Messages in this thread Patch in this message | | | From | Cody Schafer <> | Subject | [PATCH v3] perf: prevent overflow in size calculation | Date | Thu, 19 Jul 2012 20:05:25 -0700 |
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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 | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index 8069dfb..d88693e 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -426,7 +426,18 @@ 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(struct sym_hist)) / sizeof(u64)) + return -1; + + sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64)); + + /* Check for overflow in zalloc argument */ + if (sizeof_sym_hist > (SIZE_MAX - sizeof(*notes->src)) + / symbol_conf.nr_events) + return -1; notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist); if (notes->src == NULL) -- 1.7.9.5
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