diff mbox series

[net,4/4] netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find()

Message ID 20220908095757.1755-5-fw@strlen.de
State Accepted
Delegated to: Pablo Neira
Headers show
Series [net,1/4] netfilter: nf_conntrack_sip: fix ct_sip_walk_headers | expand

Commit Message

Florian Westphal Sept. 8, 2022, 9:57 a.m. UTC 
From: Pablo Neira Ayuso <pablo@netfilter.org>

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>
---
 net/netfilter/nfnetlink_osf.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c
index 0fa2e2030427..ee6840bd5933 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);