libmisc: add check fopen return value in read_random_bytes()

Returns null when fopen fails. Then, using fread with a null pointer will cause a segfault.

Signed-off-by: Yan Zhu <zhuyan34@huawei.com>

diff --git a/libmisc/salt.c b/libmisc/salt.c
index f8ac566968d4d45aa8dac841c43112014a025e53..ebf162fc177a69c014c0ad11206993028e135e4a 100644 (file)
--- a/libmisc/salt.c
+++ b/libmisc/salt.c
@@ -175,6 +175,9 @@ static long read_random_bytes (void)
 
 #else
        FILE *f = fopen ("/dev/urandom", "r");
+       if (NULL == f) {
+               goto fail;
+       }
 
        if (fread (&randval, sizeof (randval), 1, f) != 1) {
                fclose(f);