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 B20F8260580 for ; Wed, 29 Apr 2026 22:30:25 +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=1777501827; cv=none; b=JZQc12Cpk5FDT7xIJLdCZ+/PDelCiM8sue/Hnp09idc1RtABHh2QXv5s7BYzfBB3P261w70qEg+N2rUwpr8wA+sfiWickuuLF+OOEZdnYEtp9Kfbom3h1YRj6kCWOFZ6ZgxkkfTY8Hh4Gl3CqyY8WBya4UtuDQSp3Anje1sXj6Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777501827; c=relaxed/simple; bh=Ts4GU+a/vD4lw/fOfiL7N88Td58H/8nNsFCqYY4Btvs=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=G/4boZo/0HYHOKgWOOUFMNzto40TZkTEtnGFbiOHKCGyTaMVn1zNOfwZgWKT5rp/5jb1t4KQ1QQIei/TBcG0k1YTKjRP/xsL2Fk4JAGO/u7/5BZ9DEVPRVGnYRAAKLk83+vO1T0m+aEh9AHdvIQSKn8MhXgg33C8ZJJTUznhnkk= 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 46e09a7af769-7dcc79309d0so2380822a34.1 for ; Wed, 29 Apr 2026 15:30:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777501824; x=1778106624; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=3HbGDe+FYuDBiqHxgjl3AMAvxH4rr+6wviRQfjDUxY8=; b=ikecDD3F9ftx/jnJ6xFJH1LBw62uigy2nW4FXWeC2jVw4WOrQgBkkYFX+DpPL4iFns j+ChLSKLonmmFFO4g3jBO55001W6JnJERC2TFJcnLzPSHygLCpw+HCnO4ia++qAo1OVU 4emS6Ha8tK5MqGDkUOeLvR/bfjChhTsouoEmPCQlKYzmX1trse/ERluoMq2LY/FLwcFi cnPEis3bV0CyabWBBbfhrVtxaU30U3crIHpF7iG0wRXBwDTtTfoFrjxeRkIZW9TCiv62 fpnbIKRjgTz1CpP3I4xtRqDfN0Gb5QUsC3+5Db03D0kNb1bQSsFUyn8BnY40e6Z3rUnA wH1A== X-Forwarded-Encrypted: i=1; AFNElJ8JDR1TuSjpbYaHMcrXdOtUOMzzCDXsiTqeP+phneDswNhm6/8G8C+3oY0VgJC480oAOqqCi3SwF0iwlns=@vger.kernel.org X-Gm-Message-State: AOJu0YyTbXfMRZVrEreIfWZc8JHPLlShBAf4Nels3zLPCx6M8jOH+vuB NB3DVpsODFXu1iOo8GF94KGRQZsNx+SuH4a27dtf30+t3W7h1h4DxQHmPQ8tBnSh9Nn2ccrcnds PJ+61ctPIg5t2DlyQ9FCe6qW31Lf9KntoWLxrRkrxL61z2QYU9hoB/ostAuU= 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:b684:0:b0:679:c55a:df0b with SMTP id 006d021491bc7-6966a528262mr1726765eaf.37.1777501824660; Wed, 29 Apr 2026 15:30:24 -0700 (PDT) Date: Wed, 29 Apr 2026 15:30:24 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69f28680.050a0220.11c491.0005.GAE@google.com> Subject: [syzbot] [mm?] WARNING: lock held when returning to user space in do_fault 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: 892c894b4ba4 Merge tag 'locking-urgent-2026-04-24' of git:.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16d771ba580000 kernel config: https://syzkaller.appspot.com/x/.config?x=36f47f794f188364 dashboard link: https://syzkaller.appspot.com/bug?extid=4be30d1151ada9ad0194 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 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-892c894b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/80b0456697de/vmlinux-892c894b.xz kernel image: https://storage.googleapis.com/syzbot-assets/a3015c11e495/bzImage-892c894b.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4be30d1151ada9ad0194@syzkaller.appspotmail.com ================================================ WARNING: lock held when returning to user space! syzkaller #0 Not tainted ------------------------------------------------ dhcpcd-run-hook/5670 is leaving the kernel with locks still held! 5 locks held by dhcpcd-run-hook/5670: #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:5850 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:5884 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: do_fault+0x8b4/0x1750 mm/memory.c:6027 #1: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: filemap_map_pages+0x1c5/0x2140 mm/filemap.c:3895 #2: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290 #3: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: lruvec_stat_mod_folio+0x76/0x2b0 mm/memcontrol.c:974 #4: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: lruvec_stat_mod_folio+0x76/0x2b0 mm/memcontrol.c:974 BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:323 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5670, name: dhcpcd-run-hook preempt_count: 0, expected: 0 RCU nest depth: 5, expected: 0 INFO: lockdep is turned off. CPU: 2 UID: 0 PID: 5670 Comm: dhcpcd-run-hook 