[moderation] [kernel?] general protection fault in task_work_cancel_match

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 26a4cfaff82a Merge tag 'docs-7.0-2' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=117e4652580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ae64e1f7eb66f647
dashboard link: https://syzkaller.appspot.com/bug?extid=911d99dc200feac03ea6
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
CC: [linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-26a4cfaf.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5af5f96a3ff9/vmlinux-26a4cfaf.xz
kernel image: https://storage.googleapis.com/syzbot-assets/521c524210ea/bzImage-26a4cfaf.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+911d99...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000134: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000009a0-0x00000000000009a7]
CPU: 1 UID: 0 PID: 13609 Comm: syz.9.2062 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
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 ee b8 3b 12 48 89 44 24 70 31 c0 e8 9a 71 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 a0 09 00 00 4d 85 f6 75
RSP: 0018:ffffc900037cfba0 EFLAGS: 00010202
RAX: 0000000000000134 RBX: 0000000000000000 RCX: ffffffff84b69dbb
RDX: ffff88802ed7a480 RSI: ffffffff81d12726 RDI: 0000000000000000
RBP: 1ffff920006f9f77 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000001 R12: ffffffff81d122c0
R13: ffff888022668480 R14: dffffc0000000000 R15: 00000000000009a0
FS: 00007f1075ca86c0(0000) GS:ffff8880d6452000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000491e2000 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_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1074d9bf79
Code: ff c3 66 2e 0f 1f 84 00 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
RSP: 002b:00007f1075ca8028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be
RAX: ffffffffffffffda RBX: 00007f1075016180 RCX: 00007f1074d9bf79
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000044
RBP: 00007f1074e327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1075016218 R14: 00007f1075016180 R15: 00007ffeb2b681a8
</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 ee b8 3b 12 48 89 44 24 70 31 c0 e8 9a 71 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 a0 09 00 00 4d 85 f6 75
RSP: 0018:ffffc900037cfba0 EFLAGS: 00010202
RAX: 0000000000000134 RBX: 0000000000000000 RCX: ffffffff84b69dbb
RDX: ffff88802ed7a480 RSI: ffffffff81d12726 RDI: 0000000000000000
RBP: 1ffff920006f9f77 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000001 R12: ffffffff81d122c0
R13: ffff888022668480 R14: dffffc0000000000 R15: 00000000000009a0
FS: 00007f1075ca86c0(0000) GS:ffff8880d6352000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fed16217dac CR3: 00000000491e2000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000080083
DR3: ffffffffefffff16 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
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:0x123bb8ee(%rip),%rax # 0x123bb8fc
a: ee b8 3b 12
e: 48 89 44 24 70 mov %rax,0x70(%rsp)
13: 31 c0 xor %eax,%eax
15: e8 9a 71 37 00 call 0x3771b4
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 a0 09 00 00 mov 0x9a0(%rbx),%r14
3c: 4d 85 f6 test %r14,%r14
3f: 75 .byte 0x75


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