From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f78.google.com (mail-ot1-f78.google.com [209.85.210.78]) (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 CCE723859C7 for ; Sat, 25 Apr 2026 09:32:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777109557; cv=none; b=p5paMA306G6NzxJeUuz7RzfKYVr7Y9E5FQCebWcpSul24sjqltvhK4l3iaB9Tu2vgogX1sfXbcuBUCrcVPbdhMP1ILhsmRU9U5/wiAapUREPQGhTfKsBXrozi4+0dKW7Kc2gM8uMTTz7lN/IcRDxxo8b28DQXTxNUoWDiAQ4hvE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777109557; c=relaxed/simple; bh=q4zCQhWs4Kl1t05h3f3dc7zzs9opBi9pGpgRx2Rd9os=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=nMgn645lUbTTPPN7C+U32ygbj8/A0PtuQW+rHnmVDApSKgo3OBv3Q4mZgZdmQ1MW8TyRp3EqIbUhjI7gEUaprMhVH0e9CGgTwSjkSx3vutOaKWF8KBKFrz/QiZ2ux8aFeVMKjpv+fD52UdBvkeuCzqpE1AlwyGTjt3igSH3jlhU= 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=209.85.210.78 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-ot1-f78.google.com with SMTP id 46e09a7af769-7dcdcacd141so6742554a34.2 for ; Sat, 25 Apr 2026 02:32:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777109555; x=1777714355; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=bA/GX3iTFBK/+UL89+u/hJNZRb5v6ZqgBIyssV+uBSc=; b=Ckad/LqHCjdaNuibuWFNaAM27/RKHvQTXL2+xzzQImDmT0bEWDd9HrjT8IuzC76dxc 6RHwmuPHPV1VpZ2lmue1c64wCBmfhwiFgJhpNCPsji4MsNBXxjSvwbYHkIoXGEiUiTX7 vo7hHwPkQ5wtMrkPvWI0ID4rrGMU4QZVaqwemqK9U/qTTOyaNLh+9Kvcb9Q5p0LTjwDi rYow9ENgAQJc6BgsS1rQfBaJp/TVs/yXOU3DNVEnYK5inOyzBTSiDNhiNxAIN8GT09IG GoB3Wh7pHq38Xd+TbUHNA5yCG+7iCJ4t3W1hbZLxBm2EqtHtFDY5xbFr4NPN7Kjo81y5 Y8ow== X-Forwarded-Encrypted: i=1; AFNElJ/jMUvfKushoe6SNLwdyNPbsTrME+FtBckZwAc7u4cheD2yYwwFZJz4t69S0R6YcaGm2Wp5tK9/y81RONQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxcTM5bMJPSX6Jw3+yXhUlOSHFMp8fV268Q4X+W5AvFIwh9eaUs wHLC2kvqhN1H7lLXOZElxLGTMLE0yKZUFK3ZS3AofYA2I1c2KIZD/AgV+cBW+55nyl84/NlZ6zA viVDFiKqXZSjOm5zdap3hMuYmqQgwsbjH4VqWdzN4bBrk0mTGhQRuuKRlTbY= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a4a:e905:0:b0:694:8ba4:e3bd with SMTP id 006d021491bc7-6948ba4ed63mr13751317eaf.36.1777109554897; Sat, 25 Apr 2026 02:32:34 -0700 (PDT) Date: Sat, 25 Apr 2026 02:32:34 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69ec8a32.a00a0220.1901e8.000b.GAE@google.com> Subject: [syzbot] [mm?] WARNING: lock held when returning to user space in __pte_offset_map From: syzbot To: Liam.Howlett@oracle.com, akpm@linux-foundation.org, david@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, mhocko@suse.com, rppt@kernel.org, surenb@google.com, syzkaller-bugs@googlegroups.com, vbabka@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: dd6c438c3e64 Merge tag 'vfs-7.1-rc1.fixes' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=145bec36580000 kernel config: https://syzkaller.appspot.com/x/.config?x=ed9f32dc64d6a2f2 dashboard link: https://syzkaller.appspot.com/bug?extid=2e8b7c8cf82134e81378 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/926b34cf03cd/disk-dd6c438c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/020eae7c763c/vmlinux-dd6c438c.xz kernel image: