From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f72.google.com (mail-oo1-f72.google.com [209.85.161.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 823C2368979 for ; Sat, 7 Mar 2026 05:17:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772860647; cv=none; b=S5wmeuDe6Jy07LCxfgjcdGrHNSb07nYUjep4203TfG2XEaGBKo9il3JjZ3QQDChEuiZ8Ef3TQcdeC7VQDrSbZX/dUmE0277MhY+pNpArmb6p28+0GOsfn7TUneLletP7DxkkTyGyjzL0t9OauMsO21l660Dsf6KTbvfo+eZyzIQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772860647; c=relaxed/simple; bh=sidpDry/1YSxD7VS0wn8oHnhVtzSpXG4bKXYCrFXn+A=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=RkRNWABvLwcitGRVRJT9PF3q28CyOQpYqUILB2bkHCkJQujWxhiU8siW+hrX7ureZcIQ+mwaVSIVb5l5u7cQdOC4Zmgo0T01sBXaTD+cn0NFYLD3CdDHXOvW4kdvYiiYG8bnWmCMdCWtk8aAtO2oTeuC4ew9f7czFXXocqhcDR8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f72.google.com with SMTP id 006d021491bc7-679862e4413so146760451eaf.0 for ; Fri, 06 Mar 2026 21:17:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772860643; x=1773465443; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=rtNDNy3omDCkiXXXfRkTX0dfXeoEf5yYzncrsz3Me/I=; b=fsVf7DCXqAgdhwBKXRhBoJkoHcLGbzX6qaRWGYzFf/dSyxAgp4MMrhKjcfTNwl0D+T 6ofR7vj+XlXqE3d1OCv1hEsEZgda4tcO6Om49UDbyC9MjckhjW3M9abVjm32WkgcfG40 4xinUWx9IgJaUOJqeoLhdEqYvi5Cq47A43lhH+OvlF6Hut/+tRLZXg/coC706W1ZXKRl gASlOoBkjXi49TidlOlFLFZmbv4HirXgadu5w/ua9Qz6gkpGpOsczDCVDEesBiIiDiSL 1TCxCtnZYb4NQljCWfEhiRJRn2OhE9frxjtN0EVEq4UUD9ZUIwgVWpWHeuMkWqYMwdH8 dlnQ== X-Gm-Message-State: AOJu0YxK8SQNQIL2eVTjD1aaH0c56Dnr6zexsCVsbMu6p6POLrth4EKw XpZpscF19nW6+g8nWXSaZ8GDvf8kuL4DZeT4rZNlLACpm8z2C+gX9xRZW58ZSKJ7z0lhf7zTLKb DXNDuxfNog4kLo8KI+HdCiVdzVLqsV1ZYwzB9bb8yvP46VwZW3COEgOzcMQw= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:203:b0:672:a49f:128e with SMTP id 006d021491bc7-67b9bc65c05mr3540144eaf.8.1772860643341; Fri, 06 Mar 2026 21:17:23 -0800 (PST) Date: Fri, 06 Mar 2026 21:17:23 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69abb4e3.050a0220.13f275.003d.GAE@google.com> Subject: [syzbot] [kernel?] general protection fault in task_work_cancel From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: af4e9ef3d784 uaccess: Fix scoped_user_read_access() for 'p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13774952580000 kernel config: https://syzkaller.appspot.com/x/.config?x=779072223d02a312 dashboard link: https://syzkaller.appspot.com/bug?extid=741e2278ef71fef03a10 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/f6b75c8f432f/disk-af4e9ef3.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4513ad566789/vmlinux-af4e9ef3.xz kernel image: https://storage.googleapis.com/syzbot-assets/f7eea878db42/bzImage-af4e9ef3.