From a6a5993243550b09f620941dea741b7421fdf79c Mon Sep 17 00:00:00 2001 From: Ding Tianhong Date: Sat, 29 Apr 2017 10:38:48 +0800 Subject: iov_iter: don't revert iov buffer if csum error 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. Fixes: 327868212381 ("make skb_copy_datagram_msg() et.al. preserve->msg_iter on error") Cc: stable@vger.kernel.org # v4.11 Signed-off-by: Ding Tianhong Acked-by: Al Viro Signed-off-by: Wei Yongjun Signed-off-by: Al Viro --- net/core/datagram.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'net/core') diff --git a/net/core/datagram.c b/net/core/datagram.c index f4947e737f34..d797baa69e43 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -760,7 +760,7 @@ 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 { @@ -768,15 +768,16 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, if (skb_copy_and_csum_datagram(skb, hlen, &msg->msg_iter, chunk, &csum)) goto fault; - if (csum_fold(csum)) - goto csum_error; + + if (csum_fold(csum)) { + iov_iter_revert(&msg->msg_iter, chunk); + return -EINVAL; + } + if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) netdev_rx_csum_fault(skb->dev); } return 0; -csum_error: - iov_iter_revert(&msg->msg_iter, chunk); - return -EINVAL; fault: return -EFAULT; } -- cgit v1.2.3