From: Jiri Olsa <[email protected]> Stephane reported a possible issue in the ordered events code, which could lead to allocating more memory than guarded by max_alloc_size.
He also suggested the fix to properly check that the new size is below the max_alloc_size limit. Reported-by: Stephane Eranian <[email protected]> Suggested-by: Stephane Eranian <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: David Ahern <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/ordered-events.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/ordered-events.c b/tools/perf/util/ordered-events.c index 84ce25272c13..1904e7f6ec84 100644 --- a/tools/perf/util/ordered-events.c +++ b/tools/perf/util/ordered-events.c @@ -101,6 +101,7 @@ static struct ordered_event *alloc_event(struct ordered_events *oe, struct list_head *cache = &oe->cache; struct ordered_event *new = NULL; union perf_event *new_event; + size_t size; new_event = dup_event(oe, event); if (!new_event) @@ -133,6 +134,8 @@ static struct ordered_event *alloc_event(struct ordered_events *oe, * Removal of ordered event object moves it from events to * the cache list. */ + size = sizeof(*oe->buffer) + MAX_SAMPLE_BUFFER * sizeof(*new); + if (!list_empty(cache)) { new = list_entry(cache->next, struct ordered_event, list); list_del(&new->list); @@ -140,10 +143,7 @@ static struct ordered_event *alloc_event(struct ordered_events *oe, new = &oe->buffer->event[oe->buffer_idx]; if (++oe->buffer_idx == MAX_SAMPLE_BUFFER) oe->buffer = NULL; - } else if (oe->cur_alloc_size < oe->max_alloc_size) { - size_t size = sizeof(*oe->buffer) + - MAX_SAMPLE_BUFFER * sizeof(*new); - + } else if ((oe->cur_alloc_size + size) < oe->max_alloc_size) { oe->buffer = malloc(size); if (!oe->buffer) { free_dup_event(oe, new_event); -- 2.14.4
