From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi2-f4.google.com (mail-oi2-f4.google.com [74.125.231.196]) (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 0B660339705 for ; Sun, 30 Aug 2026 11:40:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.196 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788090036; cv=none; b=mt9RQzB5jTgE1WHGvicHmhGDNvbyN/6h2WYNJJ5byFsiWd4NzKyxTXzKtt5eFC7PQTRemxDOYWvMQzvmomXikhNt35tnv6DiO/5xhfOrBpC+JplxO/FZudtd7LWd4RAqHkA/sBWR8zIpj5bllc4tnOIy058W/A8MHpj4L2k62W8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788090036; c=relaxed/simple; bh=8Pff1Wk07M/7bubMolJQjCm0CW3UdfouL21G/Pknu+4=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=Ra8v18zzIo8zSGlr+FVSah4PEEO4D+5L83lgqrBj2OyuOzK89kUfnn1v0sN8oxsfI6/ujafIJtwRk71G2zoaHbF7ctGv167Jz4i/T9TdBhLonNCjJujel5ckS5SmnRIpiuRtUme59YlSiurQrl1dKIvY7gknzvvPH60EiAh+Ijs= 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=74.125.231.196 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-oi2-f4.google.com with SMTP id 5614622812f47-4b3880be385so1111418b6e.0 for ; Sun, 30 Aug 2026 04:40:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788090034; x=1788694834; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=e2vCjviBcI/2k6EmDCZf+Wibzyyve/QshLja8u6lGI4=; b=NPHt8SR46q2me9uXOMsWPEfJUVUhzAWGPXm0cgOlazS2u5dQ7ixSxePkc9AC59j4mX hRVzzVqlUJTrt6gm1PkvweMnIHj25nzcbv7o0dZ3AqZ0P27QyQ/KK64hnv8pbEoOaDL3 XfiJRXoZtAxqAVAIPsHbzmmSG/ItqOynCBLJBI+OTGp6p+uaiPFR2tK2f8XwHhoLR+x9 FGGcP62697jzK3D5H8NlyrTuA2VmArVy1bmNx5T8WrhN3nwGW2LNNdrpsxDVRt5mm+jN 6F56tBTa+X8GXKETYeSmAcnH4tZJnPC+KnWAthOGlAlG7DDyt2cIuWHPWqeVAUgxLKyW lM2Q== X-Forwarded-Encrypted: i=1; AHgh+RrFVgrL/aKsBT6JaMS9wXiV9ZeAP6FFX1LPAB0WYzqm/jetf5x05bJzlEcxXWlTCJi18/1Se9RANcPdXrU=@vger.kernel.org X-Gm-Message-State: AFuF++kIAN2Ak0IrCAr7DgJ0Od6vz9SRK3isw4fforuSJTQsu+7ZkDUw FKNWCaBwYtmC5owmO+Z6nBQFcMRP6pagkkIBFuMH04jlSnV/UEBmf4Khhl9dua/2WYAoat1Dklf OJ7wwabu/6TCsLkns5v02YFPzfeygkd/Ufa5GnfH+vQjBST4vhMnWqbUDLaw= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1523:b0:496:892:c58f with SMTP id 5614622812f47-4b398037ce5mr15499585b6e.2.1788090033902; Sun, 30 Aug 2026 04:40:33 -0700 (PDT) Date: Sun, 30 Aug 2026 04:40:33 -0700 In-Reply-To: <6a8725d5.4d75e56a.c9a88.0043.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a9416b1.a8e469d2.cbf3.5607.GAE@google.com> Subject: Re: [syzbot] [media?] KASAN: slab-use-after-free Read in __vb2_queue_cancel (2) From: syzbot To: dmantipov@yandex.ru, hverkuil@kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, lvc-project@linuxtesting.org, m.szyprowski@samsung.com, mchehab@kernel.org, syzkaller-bugs@googlegroups.com, tfiga@chromium.org Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 08dbfad3f504 Merge tag 'for-linus' of git://git.kernel.org.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=11740349580000 kernel config: https://syzkaller.appspot.com/x/.config?x=19560cab9a915237 dashboard link: https://syzkaller.appspot.com/bug?extid=dd0f06181ab66b93dc00 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c45d79580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10eeee25580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/5896a88f5701/disk-08dbfad3.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/af401a4b0127/vmlinux-08dbfad3.xz kernel image: https://storage.googleapis.com/syzbot-assets/c322757c580c/bzImage-08dbfad3.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+dd0f06181ab66b93dc00@syzkaller.appspotmail.com ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 25 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Workqueue: events request_module_async RIP: 0010:__wake_up_common+0x9b/0x1f0 kernel/sched/wait.c:105 Code: 02 00 0f 85 5b 01 00 00 48 8b 5b 40 48 8d 43 e8 4c 39 fb 0f 84 b3 00 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 d9 48 c1 e9 03 <80> 3c 11 00 0f 85 18 01 00 00 48 bd 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffffc900001f79a0 EFLAGS: 00010056 RAX: ffffffffffffffe8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff8880298b5790 RBP: ffff8880298b5790 R08: 0000000000000000 R09: fffff5200003ef2b R10: 0000000000000003 R11: 00000000000075fb R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880298b57d0 FS: 0000000000000000(0000) GS:ffff888123c61000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557902ace698 CR3: 0000000034273000 CR4: 0000000000350ef0 Call Trace: __wake_up_common_lock kernel/sched/wait.c:126 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:147 __vb2_queue_cancel+0x348/0xe90 drivers/media/common/videobuf2/videobuf2-core.c:2244 vb2_core_queue_release+0x27/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2677 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:943 [inline] vb2_video_unregister_device drivers/media/common/videobuf2/videobuf2-v4l2.c:1279 [inline] vb2_video_unregister_device+0x152/0x2e0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1254 em28xx_v4l2_init.cold+0xe1a/0x3a18 drivers/media/usb/em28xx/em28xx-video.c:3097 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1248 request_module_async+0x1e/0x30 drivers/media/usb/em28xx/em28xx-cards.c:3685 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387 process_scheduled_works kernel/workqueue.c:3470 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__wake_up_common+0x9b/0x1f0 kernel/sched/wait.c:105 Code: 02 00 0f 85 5b 01 00 00 48 8b 5b 40 48 8d 43 e8 4c 39 fb 0f 84 b3 00 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 d9 48 c1 e9 03 <80> 3c 11 00 0f 85 18 01 00 00 48 bd 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffffc900001f79a0 EFLAGS: 00010056 RAX: ffffffffffffffe8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff8880298b5790 RBP: ffff8880298b5790 R08: 0000000000000000 R09: fffff5200003ef2b R10: 0000000000000003 R11: 00000000000075fb R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880298b57d0 FS: 0000000000000000(0000) GS:ffff888123c61000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557902ace698 CR3: 0000000034273000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 02 00 add (%rax),%al 2: 0f 85 5b 01 00 00 jne 0x163 8: 48 8b 5b 40 mov 0x40(%rbx),%rbx c: 48 8d 43 e8 lea -0x18(%rbx),%rax 10: 4c 39 fb cmp %r15,%rbx 13: 0f 84 b3 00 00 00 je 0xcc 19: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 20: fc ff df 23: 48 89 d9 mov %rbx,%rcx 26: 48 c1 e9 03 shr $0x3,%rcx * 2a: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) <-- trapping instruction 2e: 0f 85 18 01 00 00 jne 0x14c 34: 48 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%rbp 3b: fc ff df 3e: 4c rex.WR 3f: 8b .byte 0x8b --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.