netdev - [PATCH net-next 2/2] bpf_exp: free duplicated labels at exit time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1387190701-1893-3-git-send-email-dborkman@redhat.com>
Date:	Mon, 16 Dec 2013 11:45:01 +0100
From:	Daniel Borkmann <dborkman@...hat.com>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org
Subject: [PATCH net-next 2/2] bpf_exp: free duplicated labels at exit time

Valgrind found that extracted labels that are passed from the lexer
weren't freed upon exit. Therefore, add a small helper function that
walks label tables and frees them. Since also NULL can be passed to
free(3), we do not need to take care of that here. While at it, fix
up a spacing error in bpf_set_curr_label().

Signed-off-by: Daniel Borkmann <dborkman@...hat.com>
---
 tools/net/bpf_exp.y | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/tools/net/bpf_exp.y b/tools/net/bpf_exp.y
index f524110..d15efc9 100644
--- a/tools/net/bpf_exp.y
+++ b/tools/net/bpf_exp.y
@@ -40,8 +40,8 @@ extern void yyerror(const char *str);
 
 extern void bpf_asm_compile(FILE *fp, bool cstyle);
 static void bpf_set_curr_instr(uint16_t op, uint8_t jt, uint8_t jf, uint32_t k);
-static void bpf_set_curr_label(const char *label);
-static void bpf_set_jmp_label(const char *label, enum jmp_type type);
+static void bpf_set_curr_label(char *label);
+static void bpf_set_jmp_label(char *label, enum jmp_type type);
 
 %}
 
@@ -573,7 +573,7 @@ txa
 
 static int curr_instr = 0;
 static struct sock_filter out[BPF_MAXINSNS];
-static const char **labels, **labels_jt, **labels_jf, **labels_k;
+static char **labels, **labels_jt, **labels_jf, **labels_k;
 
 static void bpf_assert_max(void)
 {
@@ -594,13 +594,13 @@ static void bpf_set_curr_instr(uint16_t code, uint8_t jt, uint8_t jf,
 	curr_instr++;
 }
 
-static void bpf_set_curr_label(const char *label)
+static void bpf_set_curr_label(char *label)
 {
 	bpf_assert_max();
-        labels[curr_instr] = label;
+	labels[curr_instr] = label;
 }
 
-static void bpf_set_jmp_label(const char *label, enum jmp_type type)
+static void bpf_set_jmp_label(char *label, enum jmp_type type)
 {
 	bpf_assert_max();
 	switch (type) {
@@ -717,12 +717,25 @@ static void bpf_init(void)
 	assert(labels_k);
 }
 
+static void bpf_destroy_labels(void)
+{
+	int i;
+
+	for (i = 0; i < curr_instr; i++) {
+		free(labels_jf[i]);
+		free(labels_jt[i]);
+		free(labels_k[i]);
+		free(labels[i]);
+	}
+}
+
 static void bpf_destroy(void)
 {
-	free(labels);
+	bpf_destroy_labels();
 	free(labels_jt);
 	free(labels_jf);
 	free(labels_k);
+	free(labels);
 }
 
 void bpf_asm_compile(FILE *fp, bool cstyle)
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html