From: Mark Salyzyn salyzyn@android.com
commit 5c2e9f346b815841f9bed6029ebcb06415caf640 upstream.
When filtering xattr list for reading, presence of trusted xattr results in a security audit log. However, if there is other content no errno will be set, and if there isn't, the errno will be -ENODATA and not -EPERM as is usually associated with a lack of capability. The check does not block the request to list the xattrs present.
Switch to ns_capable_noaudit to reflect a more appropriate check.
Signed-off-by: Mark Salyzyn salyzyn@android.com Cc: linux-security-module@vger.kernel.org Cc: kernel-team@android.com Cc: stable@vger.kernel.org # v3.18+ Fixes: a082c6f680da ("ovl: filter trusted xattr for non-admin") Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/overlayfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -386,7 +386,8 @@ static bool ovl_can_list(const char *s) return true;
/* Never list trusted.overlay, list other trusted for superuser only */ - return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN); + return !ovl_is_private_xattr(s) && + ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN); }
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)