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 9c9d95f..3cee3a6 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -140,7 +140,7 @@
* 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" */