Patch "remoteproc: avoid stack overflow in debugfs file" has been added to the 4.3-stable tree

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

remoteproc: avoid stack overflow in debugfs file

to the 4.3-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:
remoteproc-avoid-stack-overflow-in-debugfs-file.patch
and it can be found in the queue-4.3 subdirectory.

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

From: Arnd Bergmann <[email protected]>
Date: Fri, 20 Nov 2015 18:26:07 +0100
Subject: remoteproc: avoid stack overflow in debugfs file

From: Arnd Bergmann <[email protected]>

commit 92792e48e2ae6051af30468a87994b5432da2f06 upstream.

Recent gcc versions warn about reading from a negative offset of an on-stack array:

drivers/remoteproc/remoteproc_debugfs.c: In function 'rproc_recovery_write':
drivers/remoteproc/remoteproc_debugfs.c:167:9: warning: 'buf[4294967295u]' may be used uninitialized in this function [-Wmaybe-uninitialized]

I don't see anything in sys_write() that prevents us from being called with a zero 'count' argument, so we should add an extra check in rproc_recovery_write() to prevent the access and avoid the warning.

---
 drivers/remoteproc/remoteproc_debugfs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -156,7 +156,7 @@ rproc_recovery_write(struct file *filp,
 	char buf[10];
 	int ret;
 
-	if (count > sizeof(buf))
+	if (count < 1 || count > sizeof(buf))
 		return count;
 
 	ret = copy_from_user(buf, user_buf, count);

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

queue-4.3/remoteproc-avoid-stack-overflow-in-debugfs-file.patch