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authorAndy Lutomirski <luto@amacapital.net>2014-10-08 12:32:47 -0700
committerJiri Slaby <jslaby@suse.cz>2014-10-17 09:43:21 +0200
commit8d9c8c3980a85d79db13c5ce4bb118fef32d4f50 (patch)
tree3a6e2d463b2d344617be486d0c238b1cd006c9e1 /fs
parentae74a22cb5024a22753c3bb5c7d4036db1929fc0 (diff)
fs: Add a missing permission check to do_umount
commit a1480dcc3c706e309a88884723446f2e84fedd5b upstream. Accessing do_remount_sb should require global CAP_SYS_ADMIN, but only one of the two call sites was appropriately protected. Fixes CVE-2014-7975. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'fs')
-rw-r--r--fs/namespace.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 4ea2b7378d8c..4b14bfc4cfce 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1277,6 +1277,8 @@ static int do_umount(struct mount *mnt, int flags)
* Special case for "unmounting" root ...
* we just try to remount it readonly.
*/
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
down_write(&sb->s_umount);
if (!(sb->s_flags & MS_RDONLY))
retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);