diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-06-07 22:39:53 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-06-10 18:56:01 -0300 |
| commit | e1a2c9d70b312acc262f6be936dd5bbd9bbc6236 (patch) | |
| tree | 48187c840c538e9aba022852acf95f6d2722f8a6 | |
| parent | ae75956c166fe169b8c137bf375305fc97820a62 (diff) | |
perf hwmon: Fix parse_hwmon_filename() strlcpy buffer overflow
parse_hwmon_filename() strips the "_alarm" suffix from event names
by copying into a 24-byte stack buffer:
strlcpy(fn_type, fn_item, fn_item_len - 5);
The third argument is the source length minus the suffix, not the
destination buffer capacity. A long event name ending in "_alarm"
can have fn_item_len - 5 > sizeof(fn_type), causing strlcpy() to
write past the 24-byte fn_type[] array. The assert() only validates
that the longest *valid* hwmon item fits, but does not protect
against crafted input.
Clamp the strlcpy size to min(fn_item_len - 5, sizeof(fn_type)).
Fixes: 4810b761f812da3c ("perf hwmon_pmu: Add hwmon filename parser")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/hwmon_pmu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c index fbfb872ceb18..bdcbe887579a 100644 --- a/tools/perf/util/hwmon_pmu.c +++ b/tools/perf/util/hwmon_pmu.c @@ -202,7 +202,8 @@ bool parse_hwmon_filename(const char *filename, fn_item_len = strlen(fn_item); if (fn_item_len > 6 && !strcmp(&fn_item[fn_item_len - 6], "_alarm")) { assert(strlen(LONGEST_HWMON_ITEM_STR) < sizeof(fn_type)); - strlcpy(fn_type, fn_item, fn_item_len - 5); + /* fn_item_len - 5 strips "_alarm"; clamp to buffer size */ + strlcpy(fn_type, fn_item, min_t(size_t, fn_item_len - 5, sizeof(fn_type))); fn_item = fn_type; *alarm = true; } |