[v3] iov_iter: don't revert iov buffer if csum error

Message ID 12d4d81f-40c7-c83d-11d6-290acc084695@huawei.com
State New
Headers show

Commit Message

Ding Tianhong May 3, 2017, 7:02 a.m.
The patch 327868212381 (make skb_copy_datagram_msg() et.al. preserve
->msg_iter on error) will revert the iov buffer if copy to iter
failed, but it didn't copy any datagram if the skb_checksum_complete
error, so no need to revert any data at this place.

v2: Sabrina notice that return -EFAULT when checksum error is not correct
    here, it would confuse the caller about the return value, so fix it.

v3: According AI's suggestion, directly return -EINVAL when __skb_checksum_complete()
    return error is a more simple solution.

Fixes: 327868212381 ("make skb_copy_datagram_msg() et.al. preserve->msg_iter on error")
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

---
 net/core/datagram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
1.8.3.1

Comments

Al Viro May 3, 2017, 7:07 a.m. | #1
On Wed, May 03, 2017 at 03:02:32PM +0800, Ding Tianhong wrote:
> The patch 327868212381 (make skb_copy_datagram_msg() et.al. preserve

> ->msg_iter on error) will revert the iov buffer if copy to iter

> failed, but it didn't copy any datagram if the skb_checksum_complete

> error, so no need to revert any data at this place.


See a6a5993243550b09f620941dea741b7421fdf79c in mainline...
Ding Tianhong May 3, 2017, 7:15 a.m. | #2
Miss it, it is already in the kernel tree, sorry for the noisy.

On 2017/5/3 15:02, Ding Tianhong wrote:
> The patch 327868212381 (make skb_copy_datagram_msg() et.al. preserve

> ->msg_iter on error) will revert the iov buffer if copy to iter

> failed, but it didn't copy any datagram if the skb_checksum_complete

> error, so no need to revert any data at this place.

> 

> v2: Sabrina notice that return -EFAULT when checksum error is not correct

>     here, it would confuse the caller about the return value, so fix it.

> 

> v3: According AI's suggestion, directly return -EINVAL when __skb_checksum_complete()

>     return error is a more simple solution.

> 

> Fixes: 327868212381 ("make skb_copy_datagram_msg() et.al. preserve->msg_iter on error")

> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>

> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

> ---

>  net/core/datagram.c | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/net/core/datagram.c b/net/core/datagram.c

> index 0306543..726bf8a 100644

> --- a/net/core/datagram.c

> +++ b/net/core/datagram.c

> @@ -719,7 +719,7 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb,

> 

>  	if (msg_data_left(msg) < chunk) {

>  		if (__skb_checksum_complete(skb))

> -			goto csum_error;

> +			return -EINVAL;

>  		if (skb_copy_datagram_msg(skb, hlen, msg, chunk))

>  			goto fault;

>  	} else {

>

Patch hide | download patch | download mbox

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 0306543..726bf8a 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -719,7 +719,7 @@  int skb_copy_and_csum_datagram_msg(struct sk_buff *skb,

 	if (msg_data_left(msg) < chunk) {
 		if (__skb_checksum_complete(skb))
-			goto csum_error;
+			return -EINVAL;
 		if (skb_copy_datagram_msg(skb, hlen, msg, chunk))
 			goto fault;
 	} else {