Patch "goldfish: Sanitize the broken interrupt handler" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    goldfish: Sanitize the broken interrupt handler

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:
     goldfish-sanitize-the-broken-interrupt-handler.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 <stable@vger.kernel.org> know about it.


>From 6cf18e6927c0b224f972e3042fb85770d63cb9f8 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 15 Feb 2017 11:11:51 +0100
Subject: goldfish: Sanitize the broken interrupt handler

From: Thomas Gleixner <tglx@linutronix.de>

commit 6cf18e6927c0b224f972e3042fb85770d63cb9f8 upstream.

This interrupt handler is broken in several ways:

  - It loops forever when the op code is not decodeable

  - It never returns IRQ_HANDLED because the only way to exit the loop
    returns IRQ_NONE unconditionally.

The whole concept of this is broken. Creating devices in an interrupt
handler is beyond any point of sanity.

Make it at least behave halfways sane so accidental users do not have to
deal with a hard to debug lockup.

Fixes: e809c22b8fb028 ("goldfish: add the goldfish virtual bus")
Reported-by: Gabriel C <nix.or.die@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/platform/goldfish/pdev_bus.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/drivers/platform/goldfish/pdev_bus.c
+++ b/drivers/platform/goldfish/pdev_bus.c
@@ -157,23 +157,26 @@ static int goldfish_new_pdev(void)
 static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id)
 {
 	irqreturn_t ret = IRQ_NONE;
+
 	while (1) {
 		u32 op = readl(pdev_bus_base + PDEV_BUS_OP);
-		switch (op) {
-		case PDEV_BUS_OP_DONE:
-			return IRQ_NONE;
 
+		switch (op) {
 		case PDEV_BUS_OP_REMOVE_DEV:
 			goldfish_pdev_remove();
+			ret = IRQ_HANDLED;
 			break;
 
 		case PDEV_BUS_OP_ADD_DEV:
 			goldfish_new_pdev();
+			ret = IRQ_HANDLED;
 			break;
+
+		case PDEV_BUS_OP_DONE:
+		default:
+			return ret;
 		}
-		ret = IRQ_HANDLED;
 	}
-	return ret;
 }
 
 static int goldfish_pdev_bus_probe(struct platform_device *pdev)


Patches currently in stable-queue which might be from tglx@linutronix.de are

queue-4.9/x86-platform-goldfish-prevent-unconditional-loading.patch
queue-4.9/goldfish-sanitize-the-broken-interrupt-handler.patch