From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Wed, 7 Sep 2022 08:26:18 +0000 (+0200)
Subject: netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find()
X-Git-Tag: v6.1-rc5~417^2~54^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=559c36c5a8d730c49ef805a72b213d3bba155cc8;p=platform%2Fkernel%2Flinux-starfive.git

netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find()

nf_osf_find() incorrectly returns true on mismatch, this leads to
copying uninitialized memory area in nft_osf which can be used to leak
stale kernel stack data to userspace.

Fixes: 22c7652cdaa8 ("netfilter: nft_osf: Add version option support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
---

diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c
index 0fa2e20..ee6840b 100644
--- a/net/netfilter/nfnetlink_osf.c
+++ b/net/netfilter/nfnetlink_osf.c
@@ -269,6 +269,7 @@ bool nf_osf_find(const struct sk_buff *skb,
 	struct nf_osf_hdr_ctx ctx;
 	const struct tcphdr *tcp;
 	struct tcphdr _tcph;
+	bool found = false;
 
 	memset(&ctx, 0, sizeof(ctx));
 
@@ -283,10 +284,11 @@ bool nf_osf_find(const struct sk_buff *skb,
 
 		data->genre = f->genre;
 		data->version = f->version;
+		found = true;
 		break;
 	}
 
-	return true;
+	return found;
 }
 EXPORT_SYMBOL_GPL(nf_osf_find);