Patch "sparc64: ldc abort during vds iso boot" has been added to the 4.9-stable tree

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

sparc64: ldc abort during vds iso boot

to the 4.9-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:
sparc64-ldc-abort-during-vds-iso-boot.patch
and it can be found in the queue-4.9 subdirectory.

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

From: Jag Raman <[email protected]>
Date: Fri, 9 Jun 2017 12:29:31 -0400
Subject: sparc64: ldc abort during vds iso boot

From: Jag Raman <[email protected]>

[ Upstream commit 6c95483b768c62f8ee933ae08a1bdbcb78b5410f ]

Orabug: 20902628

When an ldc control-only packet is received during data exchange in read_nonraw(), a new rx head is calculated but the rx queue head is not actually advanced (rx_set_head() is not called) and a branch is taken to 'no_data' at which point two things can happen depending on the value of the newly calculated rx head and the current rx tail:

- If the rx queue is determined to be not empty, then the wrong packet is picked up.

- If the rx queue is determined to be empty, then a read error (EAGAIN) is eventually returned since it is falsely assumed that more data was expected.

The fix is to update the rx head and return in case of a control only packet during data exchange.

---
 arch/sparc/kernel/ldc.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

@@ -1733,9 +1733,14 @@ static int read_nonraw(struct ldc_channe
 
 		lp->rcv_nxt = p->seqid;
 
+		/*
+		 * If this is a control-only packet, there is nothing
+		 * else to do but advance the rx queue since the packet
+		 * was already processed above.
+		 */
 		if (!(p->type & LDC_DATA)) {
 			new = rx_advance(lp, new);
-			goto no_data;
+			break;
 		}
 		if (p->stype & (LDC_ACK | LDC_NACK)) {
 			err = data_ack_nack(lp, p);

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

queue-4.9/sparc64-ldc-abort-during-vds-iso-boot.patch