Patch "x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space" 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

x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space

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:
x86-mpx-correctly-report-do_mpx_bt_fault-failures-to-user-space.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: Joerg Roedel <[email protected]>
Date: Thu, 6 Apr 2017 16:19:22 +0200
Subject: x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space

From: Joerg Roedel <[email protected]>

commit 5ed386ec09a5d75bcf073967e55e895c2607a5c3 upstream.

When this function fails it just sends a SIGSEGV signal to user-space using force_sig(). This signal is missing essential information about the cause, e.g. the trap_nr or an error code.

Fix this by propagating the error to the only caller of mpx_handle_bd_fault(), do_bounds(), which sends the correct SIGSEGV signal to the process.

---
 arch/x86/mm/mpx.c |   10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

@@ -525,15 +525,7 @@ int mpx_handle_bd_fault(void)
 	if (!kernel_managing_mpx_tables(current->mm))
 		return -EINVAL;
 
-	if (do_mpx_bt_fault()) {
-		force_sig(SIGSEGV, current);
-		/*
-		 * The force_sig() is essentially "handling" this
-		 * exception, so we do not pass up the error
-		 * from do_mpx_bt_fault().
-		 */
-	}
-	return 0;
+	return do_mpx_bt_fault();
 }
 
 /*

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

queue-4.9/x86-mpx-correctly-report-do_mpx_bt_fault-failures-to-user-space.patch