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+741e2278ef71fef03a10@syzkaller.appspotmail.com Oops: general protection fault, probably for non-canonical address 0xdffffc000000013c: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000009e0-0x00000000000009e7] CPU: 1 UID: 0 PID: 8400 Comm: syz.0.629 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:task_work_pending include/linux/task_work.h:26 [inline] RIP: 0010:task_work_cancel_match kernel/task_work.c:124 [inline] RIP: 0010:task_work_cancel+0x8a/0x220 kernel/task_work.c:187 Code: b8 f1 f1 f1 f1 f8 f3 f3 f3 4b 89 44 25 00 e8 bd b6 35 00 43 c6 44 25 04 00 49 89 de 48 81 c3 e0 09 00 00 49 89 df 49 c1 ef 03 <43> 80 3c 27 00 74 08 48 89 df e8 17 f5 9f 00 48 83 3b 00 75 51 e8 RSP: 0018:ffffc9001eadfb20 EFLAGS: 00010216 RAX: ffffffff818fdf23 RBX: 00000000000009e0 RCX: 0000000000080000 RDX: ffffc9000e905000 RSI: 00000000000099dd RDI: 00000000000099de RBP: ffffc9001eadfbd0 R08: ffffc9001eadfc97 R09: 1ffff92003d5bf92 R10: dffffc0000000000 R11: fffff52003d5bf93 R12: dffffc0000000000 R13: 1ffff92003d5bf68 R14: 0000000000000000 R15: 000000000000013c FS: 00007f83f86a96c0(0000) GS:ffff888125564000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff8027ea4b8 CR3: 0000000021f07000 CR4: 0000000000350ef0 Call Trace: cancel_tsync_works security/landlock/tsync.c:415 [inline] landlock_restrict_sibling_threads+0xdc4/0x11f0 security/landlock/tsync.c:533 __do_sys_landlock_restrict_self security/landlock/syscalls.c:574 [inline] __se_sys_landlock_restrict_self+0x540/0x810 security/landlock/syscalls.c:482 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f83f779c799 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:00007f83f86a9028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f83f7a16090 RCX: 00007f83f779c799 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000004 RBP: 00007f83f7832bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f83f7a16128 R14: 00007f83f7a16090 R15: 00007fff928f0338 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:task_work_pending include/linux/task_work.h:26 [inline] RIP: 0010:task_work_cancel_match kernel/task_work.c:124 [inline] RIP: 0010:task_work_cancel+0x8a/0x220 kernel/task_work.c:187 Code: b8 f1 f1 f1 f1 f8 f3 f3 f3 4b 89 44 25 00 e8 bd b6 35 00 43 c6 44 25 04 00 49 89 de 48 81 c3 e0 09 00 00 49 89 df 49 c1 ef 03 <43> 80 3c 27 00 74 08 48 89 df e8 17 f5 9f 00 48 83 3b 00 75 51 e8 RSP: 0018:ffffc9001eadfb20 EFLAGS: 00010216 RAX: ffffffff818fdf23 RBX: 00000000000009e0 RCX: 0000000000080000 RDX: ffffc9000e905000 RSI: 00000000000099dd RDI: 00000000000099de RBP: ffffc9001eadfbd0 R08: ffffc9001eadfc97 R09: 1ffff92003d5bf92 R10: dffffc0000000000 R11: fffff52003d5bf93 R12: dffffc0000000000 R13: 1ffff92003d5bf68 R14: 0000000000000000 R15: 000000000000013c FS: 00007f83f86a96c0(0000) GS:ffff888125564000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faa33e5c000 CR3: 0000000021f07000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: b8 f1 f1 f1 f1 mov $0xf1f1f1f1,%eax 5: f8 clc 6: f3 f3 f3 4b 89 44 25 repz repz xrelease mov %rax,0x0(%r13,%r12,1) d: 00 e: e8 bd b6 35 00 call 0x35b6d0 13: 43 c6 44 25 04 00 movb $0x0,0x4(%r13,%r12,1) 19: 49 89 de mov %rbx,%r14 1c: 48 81 c3 e0 09 00 00 add $0x9e0,%rbx 23: 49 89 df mov %rbx,%r15 26: 49 c1 ef 03 shr $0x3,%r15 * 2a: 43 80 3c 27 00 cmpb $0x0,(%r15,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 17 f5 9f 00 call 0x9ff550 39: 48 83 3b 00 cmpq $0x0,(%rbx) 3d: 75 51 jne 0x90 3f: e8 .byte 0xe8 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup