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authorAdrian Hunter <adrian.hunter@intel.com>2013-08-27 11:23:04 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-08-29 15:10:02 -0300
commit03b6ea9b91e0914caa847a1ade759af549555298 (patch)
treec06dc11a4e6d2f95c51dd9f1160d392cbef45a82 /tools/perf
parent314add6b1f045b59ca39683bd0cbc5310cd203f2 (diff)
downloadlinux-03b6ea9b91e0914caa847a1ade759af549555298.tar.gz
perf evsel: Tidy up sample parsing overflow checking
The size of data retrieved from a sample event must be validated to ensure it does not go past the end of the event. That was being done sporadically and without considering integer overflows. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/evsel.c112
1 files changed, 71 insertions, 41 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 47cbe1e58b73..9a5fb23ff8e2 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1131,24 +1131,30 @@ static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
return 0;
}
-static bool sample_overlap(const union perf_event *event,
- const void *offset, u64 size)
+static inline bool overflow(const void *endp, u16 max_size, const void *offset,
+ u64 size)
{
- const void *base = event;
+ return size > max_size || offset + size > endp;
+}
- if (offset + size > base + event->header.size)
- return true;
+#define OVERFLOW_CHECK(offset, size, max_size) \
+ do { \
+ if (overflow(endp, (max_size), (offset), (size))) \
+ return -EFAULT; \
+ } while (0)
- return false;
-}
+#define OVERFLOW_CHECK_u64(offset) \
+ OVERFLOW_CHECK(offset, sizeof(u64), sizeof(u64))
int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
struct perf_sample *data)
{
u64 type = evsel->attr.sample_type;
- u64 regs_user = evsel->attr.sample_regs_user;
bool swapped = evsel->needs_swap;
const u64 *array;
+ u16 max_size = event->header.size;
+ const void *endp = (void *)event + max_size;
+ u64 sz;
/*
* used for cross-endian analysis. See git commit 65014ab3
@@ -1170,6 +1176,11 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
array = event->sample.array;
+ /*
+ * The evsel's sample_size is based on PERF_SAMPLE_MASK which includes
+ * up to PERF_SAMPLE_PERIOD. After that overflow() must be used to
+ * check the format does not go past the end of the event.
+ */
if (evsel->sample_size + sizeof(event->header) > event->header.size)
return -EFAULT;
@@ -1235,6 +1246,7 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
if (type & PERF_SAMPLE_READ) {
u64 read_format = evsel->attr.read_format;
+ OVERFLOW_CHECK_u64(array);
if (read_format & PERF_FORMAT_GROUP)
data->read.group.nr = *array;
else
@@ -1243,41 +1255,51 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
array++;
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+ OVERFLOW_CHECK_u64(array);
data->read.time_enabled = *array;
array++;
}
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+ OVERFLOW_CHECK_u64(array);
data->read.time_running = *array;
array++;
}
/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
if (read_format & PERF_FORMAT_GROUP) {
- data->read.group.values = (struct sample_read_value *) array;
- array = (void *) array + data->read.group.nr *
- sizeof(struct sample_read_value);
+ const u64 max_group_nr = UINT64_MAX /
+ sizeof(struct sample_read_value);
+
+ if (data->read.group.nr > max_group_nr)
+ return -EFAULT;
+ sz = data->read.group.nr *
+ sizeof(struct sample_read_value);
+ OVERFLOW_CHECK(array, sz, max_size);
+ data->read.group.values =
+ (struct sample_read_value *)array;
+ array = (void *)array + sz;
} else {
+ OVERFLOW_CHECK_u64(array);
data->read.one.id = *array;
array++;
}
}
if (type & PERF_SAMPLE_CALLCHAIN) {
- if (sample_overlap(event, array, sizeof(data->callchain->nr)))
- return -EFAULT;
-
- data->callchain = (struct ip_callchain *)array;
+ const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);
- if (sample_overlap(event, array, data->callchain->nr))
+ OVERFLOW_CHECK_u64(array);
+ data->callchain = (struct ip_callchain *)array++;
+ if (data->callchain->nr > max_callchain_nr)
return -EFAULT;
-
- array += 1 + data->callchain->nr;
+ sz = data->callchain->nr * sizeof(u64);
+ OVERFLOW_CHECK(array, sz, max_size);
+ array = (void *)array + sz;
}
if (type & PERF_SAMPLE_RAW) {
- const u64 *pdata;
-
+ OVERFLOW_CHECK_u64(array);
u.val64 = *array;
if (WARN_ONCE(swapped,
"Endianness of raw data not corrected!\n")) {
@@ -1286,65 +1308,73 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
u.val32[0] = bswap_32(u.val32[0]);
u.val32[1] = bswap_32(u.val32[1]);
}
-
- if (sample_overlap(event, array, sizeof(u32)))
- return -EFAULT;
-
data->raw_size = u.val32[0];
- pdata = (void *) array + sizeof(u32);
-
- if (sample_overlap(event, pdata, data->raw_size))
- return -EFAULT;
+ array = (void *)array + sizeof(u32);
- data->raw_data = (void *) pdata;
-
- array = (void *)array + data->raw_size + sizeof(u32);
+ OVERFLOW_CHECK(array, data->raw_size, max_size);
+ data->raw_data = (void *)array;
+ array = (void *)array + data->raw_size;
}
if (type & PERF_SAMPLE_BRANCH_STACK) {
- u64 sz;
+ const u64 max_branch_nr = UINT64_MAX /
+ sizeof(struct branch_entry);
- data->branch_stack = (struct branch_stack *)array;
- array++; /* nr */
+ OVERFLOW_CHECK_u64(array);
+ data->branch_stack = (struct branch_stack *)array++;
+ if (data->branch_stack->nr > max_branch_nr)
+ return -EFAULT;
sz = data->branch_stack->nr * sizeof(struct branch_entry);
- sz /= sizeof(u64);
- array += sz;
+ OVERFLOW_CHECK(array, sz, max_size);
+ array = (void *)array + sz;
}
if (type & PERF_SAMPLE_REGS_USER) {
+ u64 avail;
+
/* First u64 tells us if we have any regs in sample. */
- u64 avail = *array++;
+ OVERFLOW_CHECK_u64(array);
+ avail = *array++;
if (avail) {
+ u64 regs_user = evsel->attr.sample_regs_user;
+
+ sz = hweight_long(regs_user) * sizeof(u64);
+ OVERFLOW_CHECK(array, sz, max_size);
data->user_regs.regs = (u64 *)array;
- array += hweight_long(regs_user);
+ array = (void *)array + sz;
}
}
if (type & PERF_SAMPLE_STACK_USER) {
- u64 size = *array++;
+ OVERFLOW_CHECK_u64(array);
+ sz = *array++;
data->user_stack.offset = ((char *)(array - 1)
- (char *) event);
- if (!size) {
+ if (!sz) {
data->user_stack.size = 0;
} else {
+ OVERFLOW_CHECK(array, sz, max_size);
data->user_stack.data = (char *)array;
- array += size / sizeof(*array);
+ array = (void *)array + sz;
+ OVERFLOW_CHECK_u64(array);
data->user_stack.size = *array++;
}
}
data->weight = 0;
if (type & PERF_SAMPLE_WEIGHT) {
+ OVERFLOW_CHECK_u64(array);
data->weight = *array;
array++;
}
data->data_src = PERF_MEM_DATA_SRC_NONE;
if (type & PERF_SAMPLE_DATA_SRC) {
+ OVERFLOW_CHECK_u64(array);
data->data_src = *array;
array++;
}