[CIFS] Can't rely on iov length and base when kernel_recvmsg returns error
When retrying kernel_recvmsg, reset iov_base and iov_len.
Note comment from Sridhar: "In the normal path, iov.iov_len is clearly set to 4. But i think you are
running into a case where kernel_recvmsg() is called via 'goto incomplete_rcv'
It happens if the previous call fails with EAGAIN.
If you want to call recvmsg() after EAGAIN failure, you need to reset iov."
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e9f9248..c682be8 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -417,9 +417,14 @@
msleep(1); /* minimum sleep to prevent looping
allowing socket to clear and app threads to set
tcpStatus CifsNeedReconnect if server hung */
- if (pdu_length < 4)
+ if (pdu_length < 4) {
+ iov.iov_base = (4 - pdu_length) +
+ (char *)smb_buffer;
+ iov.iov_len = pdu_length;
+ smb_msg.msg_control = NULL;
+ smb_msg.msg_controllen = 0;
goto incomplete_rcv;
- else
+ } else
continue;
} else if (length <= 0) {
if (server->tcpStatus == CifsNew) {