b43: stop format string leaking into error msgs

The module parameter "fwpostfix" is userspace controllable, unfiltered,
and is used to define the firmware filename. b43_do_request_fw() populates
ctx->errors[] on error, containing the firmware filename. b43err()
parses its arguments as a format string. For systems with b43 hardware,
this could lead to a uid-0 to ring-0 escalation.

CVE-2013-2852

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Kees Cook 2013-05-10 14:48:21 -07:00 committed by John W. Linville
parent 5efac94999
commit e0e29b683d

View File

@ -2458,7 +2458,7 @@ static void b43_request_firmware(struct work_struct *work)
for (i = 0; i < B43_NR_FWTYPES; i++) {
errmsg = ctx->errors[i];
if (strlen(errmsg))
b43err(dev->wl, errmsg);
b43err(dev->wl, "%s", errmsg);
}
b43_print_fw_helptext(dev->wl, 1);
goto out;