[ 03/80] sctp: fix memory leak in sctp_datamsg_from_user() when copy from user space fails

Greg Kroah-Hartman
2013-01-09T21:56:29Z

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

[ Upstream commit be364c8c0f17a3dd42707b5a090b318028538eb9 ]

Trinity (the syscall fuzzer) discovered a memory leak in SCTP,
reproducible e.g. with the sendto() syscall by passing invalid
user space pointer in the second argument:

#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;
}

As far as I can tell, the leak has been around since ~2003.

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sctp/chunk.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -284,7 +284,7 @@ struct sctp_datamsg *sctp_datamsg_from_u
goto errout;
err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
if (err < 0)
- goto errout;
+ goto errout_chunk_free;

offset += len;

@@ -324,7 +324,7 @@ struct sctp_datamsg *sctp_datamsg_from_u
__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
- (__u8 *)chunk->skb->data);
if (err < 0)
- goto errout;
+ goto errout_chunk_free;

sctp_datamsg_assign(msg, chunk);
list_add_tail(&chunk->frag_list, &msg->chunks);
@@ -332,6 +332,9 @@ struct sctp_datamsg *sctp_datamsg_from_u

return msg;

+errout_chunk_free:
+ sctp_chunk_free(chunk);
+
errout:
list_for_each_safe(pos, temp, &msg->chunks) {
list_del_init(pos);