laforge has submitted this change and it was merged. (
https://gerrit.osmocom.org/c/osmo-msc/+/13470 )
Change subject: libmsc/db.c: fix potential integer overflow
..
libmsc/db.c: fix potential integer overflow
The value of 'sms->user_data_len' is fetched from the database:
sms->user_data_len = dbi_result_get_field_length(result, "user_data");
and this is where the problem is. As per the libdbi's documentation
(see 3.5.3), dbi_result_get_field_length() returns the length in
bytes of the value stored in the specified field:
unsigned int dbi_result_get_field_length(dbi_result Result,
const char *fieldname)
so 'unsigned int' is assigned to 'uint8_t', what could lead to an
integer overflow if the value is grather than 0xff. As a result,
if the database for some reason does contain such odd TP-UD,
the truncation of 'user_data' would be done incorrectly.
Let's avoid such direct assignment, and use a separate variable.
Also, let's warn user if TP-UDL value is grether than 140, as
per 3GPP TS 03.40.
Change-Id: Ibbd588545e1a4817504c806a3d02cf59d5938ee2
Related: OS#3684
---
M src/libmsc/db.c
1 file changed, 27 insertions(+), 9 deletions(-)
Approvals:
laforge: Looks good to me, approved
Jenkins Builder: Verified
diff --git a/src/libmsc/db.c b/src/libmsc/db.c
index e3995a6..1fe8e6b 100644
--- a/src/libmsc/db.c
+++ b/src/libmsc/db.c
@@ -236,6 +236,7 @@
long long unsigned int sender_id;
const char *text, *daddr;
const unsigned char *user_data;
+ unsigned int user_data_len;
char buf[32];
char *quoted;
dbi_result result2;
@@ -273,10 +274,15 @@
if (daddr)
OSMO_STRLCPY_ARRAY(sms->dst.addr, daddr);
- sms->user_data_len = dbi_result_get_field_length(result, "user_data");
+ user_data_len = dbi_result_get_field_length(result, "user_data");
user_data = dbi_result_get_binary(result, "user_data");
- if (sms->user_data_len > sizeof(sms->user_data))
- sms->user_data_len = (uint8_t) sizeof(sms->user_data);
+ if (user_data_len > sizeof(sms->user_data)) {
+ LOGP(DDB, LOGL_ERROR,
+"SMS TP-UD length %u is too big, truncating to %zu\n",
+user_data_len, sizeof(sms->user_data));
+ user_data_len = (uint8_t) sizeof(sms->user_data);
+ }
+ sms->user_data_len = user_data_len;
memcpy(sms->user_data, user_data, sms->user_data_len);
text = dbi_result_get_string(result, "text");
@@ -395,6 +401,7 @@
{
struct gsm_sms *sms = sms_alloc();
const unsigned char *user_data;
+ unsigned int user_data_len;
const char *text, *addr;
if (!sms)
@@ -419,10 +426,15 @@
sms->dst.ton = dbi_result_get_ulonglong(result, "dest_ton");
sms->dst.npi = dbi_result_get_ulonglong(result, "dest_npi");
- sms->user_data_len = dbi_result_get_field_length(result, "user_data");
+ user_data_len = dbi_result_get_field_length(result, "user_data");
user_data = dbi_result_get_binary(result, "user_data");
- if (sms->user_data_len > sizeof(sms->user_data))
- sms->user_data_len = (uint8_t) sizeof(sms->user_data);
+ if (user_data_len > sizeof(sms->user_data)) {
+ LOGP(DDB, LOGL_ERROR,
+"SMS TP-UD length %u is too big, truncating to %zu\n",
+user_data_len, sizeof(sms->user_data));
+ user_data_len = (uint8_t) sizeof(sms->user_data);
+ }
+ sms->user_data_len = user_data_len;
memcpy(sms->user_data, user_data, sms->user_data_len);
text = dbi_result_get_string(result, "text");
@@ -753,6 +765,7 @@
struct gsm_sms *sms = sms_alloc();
const char *text, *daddr, *saddr;
const unsigned char *user_data;
+ unsigned int user_data_len;
time_t validity_timestamp;
if (!sms)
@@ -789,10 +802,15 @@
if (saddr)
OSMO_STRLCPY_ARRAY(sms->src.addr, saddr);
- sms->user_data_len = dbi_result_get_field_length(result, "user_data");
+ user_data_len = dbi_result_get_field_length(result, "user_data");
user_data = dbi_result_get_binary(result, "user_data");
- if (sms->user_data_len > sizeof(sms->user_data))
- sms->user_data_len = (uint8_t) sizeof(sms->user_data);
+ if (user_data_len > sizeof(sms->user_data)) {
+ LOGP(DDB, LOGL_ERROR,
+"SMS TP-UD length %u is too big, truncating to %zu\n",
+user_data_len, sizeof(sms->user_data));
+ user_data_len = (uint8_t) sizeof(sms->user_data);
+ }
+ sms->user_data_len = user_data_len;
if (user_data)
memcpy(sms->user_data, user_data, sms->user_data_len);
--
To view, visit https://gerrit.osmocom.org/c/osmo-msc/+/13470
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