diff options
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 3c2c6cd3933b..e3703a3e7ef4 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -1473,19 +1473,28 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, } case MCAST_MSFILTER: { + struct group_filter __user *p = (void __user *)optval; struct group_filter gsf; + const int size0 = offsetof(struct group_filter, gf_slist); + int num; - if (len < GROUP_FILTER_SIZE(0)) { + if (len < size0) { err = -EINVAL; goto out; } - if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) { + if (copy_from_user(&gsf, p, size0)) { err = -EFAULT; goto out; } - err = ip_mc_gsfget(sk, &gsf, - (struct group_filter __user *)optval, - optlen); + num = gsf.gf_numsrc; + err = ip_mc_gsfget(sk, &gsf, p->gf_slist); + if (err) + goto out; + if (gsf.gf_numsrc < num) + num = gsf.gf_numsrc; + if (put_user(GROUP_FILTER_SIZE(num), optlen) || + copy_to_user(p, &gsf, size0)) + err = -EFAULT; goto out; } case IP_MULTICAST_ALL: |