From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out203-205-251-59.mail.qq.com (out203-205-251-59.mail.qq.com [203.205.251.59]) (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 737D614F9FA for ; Tue, 11 Jun 2024 02:34:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.205.251.59 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718073294; cv=none; b=e9Q4R7oX4d5M4apWsNb3cg7hv2kbVcv2BB0ojbKTiy0HtMx2KLmbioJ/IonTuOs+dOBj06u+WqWXOC2lmXFYw0SCC+TwoAf35udHg5CcGqcZsynTCs3Xt3h9B06Pk6rSXNgJU1rhr6mhR9PYMT47LrRGd1IqkCgYRTSRmuCUsO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718073294; c=relaxed/simple; bh=KnAmKro879fRFq+RiQ5LefGpzSwBeLfGvMuFjATxW2E=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=gFmmWNXwQMP1NQCpWENfSh3XBWvTcdzbB51n2gICT/4TuvVfaXwpW2xuhRuUcKGqwVWPFFUCQpIM+eUA7b0Mn0zWUeXp8heEQ03pFkIYPoVmssDOfSFLnbALZXqt93jcsDKkg+PuVp1WBnnofzXCJWPVbshoBMYd/sStrjGzfek= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=d4CCwgxD; arc=none smtp.client-ip=203.205.251.59 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="d4CCwgxD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1718073285; bh=RqDYlNEj89LVooht78uM6N9w3lcGxiYS1Vsrlw1PlCQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=d4CCwgxDBm2ARJXRMLW+zBIMvfgFdxQB0sKXvu6gRqe5YPgzO5wGisuDIpsWb8z2z dSaGM1wKGi+Ir3XvlZh4NQVFJ/Q4JMaLAcaQyQNGJAsgPdzv5j8BXnpbfGsschBkof Cb/II2bJehaO/bhCxdjspoq2I+MbSC+EPASa8IvQ= Received: from pek-lxu-l1.wrs.com ([111.198.228.153]) by newxmesmtplogicsvrszb9-1.qq.com (NewEsmtp) with SMTP id 7209947C; Tue, 11 Jun 2024 10:28:32 +0800 X-QQ-mid: xmsmtpt1718072912tb3d1endf Message-ID: X-QQ-XMAILINFO: N7/wgsuYk0Vx7zKEW34DSnHyfNSWFmm4pwThrtf0saieUV8rdGNVzRA/u/Etfi reQ+rVGrftYSvNnCjhcZj1o6m5Oa6vCRshwAyACiLFp8UWB/L+jO/rVd2Ur6zJOR9RxXtYyG+3SN mTn9o6Exo7IdrgWup4oCg7AhNpBBIKFDBjfN2owJb610sTtE6rv5Hyi3bTmxAdenI7i8a5MKQC1l 9eaFvjy8ED72h90jQ0HIqHKFMM076kdtsM7uDb+/GC6DG2uwcVKBpihXBDgoo8vKEB29IdNQ7rKo Pm3eaT+SOBL0RF3GdRRjUK0DTtIMzdIX4Mx7z8QkLZNyfHCAVQJknjwvxvhkepDoRsFPvTJG+sF5 nPB44nYE1QYLfIbZzVYIn9TyGk6EaFwDiHxQxgaS+1I735twTuyim8jQ8VmR8pN05IckY+bTcp4H 4IgSkJLh04tR4nP0YgOkf6JIjPC0XeiM1GLnblQEkk0JHkKAQYhZpKXx92jzUOI2qtoBRfaLzjSh w4HR3JgLEUmiKuOV4+KGryumlTUPd+XmW01LclCr02Y1CIeIDfR7uAYEnkHuDPy6RQ26L6Wr2pyN o3mox7VCN9SUFag8G96RzhVJfAySxt8qOOoFNAylVoHa/SNC/EgqriuKYF/vUZweqkXFAixxtE0x ust1h0bya1x9x2qn9Dn3CGtdASwbBbzA3iMceMdaLObrDchoeIRdfOO1irqZ7a7V6OWe8aMzmQH5 iF8FmP1NkUnfQ+0CEMdU43hzZZs1QO409UkllmGpujcmVnI/GsQqmdJu1JRwzInNymUwj4B0oYt5 rIS0cICv/5P+mW4ejGzO04HBszqCRtu3b+Tuo1xz7laTodnh+QXwNbj3fi3Vfmhks2MRv2a4PCaO l4CLhKl3L5Z44YWeb7AeYUxbthEcx7WEqQoQkPE+4tvgfJh7SAowhvMbMRwvATgA== X-QQ-XMRINFO: NyFYKkN4Ny6FSmKK/uo/jdU= From: Edward Adam Davis To: syzbot+b7f6f8c9303466e16c8a@syzkaller.appspotmail.com Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [bluetooth?] general protection fault in l2cap_sock_recv_cb Date: Tue, 11 Jun 2024 10:28:33 +0800 X-OQ-MSGID: <20240611022832.1419703-2-eadavis@qq.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <000000000000b0906d061a468b93@google.com> References: <000000000000b0906d061a468b93@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit please test null ptr defref in l2cap_sock_recv_cb #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git cc8ed4d0a848 diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 6db60946c627..6f01920586e6 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1486,6 +1486,8 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) int err; lock_sock(sk); + l2cap_chan_hold(chan); + l2cap_chan_lock(chan); if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { err = -ENOMEM; @@ -1534,6 +1536,8 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) } done: + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); release_sock(sk); return err;