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 has_capability_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: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: stable@vger.kernel.org # v3.18 Fixes: upstream a082c6f680da ("ovl: filter trusted xattr for non-admin") Fixes: 3.18 4bcc9b4b3a0a ("ovl: filter trusted xattr for non-admin") --- Replaced ns_capable_noaudit with 3.18.y tree specific has_capability_noaudit present in original submission to kernel.org commit 5c2e9f346b815841f9bed6029ebcb06415caf640 ("ovl: filter of trusted xattr results in audit")
fs/overlayfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index a01ec1836a72..1175efa5e956 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -265,7 +265,8 @@ 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) && + has_capability_noaudit(current, CAP_SYS_ADMIN); }
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)