call_ad() computes the netlink error payload size with min(SIZE_MAX, sizeof(*errmsg) + nlmsg_len(nlh)), but min(SIZE_MAX, x) is always x, so the guard is a no-op. Replace it with an explicit negative-length check and check_add_overflow() so the addition is validated before being passed to nlmsg_new(). Signed-off-by: David Baum --- net/netfilter/ipset/ip_set_core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index a2fe711cb5e3..11d3854d9b11 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -1763,13 +1764,18 @@ call_ad(struct net *net, struct sock *ctnl, struct sk_buff *skb, struct nlmsghdr *rep, *nlh = nlmsg_hdr(skb); struct sk_buff *skb2; struct nlmsgerr *errmsg; - size_t payload = min(SIZE_MAX, - sizeof(*errmsg) + nlmsg_len(nlh)); + int nlmsg_payload_len = nlmsg_len(nlh); + size_t payload; int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); struct nlattr *cda[IPSET_ATTR_CMD_MAX + 1]; struct nlattr *cmdattr; u32 *errline; + if (nlmsg_payload_len < 0 || + check_add_overflow(sizeof(*errmsg), + (size_t)nlmsg_payload_len, &payload)) + return -ENOMEM; + skb2 = nlmsg_new(payload, GFP_KERNEL); if (!skb2) return -ENOMEM; -- 2.50.1 (Apple Git-155)