net: ipv6: Use struct_size() helper and kcalloc()

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes. Also, remove unnecessary
function ipv6_rpl_srh_alloc_size() and replace kzalloc() with kcalloc(),
which has a 2-factor argument form for multiplication.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/rpl.h b/include/net/rpl.h
index dceff60..308ef0a 100644 (file)
--- a/include/net/rpl.h
+++ b/include/net/rpl.h
@@ -26,12 +26,6 @@ static inline void rpl_exit(void) {}
 /* Worst decompression memory usage ipv6 address (16) + pad 7 */
 #define IPV6_RPL_SRH_WORST_SWAP_SIZE (sizeof(struct in6_addr) + 7)
 
-static inline size_t ipv6_rpl_srh_alloc_size(unsigned char n)
-{
-       return sizeof(struct ipv6_rpl_sr_hdr) +
-               ((n + 1) * sizeof(struct in6_addr));
-}
-
 size_t ipv6_rpl_srh_size(unsigned char n, unsigned char cmpri,
                         unsigned char cmpre);
 

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 5a8bbcd..e9b3669 100644 (file)
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -580,7 +580,7 @@ looped_back:
        hdr->segments_left--;
        i = n - hdr->segments_left;
 
-       buf = kzalloc(ipv6_rpl_srh_alloc_size(n + 1) * 2, GFP_ATOMIC);
+       buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC);
        if (unlikely(!buf)) {
                kfree_skb(skb);
                return -1;

diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c
index c3ececd..5fdf3eb 100644 (file)
--- a/net/ipv6/rpl_iptunnel.c
+++ b/net/ipv6/rpl_iptunnel.c
@@ -136,8 +136,7 @@ static int rpl_do_srh_inline(struct sk_buff *skb, const struct rpl_lwt *rlwt,
 
        oldhdr = ipv6_hdr(skb);
 
-       buf = kzalloc(ipv6_rpl_srh_alloc_size(srh->segments_left - 1) * 2,
-                     GFP_ATOMIC);
+       buf = kcalloc(struct_size(srh, segments.addr, srh->segments_left), 2, GFP_ATOMIC);
        if (!buf)
                return -ENOMEM;