Patch "netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find()" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-nfnetlink_osf-fix-possible-bogus-match-in-.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 44dd8eab211aabe5145859c16e2fcbda68aa58d8
Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date:   Wed Sep 7 10:26:18 2022 +0200

    netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find()
    
    [ Upstream commit 559c36c5a8d730c49ef805a72b213d3bba155cc8 ]
    
    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@xxxxxxxxxxxxx>
    Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c
index 79fbf37291f3..51e3953b414c 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);