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From: toddpoynor@google.com (Todd Poynor)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: backtrace: avoid crash on large invalid fp value
Date: Tue,  9 Oct 2012 23:46:12 -0700	[thread overview]
Message-ID: <1349851572-9967-1-git-send-email-toddpoynor@google.com> (raw)

Invalid frame pointer (signed) -4 <= fp <= -1 defeats check for too high
on overflow.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
---
 arch/arm/kernel/stacktrace.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index 00f79e5..6315162 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -31,7 +31,7 @@ int notrace unwind_frame(struct stackframe *frame)
 	high = ALIGN(low, THREAD_SIZE);
 
 	/* check current frame pointer is within bounds */
-	if (fp < (low + 12) || fp + 4 >= high)
+	if (fp < (low + 12) || fp >= high - 4)
 		return -EINVAL;
 
 	/* restore the registers from the stack frame */
-- 
1.7.7.3

             reply	other threads:[~2012-10-10  6:46 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-10  6:46 Todd Poynor [this message]
2012-10-10 11:15 ` [PATCH] ARM: backtrace: avoid crash on large invalid fp value Dave Martin
2012-11-02 23:47   ` Colin Cross
2012-11-05 10:54     ` Dave Martin
2012-11-09  2:05       ` Colin Cross
2012-11-09 10:56         ` Dave Martin
2012-11-09 18:17           ` Colin Cross
2012-11-13  9:49             ` Dave Martin
  -- strict thread matches above, loose matches on Subject: below --
2012-05-08  7:49 Todd Poynor

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