From ea5b41f9d595be354f7a50e56b28c2d72e6e88a5 Mon Sep 17 00:00:00 2001 From: "Luck, Tony" Date: Wed, 9 Dec 2009 14:29:36 -0800 Subject: [PATCH] lockdep: Avoid out of bounds array reference in save_trace() ia64 found this the hard way (because we currently have a stub for save_stack_trace() that does nothing). But it would be a good idea to be cautious in case a real save_stack_trace() bailed out with an error before it set trace->nr_entries. Signed-off-by: Tony Luck Acked-by: Peter Zijlstra Cc: luming.yu@intel.com LKML-Reference: <4b2024d085302c2a2@agluck-desktop.sc.intel.com> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 7a3ae56..4f8df01 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -386,7 +386,8 @@ static int save_trace(struct stack_trace *trace) * complete trace that maxes out the entries provided will be reported * as incomplete, friggin useless */ - if (trace->entries[trace->nr_entries-1] == ULONG_MAX) + if (trace->nr_entries != 0 && + trace->entries[trace->nr_entries-1] == ULONG_MAX) trace->nr_entries--; trace->max_entries = trace->nr_entries; -- 2.7.4