https://storage.googleapis.com/syzbot-assets/8f652b84678d/bzImage-dd6c438c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2e8b7c8cf82134e81378@syzkaller.appspotmail.com ================================================ WARNING: lock held when returning to user space! syzkaller #0 Not tainted ------------------------------------------------ udevd/5800 is leaving the kernel with locks still held! 1 lock held by udevd/5800: #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 ------------[ cut here ]------------ Voluntary context switch within RCU read-side critical section! WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0xcac/0xf40 kernel/rcu/tree_plugin.h:332, CPU#0: udevd/5800 Modules linked in: CPU: 0 UID: 0 PID: 5800 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:rcu_note_context_switch+0xcac/0xf40 kernel/rcu/tree_plugin.h:332 Code: 00 41 c6 45 00 00 48 8b 3d 21 24 e1 0d 48 81 c4 b8 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 bb 5f ff ff 48 8d 3d 24 e7 e4 0d <67> 48 0f b9 3a e9 1b f4 ff ff 90 0f 0b 90 45 84 e4 0f 84 ea f3 ff RSP: 0000:ffffc90004477b90 EFLAGS: 00010002 RAX: 0000000000000000 RBX: ffff888039ac9ec0 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff8ba73c40 RDI: ffffffff8f8f4250 RBP: dffffc0000000000 R08: ffffffff8f8bd1f7 R09: 1ffffffff1f17a3e R10: dffffc0000000000 R11: fffffbfff1f17a3f R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8880b883c800 R15: ffff888039aca384 FS: 00007f74fc12d880(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055de63bc0d08 CR3: 0000000031232000 CR4: 00000000003526f0 Call Trace: __schedule+0x291/0x54c0 kernel/sched/core.c:7043 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 __exit_to_user_mode_loop kernel/entry/common.c:54 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline] irqentry_exit+0x263/0x730 kernel/entry/common.c:162 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0033:0x7f74fc8d1a9a Code: 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 53 48 85 ff 74 2f 48 8b 47 08 48 39 c7 74 21 48 8b 1f 48 39 df 74 19 48 89 18 <48> 89 43 08 e8 8d d9 ff ff 48 89 d8 5b c3 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffceb76a200 EFLAGS: 00010283 RAX: 000055de63bbd0b0 RBX: 000055de63bc0d00 RCX: 0000000000000000 RDX: 000055de63bbf070 RSI: 000055de63bc5ae0 RDI: 000055de63bbcf10 RBP: 000055de63bbcf10 R08: 000055de63bc5af0 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000297 R12: 000055de3e623588 R13: 00007ffceb76a2b0 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 00 41 c6 add %al,-0x3a(%rcx) 3: 45 00 00 add %r8b,(%r8) 6: 48 8b 3d 21 24 e1 0d mov 0xde12421(%rip),%rdi # 0xde1242e d: 48 81 c4 b8 00 00 00 add $0xb8,%rsp 14: 5b pop %rbx 15: 41 5c pop %r12 17: 41 5d pop %r13 19: 41 5e pop %r14 1b: 41 5f pop %r15 1d: 5d pop %rbp 1e: e9 bb 5f ff ff jmp 0xffff5fde 23: 48 8d 3d 24 e7 e4 0d lea 0xde4e724(%rip),%rdi # 0xde4e74e * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: e9 1b f4 ff ff jmp 0xfffff44f 34: 90 nop 35: 0f 0b ud2 37: 90 nop 38: 45 84 e4 test %r12b,%r12b 3b: 0f .byte 0xf 3c: 84 ea test %ch,%dl 3e: f3 repz 3f: ff .byte 0xff --- 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