Subject: Re: linux-next: block/drbd tree build warning

From: Lars Ellenberg <[email-masked]>
Date: Tue, 6 Oct 2009 09:17:00 +0200

On Tue, Oct 06, 2009 at 02:01:54PM +1100, Stephen Rothwell wrote:
> Hi Jens, Philipp,
> 
> Today's linux-next build (x86_64 allmodconfig) produced this warning:
> 
> drivers/block/drbd/drbd_nl.c: In function 'drbd_nl_init':
> drivers/block/drbd/drbd_nl.c:2309: warning: passing argument 3 of 'cn_add_callback' from incompatible pointer type
> include/linux/connector.h:167: note: expected 'void (*)(struct cn_msg *, struct netlink_skb_parms *)' but argument is of type 'void (*)(struct cn_msg *)'

Thanks, expected after our connector related patches got in.

-- 
Author: Philipp Reisner <[email-masked]>
Date:   Tue Sep 29 13:35:30 2009 +0200

drbd: Work on permission enforcement

Now we have the capabilities of the sending process available,
use them to enforce CAP_SYS_ADMIN.

Signed-off-by: Philipp Reisner <[email-masked]>

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 1927ace..00ce3a4 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -2002,7 +2002,7 @@ static struct cn_handler_struct cnd_table[] = {
 	[ P_new_c_uuid ]	= { &drbd_nl_new_c_uuid,	0 },
 };
 
-static void drbd_connector_callback(struct cn_msg *req)
+static void drbd_connector_callback(struct cn_msg *req, struct netlink_skb_parms *nsp)
 {
 	struct drbd_nl_cfg_req *nlp = (struct drbd_nl_cfg_req *)req->data;
 	struct cn_handler_struct *cm;
@@ -2019,6 +2019,11 @@ static void drbd_connector_callback(struct cn_msg *req)
 		return;
 	}
 
+	if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN)) {
+		retcode = ERR_PERM;
+		goto fail;
+	}
+
 	mdev = ensure_mdev(nlp);
 	if (!mdev) {
 		retcode = ERR_MINOR_INVALID;
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 69dc711..233db5c 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -138,6 +138,7 @@ enum drbd_ret_codes {
 	ERR_VERIFY_RUNNING	= 149, /* DRBD 8.2 only */
 	ERR_DATA_NOT_CURRENT	= 150,
 	ERR_CONNECTED		= 151, /* DRBD 8.3 only */
+	ERR_PERM		= 152,
 
 	/* insert new ones above this line */
 	AFTER_LAST_ERR_CODE