Commit 9be260a6 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Linus Torvalds
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prevent kprobes from catching spurious page faults



Prevent kprobes from catching spurious faults which will cause infinite
recursive page-fault and memory corruption by stack overflow.
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 767b5828
......@@ -603,8 +603,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
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_regs *regs, unsigned long error_code)
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_regs *regs, unsigned long error_code)
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
......
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