Re: [PATCH] sctp: fix memory leak in sctp_datamsg_from_user() when copy from user space fails
From: Vlad Yasevich <hidden>
Date: 2012-11-27 14:49:25
Also in:
linux-sctp
On 11/27/2012 09:01 AM, Tommi Rantala wrote:
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 <redacted>Acked-by: Vlad Yasevich <redacted> -vlad
quoted hunk ↗ jump to hunk
--- net/sctp/chunk.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index 7c2df9c..f2aebdb 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c@@ -284,7 +284,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, 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_user(struct sctp_association *asoc, __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_user(struct sctp_association *asoc, return msg; +errout_chunk_free: + sctp_chunk_free(chunk); + errout: list_for_each_safe(pos, temp, &msg->chunks) { list_del_init(pos);