From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.216.245.30 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792763924; b=PsBwRZIMnjZr2yW7ru2qiDfToTzl1tlgWLu3e5CMDBlaUhSgOjySeHB/veBJBf04kz4y /MG08qr2AKE4zom0Vs1TvwjN0pI2fJh3igcFm/Dm64RGXveu42utzPNOdtGvN8J7KuWH0 iCrPvNW9CeQ7K+EKzo/+Qg8GnRzMflg0oqpjCdL8aBZhxlKPbMqaEfwBWOekOxrWdhKA5 hRgB1hXisKfnQLcrCFl+m4j0QP2k7nFyEiNy66lv2MYhJzM5iC7LcWQhoF8JA7jhELuNo JcqQJBOz2Ji6NgnatzgjmQUJwuTEIr4uSo5a++kIYcQePYBncZyW6jE2Wd2NiYYyV3Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792763924; h=DMARC-Filter:Received:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=YPxBi3Vqxd3Ic6ZcIhyuXJVsyxzhS7zl20HxoI3pRO8=; b=nMDPIkLZ/tI3wkJ6gAMSXkXqxWZZPoRTj9wBGwVGL/41bJUViSsq/Of7Uc8gCd8Fgqmt UQUYxSnYrbms38h5TCiRoto30Xrbn9GSsvj7sGtsRZHuQcqbVAEoK4kRrT0EZh3xNVNOn JuUZDoEuJfOE8q0WA5lc3Ucqvfk5PsNqDMOgkBEKAGiMZxFoom3tgdqhC+ecHG6rolAaS 1sWgnKk24I0QRYKkYRZl2uA5iBSWHV9tLxuvT0ob3j2CR8icJ0BGotYgwohrYdL1xsMSO 2T9s0L6LUqh/GF8PT8dNnv7vmEveKmqfA+mViwImhZ8CCl/WSTJrxO9Sg6HOezVNxEQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=strlen.de; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc; arc=none smtp.remote-ip=91.216.245.30 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31650606A31A for ; Fri, 23 Oct 2026 13:58:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 31650606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id 9B1C960796; Fri, 23 Oct 2026 15:58:42 +0200 (CEST) From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH libnftnl 6/7] src: utils: keep old name if strndup fails Date: Fri, 23 Oct 2026 15:58:05 +0200 Message-ID: <20261023135806.7259-7-fw@strlen.de> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261023135806.7259-1-fw@strlen.de> References: <20261023135806.7259-1-fw@strlen.de> X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit LLM finding: flag/pointer state inconsistency on allocation failure. In practice, strndup should never fail for any realistic scenario, however, its clearly a bug. Free old value after allocation succeded, not before. nftnl_parse_str_attr has the same issue, delegate to the fixed function instead of open-coding. Signed-off-by: Florian Westphal --- src/utils.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/src/utils.c b/src/utils.c index bbe44b4d532d..ec15f9bc8646 100644 --- a/src/utils.c +++ b/src/utils.c @@ -139,13 +139,15 @@ void __noreturn __abi_breakage(const char *file, int line, const char *reason) int nftnl_set_str_attr(const char **dptr, uint32_t *flags, uint16_t attr, const void *data, uint32_t data_len) { - if (*flags & (1 << attr)) - xfree(*dptr); + char *new = strndup(data, data_len); - *dptr = strndup(data, data_len); - if (!*dptr) + if (!new) return -1; + if (*flags & (1 << attr)) + xfree(*dptr); + + *dptr = new; *flags |= (1 << attr); return 0; } @@ -196,14 +198,14 @@ char *nftnl_attr_get_ifname(const struct nlattr *attr) int nftnl_parse_str_attr(const struct nlattr *tb, int attr, const char **field, uint32_t *flags) { + const char *s; + uint32_t len; + if (!tb) return 0; - if (*flags & (1 << attr)) - xfree(*field); - *field = strdup(mnl_attr_get_str(tb)); - if (!*field) - return -1; - *flags |= (1 << attr); - return 0; + len = mnl_attr_get_payload_len(tb); + s = mnl_attr_get_str(tb); + + return nftnl_set_str_attr(field, flags, attr, s, len); } -- 2.55.0