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=1793199446; b=Ft3PxUHqtxLXX6f/kvMduyYZgblN1UPwPRsUlfDQD09jopw0qqW7NOlLcbz0WlkQEya7 QDdLsoamMr/ZGAKkrpCCyScnBprk9BSdL5k0t0ef0uBh0eXozu3VVJqDQq9w+NHuZFoDo KY2rCP2IsJo21NdCB4xcNwFUvSVXbWbi0+WXQ/JQHpt13vSliB6fEcF9mWr1Kk5Efvov/ BHkjEvV3FFoqawuxA1g0sIgiiimhCXUPPuOFczIgO/FLlVrnpelQ9deyZuZcMb3BgGmLX lLYaWDfLYS46Wwp0BoVTbq400N3LJtULmMaNEy6hjng4WU4ERZJF4cQ39TxXevqAv5Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793199446; h=DMARC-Filter:Received:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=/+LhhO/3h9ac48SwxL2RtVMYqA41WzI+Egle+DK29rE=; b=ackOnR2VylnZv2XUswVAae0D9bpuBwwMNoOaJIlByXhT/wyaHLdp8b0ij8zA1dLfNuGn ZiBqjF6EkenXVhyv76Vlwb24T8iaF2/m9RSCaGNSPZaSWjG+VlI1dZrrO7Jj/gL6MzFuN jtU+Pq3ukBV0S3C/tPSXGGoqQavlTXC+nxXhevRaqkVKWmNYDW8Sa29yCI4mYbPW/1AiF lFaX2gX3IXa5sQrB7nn2V+yKq9UllS9jpwJyCkrkJmFkCJ+uy0pYPCPwv26pqEGy2F5dG QynfdEx1vwGskpX1pxxFsA0zUI4HeF9deakm2+yul+NhlD+ENTdLiAB5IanEVty4Rjg== 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 A81DB606A322 for ; Wed, 28 Oct 2026 14:57:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A81DB606A322 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 23855609D0; Wed, 28 Oct 2026 15:57:24 +0100 (CET) From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH libftnl 09/12] src: set: check for empty list explicitly Date: Wed, 28 Oct 2026 15:56:29 +0100 Message-ID: <20261028145632.7089-10-fw@strlen.de> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261028145632.7089-1-fw@strlen.de> References: <20261028145632.7089-1-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: When s->expr_list is empty the for-init assigns expr = container_of(&s->expr_list, nftnl_expr, head). Since `head` is at offset 0 in nftnl_expr, this yields expr == (nftnl_expr*)&s->expr_list: a pointer into the middle of the nftnl_set struct. The function returns this bogus pointer. Also set data_len to 0; normally users would use the _str getter which ignores the data_len anyway, but its better to initialise it to a known value. Signed-off-by: Florian Westphal --- src/set.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/src/set.c b/src/set.c index fc50f3f28055..f06223eaed86 100644 --- a/src/set.c +++ b/src/set.c @@ -253,8 +253,6 @@ EXPORT_SYMBOL(nftnl_set_get_data); const void *nftnl_set_get_data(const struct nftnl_set *s, uint16_t attr, uint32_t *data_len) { - struct nftnl_expr *expr; - if (!(s->flags & (1 << attr))) return NULL; @@ -313,9 +311,11 @@ const void *nftnl_set_get_data(const struct nftnl_set *s, uint16_t attr, case NFTNL_SET_USERDATA: return nftnl_mem_blob_get(&s->user_data, data_len); case NFTNL_SET_EXPR: - list_for_each_entry(expr, &s->expr_list, head) - break; - return expr; + *data_len = 0; + if (list_empty(&s->expr_list)) + return NULL; + + return list_entry(s->expr_list.next, struct nftnl_expr, head); } return NULL; } -- 2.55.0