2022-04-01 12:29:48

by Ildar Kamaletdinov

[permalink] [raw]
Subject: [PATCH BlueZ 5/6] device: Limit width of fields in sscanf

In src/device.c few sscanf does not limit width of uuid field. This
could lead to static overflow and stack corruption.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
---
src/device.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/device.c b/src/device.c
index 381faf91c..8dc12d026 100644
--- a/src/device.c
+++ b/src/device.c
@@ -3790,8 +3790,8 @@ static int load_desc(char *handle, char *value,
return -EIO;

/* Check if there is any value stored, otherwise it is just the UUID */
- if (sscanf(value, "%04hx:%s", &val, uuid_str) != 2) {
- if (sscanf(value, "%s", uuid_str) != 1)
+ if (sscanf(value, "%04hx:%36s", &val, uuid_str) != 2) {
+ if (sscanf(value, "%36s", uuid_str) != 1)
return -EIO;
val = 0;
}
@@ -3840,9 +3840,9 @@ static int load_chrc(char *handle, char *value,
return -EIO;

/* Check if there is any value stored */
- if (sscanf(value, GATT_CHARAC_UUID_STR ":%04hx:%02hx:%32s:%s",
+ if (sscanf(value, GATT_CHARAC_UUID_STR ":%04hx:%02hx:%32s:%36s",
&value_handle, &properties, val_str, uuid_str) != 4) {
- if (sscanf(value, GATT_CHARAC_UUID_STR ":%04hx:%02hx:%s",
+ if (sscanf(value, GATT_CHARAC_UUID_STR ":%04hx:%02hx:%36s",
&value_handle, &properties, uuid_str) != 3)
return -EIO;
val_len = 0;
@@ -3884,8 +3884,8 @@ static int load_incl(struct gatt_db *db, char *handle, char *value,
if (sscanf(handle, "%04hx", &start) != 1)
return -EIO;

- if (sscanf(value, GATT_INCLUDE_UUID_STR ":%04hx:%04hx:%s", &start, &end,
- uuid_str) != 3)
+ if (sscanf(value, GATT_INCLUDE_UUID_STR ":%04hx:%04hx:%36s", &start,
+ &end, uuid_str) != 3)
return -EIO;

/* Log debug message. */
@@ -3918,7 +3918,7 @@ static int load_service(struct gatt_db *db, char *handle, char *value)
if (sscanf(handle, "%04hx", &start) != 1)
return -EIO;

- if (sscanf(value, "%[^:]:%04hx:%s", type, &end, uuid_str) != 3)
+ if (sscanf(value, "%[^:]:%04hx:%36s", type, &end, uuid_str) != 3)
return -EIO;

if (g_str_equal(type, GATT_PRIM_SVC_UUID_STR))
--
2.35.1