Commit ea5b41f9 authored Dec 09, 2009 by Tony Luck Committed by Ingo Molnar Dec 10, 2009

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 <tony.luck@intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: luming.yu@intel.com
LKML-Reference: <4b2024d085302c2a2@agluck-desktop.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 722d0172

kernel/lockdep.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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 </rant>
		*/
		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;