Fix for segfault when reading /proc/mdstat

Some kernel versions don't put a space between 'active' and '(auto-read-only)'
in /proc/mdstat.  This causes a parsing problem leaving 'level' set to
NULL which causes a crash.

So synthesise a space there if it is missing, and check for 'level' to
be NULL and don't de-ref if it is.

1 files changed, 1 insertions, 0 deletions

diff --git a/Monitor.c b/Monitor.c
index 6b0c760..54193f5 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -403,6 +403,7 @@ int Monitor(mddev_dev_t devlist,
 			struct mdstat_ent *mse;
 			for (mse=mdstat; mse; mse=mse->next)
 				if (mse->devnum != INT_MAX &&
+				    mse->level &&
 				    (strcmp(mse->level, "raid0")!=0 &&
 				     strcmp(mse->level, "linear")!=0)
 					) {