 70 31 c0 e8 8a 60 37 00 4c 89 f8 48 c7 44 24 38 00 00 00 00 48 c1 e8 03 <42> 80 3c 30 00 0f 85 7e 01 00 00 4c 8b b3 e0 09 00 00 4d 85 f6 75
RSP: 0000:ffffc90030b5fba8 EFLAGS: 00010206
RAX: 000000000000013c RBX: 0000000000000000 RCX: ffffc9000d406000
RDX: 0000000000080000 RSI: ffffffff81d0b696 RDI: 0000000000000000
RBP: 1ffff9200616bf78 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff81d0b230
R13: ffff888026caa440 R14: dffffc0000000000 R15: 00000000000009e0
FS:  0000000000000000(0000) GS:ffff88809724a000(0063) knlGS:00000000f5455b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f74032f0 CR3: 000000005a38f000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	40 04 00             	rex add $0x0,%al
   3:	f3 f3 f3 65 48 8b 05 	repz repz repz mov %gs:0x123ca97e(%rip),%rax        # 0x123ca98c
   a:	7e a9 3c 12
   e:	48 89 44 24 70       	mov    %rax,0x70(%rsp)
  13:	31 c0                	xor    %eax,%eax
  15:	e8 8a 60 37 00       	call   0x3760a4
  1a:	4c 89 f8             	mov    %r15,%rax
  1d:	48 c7 44 24 38 00 00 	movq   $0x0,0x38(%rsp)
  24:	00 00
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1) <-- trapping instruction
  2f:	0f 85 7e 01 00 00    	jne    0x1b3
  35:	4c 8b b3 e0 09 00 00 	mov    0x9e0(%rbx),%r14
  3c:	4d 85 f6             	test   %r14,%r14
  3f:	75                   	.byte 0x75