svcrpc: fix handling of too-short rpc's
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.
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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 @@
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 @@
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;
