netfilter: nf_conntrack_ftp: Fix debug output

[ Upstream commit 3a069024d371125227de3ac8fa74223fcf473520 ]

The find_pattern() debug output was printing the 'skip' character.
This can be a NULL-byte and messes up further pr_debug() output.

Output without the fix:
kernel: nf_conntrack_ftp: Pattern matches!
kernel: nf_conntrack_ftp: Skipped up to `<7>nf_conntrack_ftp: find_pattern `PORT': dlen = 8
kernel: nf_conntrack_ftp: find_pattern `EPRT': dlen = 8

Output with the fix:
kernel: nf_conntrack_ftp: Pattern matches!
kernel: nf_conntrack_ftp: Skipped up to 0x0 delimiter!
kernel: nf_conntrack_ftp: Match succeeded!
kernel: nf_conntrack_ftp: conntrack_ftp: match `172,17,0,100,200,207' (20 bytes at 4150681645)
kernel: nf_conntrack_ftp: find_pattern `PORT': dlen = 8

Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index a11c304..efc14c7 100644 (file)
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -323,7 +323,7 @@ static int find_pattern(const char *data, size_t dlen,
                i++;
        }
 
-       pr_debug("Skipped up to `%c'!\n", skip);
+       pr_debug("Skipped up to 0x%hhx delimiter!\n", skip);
 
        *numoff = i;
        *numlen = getnum(data + i, dlen - i, cmd, term, numoff);