From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6CD7A8473; Sat, 30 Dec 2023 12:10:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SKTc4hb3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7E09C433C9; Sat, 30 Dec 2023 12:10:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1703938220; bh=qGCdGBPVvz7/vrwD9pdQbyKfPGBCZGPEuYc8oX0Cz9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SKTc4hb3euYWe2AqCtTN/jD3z01PHdAZG8+l9fO8meykD29e369FXNyDDhBCjRO0D +cnDzmIrGAc1Gc2cz98Or+lvVwzBzwPz8O3jLsOPcTmtK9g3AKg0jwwwcGgzSz2Otb HPsWLxIA9w9dEZsauElWhOJ90Z0yJajnDwKdA9JE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hyunwoo Kim , Luiz Augusto von Dentz Subject: [PATCH 6.1 072/112] Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg Date: Sat, 30 Dec 2023 11:59:45 +0000 Message-ID: <20231230115809.045659707@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231230115806.714618407@linuxfoundation.org> References: <20231230115806.714618407@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hyunwoo Kim commit 2e07e8348ea454615e268222ae3fc240421be768 upstream. This can cause a race with bt_sock_ioctl() because bt_sock_recvmsg() gets the skb from sk->sk_receive_queue and then frees it without holding lock_sock. A use-after-free for a skb occurs with the following flow. ``` bt_sock_recvmsg() -> skb_recv_datagram() -> skb_free_datagram() bt_sock_ioctl() -> skb_peek() ``` Add lock_sock to bt_sock_recvmsg() to fix this issue. Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Hyunwoo Kim Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/af_bluetooth.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -264,11 +264,14 @@ int bt_sock_recvmsg(struct socket *sock, if (flags & MSG_OOB) return -EOPNOTSUPP; + lock_sock(sk); + skb = skb_recv_datagram(sk, flags, &err); if (!skb) { if (sk->sk_shutdown & RCV_SHUTDOWN) - return 0; + err = 0; + release_sock(sk); return err; } @@ -294,6 +297,8 @@ int bt_sock_recvmsg(struct socket *sock, skb_free_datagram(sk, skb); + release_sock(sk); + if (flags & MSG_TRUNC) copied = skblen;