From 8691a9a3382f17fbf1ed808c956672c70369a2e0 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sat, 16 Nov 2013 22:16:47 +0100 Subject: [PATCH] netfilter: nft_compat: fix error path in nft_parse_compat() The patch 0ca743a55991: "netfilter: nf_tables: add compatibility layer for x_tables", leads to the following Smatch warning: "net/netfilter/nft_compat.c:140 nft_parse_compat() warn: signedness bug returning '(-34)'" This nft_parse_compat function returns error codes but the return type is u8 so the error codes are transformed into small positive values. The callers don't check the return. Reported-by: Dan Carpenter Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_compat.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c index a82667c64729..da0c1f4ada12 100644 --- a/net/netfilter/nft_compat.c +++ b/net/netfilter/nft_compat.c @@ -128,7 +128,7 @@ static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 }, }; -static u8 nft_parse_compat(const struct nlattr *attr, bool *inv) +static int nft_parse_compat(const struct nlattr *attr, u8 *proto, bool *inv) { struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; u32 flags; @@ -148,7 +148,8 @@ static u8 nft_parse_compat(const struct nlattr *attr, bool *inv) if (flags & NFT_RULE_COMPAT_F_INV) *inv = true; - return ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); + *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); + return 0; } static int @@ -166,8 +167,11 @@ nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr, target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info); - if (ctx->nla[NFTA_RULE_COMPAT]) - proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv); + if (ctx->nla[NFTA_RULE_COMPAT]) { + ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); + if (ret < 0) + goto err; + } nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv); @@ -356,8 +360,11 @@ nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info); - if (ctx->nla[NFTA_RULE_COMPAT]) - proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv); + if (ctx->nla[NFTA_RULE_COMPAT]) { + ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); + if (ret < 0) + goto err; + } nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv); -- 2.11.0