[PATCH] openbsc[master]: libmsc: gsm340_gen_oa_sub() may return negative value

[Pablo Neira Ayuso]

Review at  https://gerrit.osmocom.org/3461

libmsc: gsm340_gen_oa_sub() may return negative value

gsm340_gen_oa() returns a negative value if the output buffer that the
caller passes is too small, so we have to check the return value of this
function.

Fixes: CID 174178
Fixes: CID 174179
Change-Id: I47215d7d89771730a7f84efa8aeeb187a0911fdb
---
M openbsc/src/libmsc/gsm_04_11.c
1 file changed, 9 insertions(+), 2 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/openbsc refs/changes/61/3461/1

diff --git a/openbsc/src/libmsc/gsm_04_11.c b/openbsc/src/libmsc/gsm_04_11.c
index 73e0f55..8b4ffce 100644
--- a/openbsc/src/libmsc/gsm_04_11.c
+++ b/openbsc/src/libmsc/gsm_04_11.c
@@ -213,9 +213,9 @@
 {
 	uint8_t *smsp;
 	uint8_t oa[12];	/* max len per 03.40 */
-	uint8_t oa_len = 0;
 	uint8_t octet_len;
 	unsigned int old_msg_len = msg->len;
+	int oa_len;
 
 	/* generate first octet with masked bits */
 	smsp = msgb_put(msg, 1);
@@ -233,6 +233,9 @@
 
 	/* generate originator address */
 	oa_len = gsm340_gen_oa_sub(oa, sizeof(oa), &sms->src);
+	if (oa_len < 0)
+		return -ENOSPC;
+
 	smsp = msgb_put(msg, oa_len);
 	memcpy(smsp, oa, oa_len);
 
@@ -282,9 +285,9 @@
 					     struct gsm_sms *sms)
 {
 	unsigned int old_msg_len = msg->len;
-	uint8_t oa_len = 0;
 	uint8_t oa[12];	/* max len per 03.40 */
 	uint8_t *smsp;
+	int oa_len;
 
 	/* generate first octet with masked bits */
 	smsp = msgb_put(msg, 1);
@@ -296,8 +299,12 @@
 	/* TP-MR (message reference) */
 	smsp = msgb_put(msg, 1);
 	*smsp = sms->msg_ref;
+
 	/* generate recipient address */
 	oa_len = gsm340_gen_oa_sub(oa, sizeof(oa), &sms->dst);
+	if (oa_len < 0)
+		return -ENOSPC;
+
 	smsp = msgb_put(msg, oa_len);
 	memcpy(smsp, oa, oa_len);
 

-- 
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I47215d7d89771730a7f84efa8aeeb187a0911fdb
Gerrit-PatchSet: 1
Gerrit-Project: openbsc
Gerrit-Branch: master
Gerrit-Owner: Pablo Neira Ayuso <pablo at gnumonks.org>