diff options
| -rw-r--r-- | src/xz/util.c | 10 | ||||
| -rw-r--r-- | src/xzdec/xzdec.c | 13 |
2 files changed, 19 insertions, 4 deletions
diff --git a/src/xz/util.c b/src/xz/util.c index deb5dcc2..19f5eee3 100644 --- a/src/xz/util.c +++ b/src/xz/util.c @@ -56,11 +56,17 @@ str_to_uint64(const char *name, const char *value, uint64_t min, uint64_t max) do { // Don't overflow. - if (result > (UINT64_MAX - 9) / 10) + if (result > UINT64_MAX / 10) goto error; result *= 10; - result += *value - '0'; + + // Another overflow check + const uint32_t add = *value - '0'; + if (UINT64_MAX - add < result) + goto error; + + result += add; ++value; } while (*value >= '0' && *value <= '9'); diff --git a/src/xzdec/xzdec.c b/src/xzdec/xzdec.c index 8518d362..7f2e0fdc 100644 --- a/src/xzdec/xzdec.c +++ b/src/xzdec/xzdec.c @@ -153,6 +153,9 @@ memlimit_init(void) /// \brief Convert a string to uint64_t /// /// This is rudely copied from src/xz/util.c and modified a little. :-( +/// Since this function is used only for parsing the memory usage limit, +/// this cheats a little and saturates too big values to UINT64_MAX instead +/// of giving an error. /// /// \param max Return value when the string "max" was specified. /// @@ -173,11 +176,17 @@ str_to_uint64(const char *value, uint64_t max) do { // Don't overflow. - if (result > (UINT64_MAX - 9) / 10) + if (result > UINT64_MAX / 10) return UINT64_MAX; result *= 10; - result += *value - '0'; + + // Another overflow check + const uint32_t add = *value - '0'; + if (UINT64_MAX - add < result) + return UINT64_MAX; + + result += add; ++value; } while (*value >= '0' && *value <= '9'); |