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

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

From: "J. Bruce Fields" <bfie...@redhat.com>

commit cf3aa02cb4a0c5af5557dd47f15a08a7df33182a upstream.

If we detect that an rpc is too short, we abort and close the
connection.  Except, there's a bug here: we're leaving sk_datalen
nonzero without leaving any pages in the sk_pages array.  The most
likely result of the inconsistency is a subsequent crash in
svc_tcp_clear_pages.

Also demote the BUG_ON in svc_tcp_clear_pages to a WARN.

Signed-off-by: J. Bruce Fields <bfie...@redhat.com>
Signed-off-by: Kamal Mostafa <ka...@canonical.com>
---
 net/sunrpc/svcsock.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 0f679df..df74919 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -917,7 +917,10 @@ static void svc_tcp_clear_pages(struct svc_sock *svsk)
        len = svsk->sk_datalen;
        npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
        for (i = 0; i < npages; i++) {
-               BUG_ON(svsk->sk_pages[i] == NULL);
+               if (svsk->sk_pages[i] == NULL) {
+                       WARN_ON_ONCE(1);
+                       continue;
+               }
                put_page(svsk->sk_pages[i]);
                svsk->sk_pages[i] = NULL;
        }
@@ -1092,8 +1095,10 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
                goto err_noclose;
        }
 
-       if (svc_sock_reclen(svsk) < 8)
+       if (svc_sock_reclen(svsk) < 8) {
+               svsk->sk_datalen = 0;
                goto err_delete; /* client is nuts. */
+       }
 
        rqstp->rq_arg.len = svsk->sk_datalen;
        rqstp->rq_arg.page_base = 0;
-- 
1.8.1.2

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

Reply via email to