2021-11-04 04:20:17

by Wu Bo

Subject: [PATCH RESEND] nbd: code clean for nbd_genl_status()

A simple code clean for nbd_genl_status()

Signed-off-by: Wu Bo <[email protected]>
---
drivers/block/nbd.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b47b2a8..175ea97 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -2375,7 +2375,6 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
reply_head = genlmsg_put_reply(reply, info, &nbd_genl_family, 0,
NBD_CMD_STATUS);
if (!reply_head) {
- nlmsg_free(reply);
goto out;
}

@@ -2383,7 +2382,6 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
if (index == -1) {
ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
if (ret) {
- nlmsg_free(reply);
goto out;
}
} else {
@@ -2392,7 +2390,6 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
if (nbd) {
ret = populate_nbd_status(nbd, reply);
if (ret) {
- nlmsg_free(reply);
goto out;
}
}
@@ -2401,6 +2398,8 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
genlmsg_end(reply, reply_head);
ret = genlmsg_reply(reply, info);
out:
+ if (reply)
+ nlmsg_free(reply);
mutex_unlock(&nbd_index_mutex);
return ret;
}
--
1.8.3.1

2021-11-04 08:49:53

by Christoph Hellwig

Subject: Re: [PATCH RESEND] nbd: code clean for nbd_genl_status()

On Thu, Nov 04, 2021 at 12:38:23PM +0800, Wu Bo wrote:
> if (!reply_head) {
> - nlmsg_free(reply);
> goto out;
> }

Please also drop the now pointless braces.

> out:
> + if (reply)
> + nlmsg_free(reply);

Please just use a different label for just unlocking vs also freeing
the reply.

2021-11-05 03:07:24

by Wu Bo

Subject: Re: [PATCH RESEND] nbd: code clean for nbd_genl_status()

On 2021/11/4 16:48, Christoph Hellwig wrote:
> On Thu, Nov 04, 2021 at 12:38:23PM +0800, Wu Bo wrote:
>> if (!reply_head) {
>> - nlmsg_free(reply);
>> goto out;
>> }
>
> Please also drop the now pointless braces.
>
ok. Will do in v2.
>> out:
>> + if (reply)
>> + nlmsg_free(reply);
>
> Please just use a different label for just unlocking vs also freeing
> the reply.
> .
ok. Will do in v2.

Thanks.

Wu Bo

2021-11-05 11:42:39

by Josef Bacik

Subject: Re: [PATCH RESEND] nbd: code clean for nbd_genl_status()

On Thu, Nov 04, 2021 at 12:38:23PM +0800, Wu Bo wrote:
> A simple code clean for nbd_genl_status()
>
> Signed-off-by: Wu Bo <[email protected]>

This isn't ok, genlmsg_reply() free's the reply, this introduces a double free.
Thanks,

Josef