netdev - [PATCH 2/2] netfilter: nft_bitwise: Adjust parentheses to fix memcmp size argument

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190814214347.4940-3-pablo@netfilter.org>
Date:   Wed, 14 Aug 2019 23:43:47 +0200
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     netfilter-devel@...r.kernel.org
Cc:     davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 2/2] netfilter: nft_bitwise: Adjust parentheses to fix memcmp size argument

From: Nathan Chancellor <natechancellor@...il.com>

clang warns:

net/netfilter/nft_bitwise.c:138:50: error: size argument in 'memcmp'
call is a comparison [-Werror,-Wmemsize-comparison]
        if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
                                      ~~~~~~~~~~~~~~~~~~^~
net/netfilter/nft_bitwise.c:138:6: note: did you mean to compare the
result of 'memcmp' instead?
        if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
            ^
                                                       )
net/netfilter/nft_bitwise.c:138:32: note: explicitly cast the argument
to size_t to silence this warning
        if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
                                      ^
                                      (size_t)(
1 error generated.

Adjust the parentheses so that the result of the sizeof is used for the
size argument in memcmp, rather than the result of the comparison (which
would always be true because sizeof is a non-zero number).

Fixes: bd8699e9e292 ("netfilter: nft_bitwise: add offload support")
Link: https://github.com/ClangBuiltLinux/linux/issues/638
Reported-by: kbuild test robot <lkp@...el.com>
Signed-off-by: Nathan Chancellor <natechancellor@...il.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@...gle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nft_bitwise.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c
index 1f04ed5c518c..974300178fa9 100644
--- a/net/netfilter/nft_bitwise.c
+++ b/net/netfilter/nft_bitwise.c
@@ -135,8 +135,8 @@ static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
 {
 	const struct nft_bitwise *priv = nft_expr_priv(expr);
 
-	if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
-	    priv->sreg != priv->dreg))
+	if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
+	    priv->sreg != priv->dreg)
 		return -EOPNOTSUPP;
 
 	memcpy(&ctx->regs[priv->dreg].mask, &priv->mask, sizeof(priv->mask));
-- 
2.11.0