linux-kernel - [ 04/80] sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscall

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20130109201500.946402656@linuxfoundation.org>
Date:	Wed,  9 Jan 2013 12:34:56 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	alan@...rguk.ukuu.org.uk, Tommi Rantala <tt.rantala@...il.com>,
	Vlad Yasevich <vyasevich@...il.com>,
	Neil Horman <nhorman@...driver.com>,
	"David S. Miller" <davem@...emloft.net>
Subject: [ 04/80] sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscall

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Tommi Rantala <tt.rantala@...il.com>

[ Upstream commit 6e51fe7572590d8d86e93b547fab6693d305fd0d ]

Consider the following program, that sets the second argument to the
sendto() syscall incorrectly:

 #include <string.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>

 int main(void)
 {
         int fd;
         struct sockaddr_in sa;

         fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/);
         if (fd < 0)
                 return 1;

         memset(&sa, 0, sizeof(sa));
         sa.sin_family = AF_INET;
         sa.sin_addr.s_addr = inet_addr("127.0.0.1");
         sa.sin_port = htons(11111);

         sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa));

         return 0;
 }

We get -ENOMEM:

 $ strace -e sendto ./demo
 sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 ENOMEM (Cannot allocate memory)

Propagate the error code from sctp_user_addto_chunk(), so that we will
tell user space what actually went wrong:

 $ strace -e sendto ./demo
 sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EFAULT (Bad address)

Noticed while running Trinity (the syscall fuzzer).

Signed-off-by: Tommi Rantala <tt.rantala@...il.com>
Acked-by: Vlad Yasevich <vyasevich@...il.com>
Acked-by: Neil Horman <nhorman@...driver.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/sctp/chunk.c  |   13 +++++++++----
 net/sctp/socket.c |    4 ++--
 2 files changed, 11 insertions(+), 6 deletions(-)

--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -183,7 +183,7 @@ struct sctp_datamsg *sctp_datamsg_from_u
 
 	msg = sctp_datamsg_new(GFP_KERNEL);
 	if (!msg)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	/* Note: Calculate this outside of the loop, so that all fragments
 	 * have the same expiration.
@@ -280,8 +280,11 @@ struct sctp_datamsg *sctp_datamsg_from_u
 
 		chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
 
-		if (!chunk)
+		if (!chunk) {
+			err = -ENOMEM;
 			goto errout;
+		}
+
 		err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
 		if (err < 0)
 			goto errout_chunk_free;
@@ -315,8 +318,10 @@ struct sctp_datamsg *sctp_datamsg_from_u
 
 		chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
 
-		if (!chunk)
+		if (!chunk) {
+			err = -ENOMEM;
 			goto errout;
+		}
 
 		err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov);
 
@@ -342,7 +347,7 @@ errout:
 		sctp_chunk_free(chunk);
 	}
 	sctp_datamsg_put(msg);
-	return NULL;
+	return ERR_PTR(err);
 }
 
 /* Check whether this message has expired. */
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1908,8 +1908,8 @@ SCTP_STATIC int sctp_sendmsg(struct kioc
 
 	/* Break the message into multiple chunks of maximum size. */
 	datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len);
-	if (!datamsg) {
-		err = -ENOMEM;
+	if (IS_ERR(datamsg)) {
+		err = PTR_ERR(datamsg);
 		goto out_free;
 	}
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/