[ 01/26] b43: stop format string leaking into error msgs

From: Greg Kroah-Hartman
Date: Tue Jun 18 2013 - 12:39:07 EST


From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook@xxxxxxxxxxxx>

commit e0e29b683d6784ef59bbc914eac85a04b650e63c upstream.

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@xxxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/b43/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -2449,7 +2449,7 @@ static void b43_request_firmware(struct
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;


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