From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from r3-25.sinamail.sina.com.cn (r3-25.sinamail.sina.com.cn [202.108.3.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C091500947 for ; Sat, 10 Jan 2026 08:50:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.108.3.25 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768035055; cv=none; b=cDevSYdDGPr84eKKPgTTtf9Er4irJoPTCLRAl+eLJNPsr/k3zXhZZ+ti6yd0akiiqVoui1QgFSQ0+KBB19O0a+adyQ5KfsbKedubiTvPdN39Zu3VrZKgyLf8BtSjroA9/0nYv5DiVaWuYP6LnASTcLtHSTkAlbg3ezpe5Owa3y4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768035055; c=relaxed/simple; bh=E6d+LzsruTBbsgQZJa6Lrr0Y6TWuJ1GL1aCLvMycjuA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=acsZbRg7sm8e3CYrRYsSTQdMuYKk4PH1OA53q/EvVzSvkACbxsQiOuPMy4XQyzcH3W7ugVrfm2tVeTAkJ5EkjSQV5Vn0CAho4sPXzdifeIH7RP150MZFJZV8hovkJvC7dcU/jtDGvVXCoEzelbfZXu0GKo6rrLoNInGDRFqQ2+o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=PWGS11oE; arc=none smtp.client-ip=202.108.3.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="PWGS11oE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1768035051; bh=bCI2AOcSJ7J693TQB5PSBu5VdI/Hxm1XnfPcuAwkNYg=; h=From:Subject:Date:Message-ID; b=PWGS11oEw9sEbNh3/GYcp1WABwtrIdVt/yQ9YX71SumGduZof+KvfHjeTC5lLYP/F 4jp1iYtD/JIxDnRYcJNRX9vIuB7EIYKg1PEgzDQDaZqlniVWxWOAB2k20RBPk8GAwX u3Us/He/E7K/GUQjB7sOCzMANFLCHbFpNXaiiAAM= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.57.85]) by sina.com (10.54.253.31) with ESMTP id 696212DE000073C1; Sat, 10 Jan 2026 16:50:41 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 3388606816036 X-SMAIL-UIID: CC4B2831DB174295B6B474910E96DB1C-20260110-165041-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [media?] KASAN: slab-use-after-free Read in em28xx_release_resources Date: Sat, 10 Jan 2026 16:50:29 +0800 Message-ID: <20260110085030.2131-1-hdanton@sina.com> In-Reply-To: <69608280.050a0220.1c677c.03b0.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Date: Thu, 08 Jan 2026 20:22:24 -0800 > syzbot has found a reproducer for the following issue on: > > HEAD commit: 79b95d74470d Merge tag 'hid-for-linus-2026010801' of git:/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=112b219a580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a94030c847137a18 > dashboard link: https://syzkaller.appspot.com/bug?extid=16062f26c6480975e5ed > compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=152b219a580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13e6e922580000 #syz test --- x/drivers/media/usb/em28xx/em28xx-video.c +++ y/drivers/media/usb/em28xx/em28xx-video.c @@ -2150,6 +2150,10 @@ static int em28xx_v4l2_open(struct file if (mutex_lock_interruptible(&dev->lock)) return -ERESTARTSYS; + if (dev->v4l2 == NULL) { + mutex_unlock(&dev->lock); + return -EINVAL; + } ret = v4l2_fh_open(filp); if (ret) { dev_err(&dev->intf->dev, @@ -2898,6 +2902,7 @@ unregister_dev: v4l2_device_unregister(&v4l2->v4l2_dev); err: dev->v4l2 = NULL; + em28xx_v4l2_media_release(dev); kref_put(&v4l2->ref, em28xx_free_v4l2); mutex_unlock(&dev->lock); return ret; --