This is a note to let you know that I've just added the patch titled
x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs
to the 3.17-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-asm-traps-disable-tracing-and-kprobes-in-fixup_bad_iret-and-sync_regs.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Date: Mon, 24 Nov 2014 17:39:06 -0800
Subject: x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs
From: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
commit 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 upstream.
These functions can be executed on the int3 stack, so kprobes
are dangerous. Tracing is probably a bad idea, too.
Fixes: b645af2d5905 ("x86_64, traps: Rework bad_iret")
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/traps.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -387,7 +387,7 @@ NOKPROBE_SYMBOL(do_int3);
* for scheduling or signal handling. The actual stack switch is done in
* entry.S
*/
-asmlinkage __visible struct pt_regs *sync_regs(struct pt_regs *eregs)
+asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs)
{
struct pt_regs *regs = eregs;
/* Did already sync */
@@ -413,7 +413,7 @@ struct bad_iret_stack {
struct pt_regs regs;
};
-asmlinkage __visible
+asmlinkage __visible notrace
struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
{
/*
@@ -436,6 +436,7 @@ struct bad_iret_stack *fixup_bad_iret(st
BUG_ON(!user_mode_vm(&new_stack->regs));
return new_stack;
}
+NOKPROBE_SYMBOL(fixup_bad_iret);
#endif
/*
Patches currently in stable-queue which might be from luto@xxxxxxxxxxxxxx are
queue-3.17/x86_64-switch_to-load-tls-descriptors-before-switching-ds-and-es.patch
queue-3.17/x86-asm-traps-disable-tracing-and-kprobes-in-fixup_bad_iret-and-sync_regs.patch
queue-3.17/x86-tls-disallow-unusual-tls-segments.patch
queue-3.17/x86-tls-validate-tls-entries-to-protect-espfix.patch
queue-3.17/x86-kvm-clear-paravirt_enabled-on-kvm-guests-for-espfix32-s-benefit.patch
--
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