The patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5c2e9f346b815841f9bed6029ebcb06415caf640 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
Date: Thu, 29 Aug 2019 11:30:14 -0700
Subject: [PATCH] ovl: filter of trusted xattr results in audit
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@xxxxxxxxxxx>
Cc: linux-security-module@xxxxxxxxxxxxxxx
Cc: kernel-team@xxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx # v3.18+
Fixes: a082c6f680da ("ovl: filter trusted xattr for non-admin")
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 7663aeb85fa3..bc14781886bf 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -383,7 +383,8 @@ 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)
