From: Thomas Jarosch <thomas.jarosch@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- net/netfilter/nf_conntrack_ftp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c index 0ecb3e289ef2..8d96738b7dfd 100644 --- a/net/netfilter/nf_conntrack_ftp.c +++ b/net/netfilter/nf_conntrack_ftp.c @@ -322,7 +322,7 @@ 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); -- 2.11.0