[PATCH] md: require CAP_SYS_ADMIN for (re-)configuring md devices via sysfs

The ioctl requires CAP_SYS_ADMIN, so sysfs should too.  Note that we don't
require CAP_SYS_ADMIN for reading attributes even though the ioctl does.
There is no reason to limit the read access, and much of the information is
already available via /proc/mdstat

Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index c0da5eedc245..a5286beddcf5 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1926,6 +1926,8 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr,
 
         if (!entry->store)
                 return -EIO;
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
         return entry->store(rdev, page, length);
 }
 
@@ -2859,6 +2861,8 @@ md_attr_store(struct kobject *kobj, struct attribute *attr,
 
         if (!entry->store)
                 return -EIO;
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
         rv = mddev_lock(mddev);
         if (!rv) {
                 rv = entry->store(mddev, page, length);