[SUNRPC]: Make sure on-stack cmsg buffer is properly aligned.

Based upon a report from Meelis Roos.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 593f62ff8521e1f502f7af6ea68cccd39a7b68fa..2772fee93881f1fc85d5e8a56b7a31fa3e1c5cca 100644 (file)
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -452,6 +452,8 @@ union svc_pktinfo_u {
        struct in_pktinfo pkti;
        struct in6_pktinfo pkti6;
 };
+#define SVC_PKTINFO_SPACE \
+       CMSG_SPACE(sizeof(union svc_pktinfo_u))
 
 static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
 {
@@ -491,8 +493,11 @@ svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
        struct svc_sock *svsk = rqstp->rq_sock;
        struct socket   *sock = svsk->sk_sock;
        int             slen;
-       char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
-       struct cmsghdr *cmh = (struct cmsghdr *)buffer;
+       union {
+               struct cmsghdr  hdr;
+               long            all[SVC_PKTINFO_SPACE / sizeof(long)];
+       } buffer;
+       struct cmsghdr *cmh = &buffer.hdr;
        int             len = 0;
        int             result;
        int             size;
@@ -745,8 +750,11 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
        struct svc_sock *svsk = rqstp->rq_sock;
        struct svc_serv *serv = svsk->sk_server;
        struct sk_buff  *skb;
-       char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
-       struct cmsghdr *cmh = (struct cmsghdr *)buffer;
+       union {
+               struct cmsghdr  hdr;
+               long            all[SVC_PKTINFO_SPACE / sizeof(long)];
+       } buffer;
+       struct cmsghdr *cmh = &buffer.hdr;
        int             err, len;
        struct msghdr msg = {
                .msg_name = svc_addr(rqstp),