Patch "RDS-TCP: Recover correctly from pskb_pull()/pksb_trim() failure in rds_tcp_data_recv" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

RDS-TCP: Recover correctly from pskb_pull()/pksb_trim() failure in rds_tcp_data_recv

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
rds-tcp-recover-correctly-from-pskb_pull-pksb_trim-failure-in-rds_tcp_data_recv.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Sowmini Varadhan <[email protected]>
Date: Mon, 26 Oct 2015 12:46:37 -0400
Subject: RDS-TCP: Recover correctly from pskb_pull()/pksb_trim() failure in rds_tcp_data_recv

From: Sowmini Varadhan <[email protected]>

[ Upstream commit 8ce675ff39b9958d1c10f86cf58e357efaafc856 ]

Either of pskb_pull() or pskb_trim() may fail under low memory conditions. If rds_tcp_data_recv() ignores such failures, the application will receive corrupted data because the skb has not been correctly carved to the RDS datagram size.

Avoid this by handling pskb_pull/pskb_trim failure in the same manner as the skb_clone failure: bail out of rds_tcp_data_recv(), and retry via the deferred call to rds_send_worker() that gets set up on ENOMEM from rds_tcp_read_sock()

---
 net/rds/tcp_recv.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

@@ -214,8 +214,15 @@ static int rds_tcp_data_recv(read_descri
 			}
 
 			to_copy = min(tc->t_tinc_data_rem, left);
-			pskb_pull(clone, offset);
-			pskb_trim(clone, to_copy);
+			if (!pskb_pull(clone, offset) ||
+			    pskb_trim(clone, to_copy)) {
+				pr_warn("rds_tcp_data_recv: pull/trim failed "
+					"left %zu data_rem %zu skb_len %d\n",
+					left, tc->t_tinc_data_rem, skb->len);
+				kfree_skb(clone);
+				desc->error = -ENOMEM;
+				goto out;
+			}
 			skb_queue_tail(&tinc->ti_skb_list, clone);
 
 			rdsdebug("skb %p data %p len %d off %u to_copy %zu -> "

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/rds-tcp-recover-correctly-from-pskb_pull-pksb_trim-failure-in-rds_tcp_data_recv.patch