md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.
If we try to modify one of the md/ sysfs files
suspend_lo or suspend_hi
when the array is not active, we dereference a NULL.
Protect against that.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 09be637..2166af8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3573,7 +3573,8 @@
char *e;
unsigned long long new = simple_strtoull(buf, &e, 10);
- if (mddev->pers->quiesce == NULL)
+ if (mddev->pers == NULL ||
+ mddev->pers->quiesce == NULL)
return -EINVAL;
if (buf == e || (*e && *e != '\n'))
return -EINVAL;
@@ -3601,7 +3602,8 @@
char *e;
unsigned long long new = simple_strtoull(buf, &e, 10);
- if (mddev->pers->quiesce == NULL)
+ if (mddev->pers == NULL ||
+ mddev->pers->quiesce == NULL)
return -EINVAL;
if (buf == e || (*e && *e != '\n'))
return -EINVAL;