mdev: fix a trivial SEGV

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 9c9d95f8a08c24ba192727e628a971e615f8994d..3cee3a66904ba71ee681c1fa7694e0d2dc1919b0 100644 (file)
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -140,7 +140,7 @@ static void make_device(char *path, int delete)
         * But since 2.6.25 block devices are also in /sys/class/block.
         * We use strstr("/block/") to forestall future surprises. */
        type = S_IFCHR;
-       if (strstr(path, "/block/") || strncmp(G.subsystem, "block", 5) == 0)
+       if (strstr(path, "/block/") || (G.subsystem && strncmp(G.subsystem, "block", 5) == 0))
                type = S_IFBLK;
 
        /* Make path point to "subsystem/device_name" */