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 <stable@xxxxxxxxxxxxxxx> know about it.
>From 5ed386ec09a5d75bcf073967e55e895c2607a5c3 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <jroedel@xxxxxxx>
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 <jroedel@xxxxxxx>
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.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: fe3d197f84319 ('x86, mpx: On-demand kernel allocation of bounds tables')
Link: http://lkml.kernel.org/r/1491488362-27198-1-git-send-email-joro@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/mpx.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -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 jroedel@xxxxxxx are
queue-4.9/x86-mpx-correctly-report-do_mpx_bt_fault-failures-to-user-space.patch