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 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 __might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9162 might_alloc include/linux/sched/mm.h:323 [inline] prepare_alloc_pages+0x44a/0x5f0 mm/page_alloc.c:4995 __alloc_frozen_pages_noprof+0x19a/0x2bc0 mm/page_alloc.c:5215 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509 vma_alloc_folio_noprof+0xed/0x1d0 mm/mempolicy.c:2544 folio_prealloc mm/memory.c:1191 [inline] alloc_anon_folio mm/memory.c:5282 [inline] do_anonymous_page+0xb46/0x2050 mm/memory.c:5376 do_pte_missing mm/memory.c:4548 [inline] handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault+0x1d2c/0x2a00 mm/memory.c:6549 handle_mm_fault+0x36d/0xa20 mm/memory.c:6718 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fe544e18d34 Code: 8d 34 19 49 39 d0 49 89 70 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 48 89 cf 4c 89 e6 48 89 4c 24 08 e8 18 c7 ff ff 48 8b RSP: 002b:00007ffcc6945410 EFLAGS: 00010206 RAX: 000000000001fe51 RBX: 0000000000000410 RCX: 0000564e7ee79db0 RDX: 0000000000000411 RSI: 0000564e7ee7a1b0 RDI: 0000000000000000 RBP: ffffffffffffffc0 R08: 00007fe544f51ac0 R09: 0000000000000410 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000400 R13: 0000000000000410 R14: 000000000000003f R15: 00007fe544f51b20 ------------[ cut here ]------------ Voluntary context switch within RCU read-side critical section! WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x859/0x19c0 kernel/rcu/tree_plugin.h:332, CPU#2: dhcpcd-run-hook/5670 Modules linked in: CPU: 2 UID: 0 PID: 5670 Comm: dhcpcd-run-hook Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:rcu_note_context_switch+0x859/0x19c0 kernel/rcu/tree_plugin.h:332 Code: c1 ea 03 80 3c 02 00 0f 85 9b 0b 00 00 48 8b 53 28 b9 01 00 00 00 4c 89 ef e8 a3 cf fe ff e9 1d f9 ff ff 48 8d 3d 17 e9 ec 0e <67> 48 0f b9 3a e9 99 f8 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8d RSP: 0000:ffffc9000333fcf0 EFLAGS: 00010006 RAX: 0000000000000005 RBX: ffff88806a63c280 RCX: ffffffff81edab71 RDX: 0000000000000000 RSI: ffffffff8c1c1c00 RDI: ffffffff90db08b0 RBP: ffff88802615ca00 R08: 0000000000000000 R09: fffffbfff21aeeaa R10: ffffffff90d77557 R11: 0000000000000014 R12: 0000000000000000 R13: ffff88802615cec4 R14: ffff88806a63b240 R15: ffffffff90d7a8e4 FS: 00007fe544cb7c80(0000) GS:ffff8880d657c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe544fd3feb CR3: 0000000038dc4000 CR4: 0000000000352ef0 Call Trace: __schedule+0x276/0x6820 kernel/sched/core.c:7043 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 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+0x359/0x790 kernel/entry/common.c:162 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0033:0x7fe544fa2f32 Code: 00 74 05 e8 c0 d6 fc ff 48 83 c4 10 5b 5d 41 5c c3 41 55 41 54 41 89 f4 55 48 89 fd 53 51 0f b6 07 48 89 f9 c1 e0 04 0f b6 11 <84> d2 74 07 48 ff c1 01 d0 eb f2 6a 1f 25 ff 7f 00 00 59 31 d2 f7 RSP: 002b:00007ffcc6944980 EFLAGS: 00000206 RAX: 000000000000076f RBX: 0000564e7ee792c0 RCX: 0000564e7ee82333 RDX: 000000000000006d RSI: 0000000000000000 RDI: 0000564e7ee82330 RBP: 0000564e7ee82330 R08: 0000000000000001 R09: 0000000000000000 R10: 00007fe544ef7fe0 R11: 00007fe544ef88e0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fe54501e240 ---------------- Code disassembly (best guess): 0: c1 ea 03 shr $0x3,%edx 3: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 7: 0f 85 9b 0b 00 00 jne 0xba8 d: 48 8b 53 28 mov 0x28(%rbx),%rdx 11: b9 01 00 00 00 mov $0x1,%ecx 16: 4c 89 ef mov %r13,%rdi 19: e8 a3 cf fe ff call 0xfffecfc1 1e: e9 1d f9 ff ff jmp 0xfffff940 23: 48 8d 3d 17 e9 ec 0e lea 0xeece917(%rip),%rdi # 0xeece941 * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: e9 99 f8 ff ff jmp 0xfffff8cd 34: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 3b: fc ff df 3e: 48 rex.W 3f: 8d .byte 0x8d --- This report is generated by a bot. 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