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| author |   Andy Lutomirski <luto@amacapital.net> | 2014-10-08 12:32:47 -0700 |
|---|---|---|
| committer | Andy Lutomirski <luto@amacapital.net> | 2014-10-08 12:32:47 -0700 |
| commit | a1480dcc3c706e309a88884723446f2e84fedd5b (patch) | |
| tree | fa2a425b8607586c11127ea35344d893e6a4a4f0 /fs/namespace.c | |
| parent | Linux 3.17 (diff) | |
| download | linux-dev-a1480dcc3c706e309a88884723446f2e84fedd5b.tar.xz linux-dev-a1480dcc3c706e309a88884723446f2e84fedd5b.zip | |
fs: Add a missing permission check to do_umount
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>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index ef42d9bee212..7f67b463a5b4 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1356,6 +1356,8 @@ 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); |