From 168a2cca81438aef819e43feb161614488dee97b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 30 Mar 2020 16:40:04 -0400 Subject: [PATCH] ipv6: do compat setsockopt for MCAST_MSFILTER directly similar to the ipv4 counterpart of that patch - the same trick used to align the tail array properly. Signed-off-by: Al Viro --- net/ipv6/ipv6_sockglue.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 7d3ecc0..2b5029d 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -980,9 +980,55 @@ int compat_ipv6_setsockopt(struct sock *sk, int level, int optname, case MCAST_LEAVE_SOURCE_GROUP: case MCAST_BLOCK_SOURCE: case MCAST_UNBLOCK_SOURCE: - case MCAST_MSFILTER: return compat_mc_setsockopt(sk, level, optname, optval, optlen, ipv6_setsockopt); + case MCAST_MSFILTER: + { + const int size0 = offsetof(struct compat_group_filter, gf_slist); + struct compat_group_filter *gf32; + void *p; + int n; + + if (optlen < size0) + return -EINVAL; + if (optlen > sysctl_optmem_max - 4) + return -ENOBUFS; + + p = kmalloc(optlen + 4, GFP_KERNEL); + if (!p) + return -ENOMEM; + + gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */ + if (copy_from_user(gf32, optval, optlen)) { + err = -EFAULT; + goto mc_msf_out; + } + + n = gf32->gf_numsrc; + /* numsrc >= (4G-140)/128 overflow in 32 bits */ + if (n >= 0x1ffffffU || + n > sysctl_mld_max_msf) { + err = -ENOBUFS; + goto mc_msf_out; + } + if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen) { + err = -EINVAL; + goto mc_msf_out; + } + + rtnl_lock(); + lock_sock(sk); + err = ip6_mc_msfilter(sk, &(struct group_filter){ + .gf_interface = gf32->gf_interface, + .gf_group = gf32->gf_group, + .gf_fmode = gf32->gf_fmode, + .gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist); + release_sock(sk); + rtnl_unlock(); +mc_msf_out: + kfree(p); + return err; + } } err = do_ipv6_setsockopt(sk, level, optname, optval, optlen); -- 2.7.4