[PATCH 3.4 25/32] HID: picolcd_core: validate output report details

Greg Kroah-Hartman
2013-12-06T21:54:27Z

From: Kees Cook <keescook@chromium.org>

commit 1e87a2456b0227ca4ab881e19a11bb99d164e792 upstream.

A HID device could send a malicious output report that would cause the
picolcd HID driver to trigger a NULL dereference during attr file writing.

[jkosina@suse.cz: changed

report->maxfield < 1

to

report->maxfield != 1

as suggested by Bruno].

CVE-2013-2899

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@kernel.org
Reviewed-by: Bruno Prémont <bonbons@linux-vserver.org>
Acked-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
[Kefeng: backported to stable 3.4: adjust filename]
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hid/hid-picolcd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hid/hid-picolcd.c
+++ b/drivers/hid/hid-picolcd.c
@@ -1424,7 +1424,7 @@ static ssize_t picolcd_operation_mode_st
buf += 10;
cnt -= 10;
}
- if (!report)
+ if (!report || report->maxfield != 1)
return -EINVAL;

while (cnt > 0 && (buf[cnt-1] == '\n' || buf[cnt-1] == '\r'))