5.1-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 3.8.8 / ipc-set-msg-back-to-eagain-if-copy-wasn-t-performed.patch

From 2dc958fa2fe6987e7ab106bd97029a09a82fcd8d Mon Sep 17 00:00:00 2001
From: Stanislav Kinsbursky <skinsbursky@parallels.com>
Date: Mon, 1 Apr 2013 11:40:51 +0400
Subject: ipc: set msg back to -EAGAIN if copy wasn't performed

From: Stanislav Kinsbursky <skinsbursky@parallels.com>

commit 2dc958fa2fe6987e7ab106bd97029a09a82fcd8d upstream.

Make sure that msg pointer is set back to error value in case of
MSG_COPY flag is set and desired message to copy wasn't found.  This
garantees that msg is either a error pointer or a copy address.

Otherwise the last message in queue will be freed without unlinking from
the queue (which leads to memory corruption) and the dummy allocated
copy won't be released.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 ipc/msg.c |    1 +
 1 file changed, 1 insertion(+)

--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -872,6 +872,7 @@ long do_msgrcv(int msqid, void __user *b
 							goto out_unlock;
 						break;
 					}
+					msg = ERR_PTR(-EAGAIN);
 				} else
 					break;
 				msg_counter++;