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| author | Jiri Olsa <jolsa@kernel.org> | 2018-09-07 12:24:55 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-09-19 10:25:08 -0300 |
| commit | 53da12e013498c4eca592939bb18a5dbd1d228c9 (patch) | |
| tree | d9aa254252a13e629f54dee1c24bd4f12e52ac0d /tools/perf/util/ordered-events.c | |
| parent | d5ceb62b36545b597e89adb5eb778c3e15431c10 (diff) | |
| download | lwn-53da12e013498c4eca592939bb18a5dbd1d228c9.tar.gz lwn-53da12e013498c4eca592939bb18a5dbd1d228c9.zip | |
perf ordered_events: Prevent crossing max_alloc_size
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 <eranian@google.com>
Suggested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180907102455.7030-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/ordered-events.c')
| -rw-r--r-- | tools/perf/util/ordered-events.c | 8 |
1 files 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); |