From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from r3-19.sinamail.sina.com.cn (r3-19.sinamail.sina.com.cn [202.108.3.19]) (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 617EA1DFDA1 for ; Mon, 23 Feb 2026 04:07:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.108.3.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771819626; cv=none; b=AGuvVVbzkkfCeuX7Nl86HvRONI78J3cAnRzUexvuAR2zv8MNIts+J/S0dc2UUBZpazvGSlX0m1pOD/mGUWp1ks4gNnq0VEygooKJzRGYaIrKyGxSJUmkwkO8IuIpnSdkj2o2qf+KC7SobWrJasZdmQT8dLhLT2pzI3b65xU/2Ig= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771819626; c=relaxed/simple; bh=Pf+a34ilZvSK5wJQ+xgVlpkuImKP3hm1Pdiuri2y7CI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JTr5pzlXXPa+JgBk5MALjoXHczM5GF8XaA48UkYCZrQpn8dtomtG7Q9gBQ1MIwRmyntiUlzR38g6TkrHfi5fJy42P9YGbvIKii671yQzKIwFtGXn+2CR5c0ejCP86h3nv2N1+cFmsMmKu1AyYluHOsnK54Vh9iHIya69ptck8FA= 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=sZpYqwHh; arc=none smtp.client-ip=202.108.3.19 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="sZpYqwHh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1771819622; bh=9cpdWqTERl3bopN1O9MO8wHekB8QovMGQy3RoVioFyQ=; h=From:Subject:Date:Message-ID; b=sZpYqwHhOUmn6SSBMnAZfbRCo1pyDCu2OkMAUPw82RbqwBRZeat6b6CdqExfRsta3 v4YyfQShXLAMEX1Nl7CTrZOj8ualpQuTSQyb1bZcnptbpAvfl2r0/+CMpCoNfL6rTx RR1U4z15IGVSDg9aYM+qvyL7cHijja5OgPoMH+zY= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.62.144]) by sina.com (10.54.253.32) with ESMTP id 699BD2380000318C; Mon, 23 Feb 2026 12:06:17 +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: 4453654456618 X-SMAIL-UIID: 7D85D7FEA9BF4B93888C258905B08193-20260223-120617-1 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 dvb_frontend_release (3) Date: Mon, 23 Feb 2026 12:06:08 +0800 Message-ID: <20260223040609.3396-1-hdanton@sina.com> In-Reply-To: <6992e4aa.a70a0220.2c38d7.00e9.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: Mon, 16 Feb 2026 01:34:34 -0800 [thread overview] > syzbot has found a reproducer for the following issue on: > > HEAD commit: c22e26bd0906 Merge tag 'landlock-7.0-rc1' of git://git.ker.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=16bcf6e6580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6428d17febdfb14e > dashboard link: https://syzkaller.appspot.com/bug?extid=ae466a728017ec940b41 > compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ce3652580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1121515a580000 #syz test --- x/drivers/media/dvb-core/dvb_frontend.c +++ y/drivers/media/dvb-core/dvb_frontend.c @@ -2836,6 +2836,7 @@ static int dvb_frontend_open(struct inod if ((ret = dvb_generic_open(inode, file)) < 0) goto err1; + dvb_device_get(dvbdev); if ((file->f_flags & O_ACCMODE) != O_RDONLY) { /* normal tune mode when opened R/W */ @@ -3077,7 +3078,8 @@ int dvb_unregister_frontend(struct dvb_f mutex_lock(&frontend_mutex); dvb_frontend_stop(fe); - dvb_remove_device(fepriv->dvbdev); + dvb_unregister_device(fepriv->dvbdev); + fepriv->dvbdev = NULL; /* fe is invalid now */ mutex_unlock(&frontend_mutex); --