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Subject[PATCH] perf: prevent overflow in size calculation
Date
A large enough symbol size causes an overflow in the size parameter to the
histogram allocation, leading to a segfault in symbol__inc_addr_samples later
on when this histogram is accessed.

In the case of being called via perf-report, this returns back and
gracefully ignores the sample, eventually ignoring the chained return
value of perf_session_deliver_event in flush_sample_queue.

Signed-off-by: Cody Schafer <cody@linux.vnet.ibm.com>
---
tools/perf/util/annotate.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 8069dfb..6f78f20 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -426,8 +426,13 @@ int symbol__alloc_hist(struct symbol *sym)
{
struct annotation *notes = symbol__annotation(sym);
const size_t size = symbol__size(sym);
- size_t sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
+ size_t sizeof_sym_hist;

+ /* Check for overflow when calculating sizeof_sym_hist */
+ if (size > (SIZE_MAX / sizeof(u64)))
+ return -1;
+
+ sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist);
if (notes->src == NULL)
return -1;
--
1.7.9.5


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