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 EB9738820 for ; Fri, 10 Mar 2023 14:49:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50D50C433A0; Fri, 10 Mar 2023 14:49:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678459799; bh=L2uJOXxEWV1oeghzGK5EbVRqHOG3cTaX2sl36wGJmow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cixh2baLRbPGSClc9w20ZjcUILh2FKxD1wyuw4DciR/AQkzJHz1cAuoRD4rq6Klfn 0aYm/xtS9C56uBqmvuIao8JKsedfo4I+L3w2tXl1bPT0LLniyLT8qiQ2h3GDbzrgzG fbeBjzYlnKUaKQf/fXf7cYbUY1hTD4KJ9rcrKINA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pietro Borrello , Eric Dumazet , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 124/529] tap: tap_open(): correctly initialize socket uid Date: Fri, 10 Mar 2023 14:34:27 +0100 Message-Id: <20230310133810.728311637@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133804.978589368@linuxfoundation.org> References: <20230310133804.978589368@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Pietro Borrello [ Upstream commit 66b2c338adce580dfce2199591e65e2bab889cff ] sock_init_data() assumes that the `struct socket` passed in input is contained in a `struct socket_alloc` allocated with sock_alloc(). However, tap_open() passes a `struct socket` embedded in a `struct tap_queue` allocated with sk_alloc(). This causes a type confusion when issuing a container_of() with SOCK_INODE() in sock_init_data() which results in assigning a wrong sk_uid to the `struct sock` in input. On default configuration, the type confused field overlaps with padding bytes between `int vnet_hdr_sz` and `struct tap_dev __rcu *tap` in `struct tap_queue`, which makes the uid of all tap sockets 0, i.e., the root one. Fix the assignment by using sock_init_data_uid(). Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") Signed-off-by: Pietro Borrello Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/tap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 8f7bb15206e9f..d9018d9fe3106 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -523,7 +523,7 @@ static int tap_open(struct inode *inode, struct file *file) q->sock.state = SS_CONNECTED; q->sock.file = file; q->sock.ops = &tap_socket_ops; - sock_init_data(&q->sock, &q->sk); + sock_init_data_uid(&q->sock, &q->sk, inode->i_uid); q->sk.sk_write_space = tap_sock_write_space; q->sk.sk_destruct = tap_sock_destruct; q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; -- 2.39.2