power: test_power: correctly handle empty writes
authorSasha Levin <sasha.levin@oracle.com>
Tue, 22 Dec 2015 17:43:36 +0000 (12:43 -0500)
committerSebastian Reichel <sre@kernel.org>
Thu, 7 Jan 2016 17:39:34 +0000 (18:39 +0100)
Writing 0 length data into test_power makes it access an invalid array
location and kill the system.

Fixes: f17ef9b2d ("power: Make test_power driver more dynamic.")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
drivers/power/test_power.c

index 83c42ea88f2b252b0c77a65cfe1bab12135e9dca..57246cdbd04263d24716c82ed189a42a38716daf 100644 (file)
@@ -301,6 +301,8 @@ static int map_get_value(struct battery_property_map *map, const char *key,
        buf[MAX_KEYLENGTH-1] = '\0';
 
        cr = strnlen(buf, MAX_KEYLENGTH) - 1;
+       if (cr < 0)
+               return def_val;
        if (buf[cr] == '\n')
                buf[cr] = '\0';