net/ipv4: Revert use of struct_size() helper

Revert the use of structr_size() and stay with IP_MSFILTER_SIZE() for
now, as in this case, the size of struct ip_msfilter didn't change with
the addition of the flexible array imsf_slist_flex[]. So, if we use
struct_size() we will be allocating and calculating the size of
struct ip_msfilter with one too many items for imsf_slist_flex[].

We might use struct_size() in the future, but for now let's stay
with IP_MSFILTER_SIZE().

Fixes: 	2d3e5caf96b9 ("net/ipv4: Replace one-element array with flexible-array member")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index a5f4ecb..c2d477e 100644 (file)
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2553,8 +2553,8 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
        copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
        len = flex_array_size(psl, sl_addr, copycount);
        msf->imsf_numsrc = count;
-       if (put_user(struct_size(optval, imsf_slist_flex, copycount), optlen) ||
-           copy_to_user(optval, msf, struct_size(optval, imsf_slist_flex, 0))) {
+       if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
+           copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
                return -EFAULT;
        }
        if (len &&

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index bbe660b..468969c 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -667,7 +667,7 @@ static int set_mcast_msfilter(struct sock *sk, int ifindex,
        struct sockaddr_in *psin;
        int err, i;
 
-       msf = kmalloc(struct_size(msf, imsf_slist_flex, numsrc), GFP_KERNEL);
+       msf = kmalloc(IP_MSFILTER_SIZE(numsrc), GFP_KERNEL);
        if (!msf)
                return -ENOBUFS;
 
@@ -1228,7 +1228,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname,
        {
                struct ip_msfilter *msf;
 
-               if (optlen < struct_size(msf, imsf_slist_flex, 0))
+               if (optlen < IP_MSFILTER_SIZE(0))
                        goto e_inval;
                if (optlen > sysctl_optmem_max) {
                        err = -ENOBUFS;
@@ -1246,8 +1246,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname,
                        err = -ENOBUFS;
                        break;
                }
-               if (struct_size(msf, imsf_slist_flex, msf->imsf_numsrc) >
-                   optlen) {
+               if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
                        kfree(msf);
                        err = -EINVAL;
                        break;
@@ -1660,12 +1659,11 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
        {
                struct ip_msfilter msf;
 
-               if (len < struct_size(&msf, imsf_slist_flex, 0)) {
+               if (len < IP_MSFILTER_SIZE(0)) {
                        err = -EINVAL;
                        goto out;
                }
-               if (copy_from_user(&msf, optval,
-                                  struct_size(&msf, imsf_slist_flex, 0))) {
+               if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
                        err = -EFAULT;
                        goto out;
                }