0121-w: Clamp maxcmd to the MIN/MAX_CMD_WIDTH range.

The current checks allow out-of-range values (for example, if
getenv/atoi returns ~-2GB, maxcmd becomes ~+2GB after the subtraction).
This is not a security problem, none of this is under an attacker's
control.
This commit is contained in:
Qualys Security Advisory 1970-01-01 00:00:00 +00:00 committed by Craig Small
parent e24804a9de
commit eaec2d0977

11
w.c
View File

@ -626,11 +626,14 @@ int main(int argc, char **argv)
maxcmd = atoi(p);
else
maxcmd = MAX_CMD_WIDTH;
if (MAX_CMD_WIDTH < maxcmd)
maxcmd = MAX_CMD_WIDTH;
#define CLAMP_CMD_WIDTH(cw) do { \
if ((cw) < MIN_CMD_WIDTH) (cw) = MIN_CMD_WIDTH; \
if ((cw) > MAX_CMD_WIDTH) (cw) = MAX_CMD_WIDTH; \
} while (0)
CLAMP_CMD_WIDTH(maxcmd);
maxcmd -= 21 + userlen + (from ? fromlen : 0) + (longform ? 20 : 0);
if (maxcmd < MIN_CMD_WIDTH)
maxcmd = MIN_CMD_WIDTH;
CLAMP_CMD_WIDTH(maxcmd);
#undef CLAMP_CMD_WIDTH
if (header) {