The patch titled
x86: prevent kprobes from catching spurious page faults
has been added to the -mm tree. Its filename is
x86-prevent-kprobes-from-catching-spurious-page-faults.patch
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Subject: x86: prevent kprobes from catching spurious page faults
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Prevent kprobes from catching spurious faults which will cause infinite
recursive page-fault and memory corruption by stack overflow.
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Jim Keniston <jkenisto@xxxxxxxxxx>
Cc: "Frank Ch. Eigler" <fche@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxx> [2.6.28.x]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/fault.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff -puN arch/x86/mm/fault.c~x86-prevent-kprobes-from-catching-spurious-page-faults arch/x86/mm/fault.c
--- a/arch/x86/mm/fault.c~x86-prevent-kprobes-from-catching-spurious-page-faults
+++ a/arch/x86/mm/fault.c
@@ -603,8 +603,6 @@ void __kprobes do_page_fault(struct pt_r
si_code = SEGV_MAPERR;
- if (notify_page_fault(regs))
- return;
if (unlikely(kmmio_fault(regs, address)))
return;
@@ -634,6 +632,9 @@ void __kprobes do_page_fault(struct pt_r
if (spurious_fault(address, error_code))
return;
+ /* kprobes don't want to hook the spurious faults. */
+ if (notify_page_fault(regs))
+ return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
@@ -641,6 +642,9 @@ void __kprobes do_page_fault(struct pt_r
goto bad_area_nosemaphore;
}
+ /* kprobes don't want to hook the spurious faults. */
+ if (notify_page_fault(regs))
+ return;
/*
* It's safe to allow irq's after cr2 has been saved and the
_
Patches currently in -mm which might be from mhiramat@xxxxxxxxxx are
origin.patch
x86-prevent-kprobes-from-catching-spurious-page-faults.patch
kprobes-cleanup-aggr_kprobe-related-code.patch
kprobes-move-export_symbol_gpl-just-after-function-definitions.patch
kprobes-cleanup-comment-style-in-kprobesh.patch
kprobes-rename-kprobe_enabled-to-kprobes_all_disarmed.patch
kprobes-support-per-kprobe-disabling.patch
kprobes-support-kretprobe-and-jprobe-per-probe-disabling.patch
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