5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodor Arsenij Larionov Trichkine [ Upstream commit d313499df66159b4b7971d760d16729598ab7e5a ] nft_nat_setup_netmap() builds the mapped address in an on-stack union nf_inet_addr. For an IPv4 mapping it writes only the 4-byte .ip member and the loop runs a single 32-bit iteration, but it then copies the whole 16-byte union into range->min_addr and range->max_addr, so the upper 12 bytes reach nf_nat_setup_info() uninitialised. KMSAN reports an uninit-value in nf_nat_setup_info() reached from nft_nat_eval(). The IPv6 path fills all 16 bytes and is not affected. Zero-initialise new_addr. Fixes: 3ff7ddb1353d ("netfilter: nft_nat: add netmap support") Signed-off-by: Theodor Arsenij Larionov Trichkine Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nft_nat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c index 2e1ee7d9d9c3c..2538f0c32f88c 100644 --- a/net/netfilter/nft_nat.c +++ b/net/netfilter/nft_nat.c @@ -64,8 +64,8 @@ static void nft_nat_setup_netmap(struct nf_nat_range2 *range, const struct nft_pktinfo *pkt, const struct nft_nat *priv) { + union nf_inet_addr new_addr = {}; struct sk_buff *skb = pkt->skb; - union nf_inet_addr new_addr; __be32 netmask; int i, len = 0; -- 2.53.0