From: Akinobu Mita Date: Wed, 2 Mar 2011 11:35:28 +0000 (+0900) Subject: wusb: fix find_first_zero_bit() return value check X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=962f3ffa927f2e777a4193843c45ffa6e52ff4b6;p=linux-beck.git wusb: fix find_first_zero_bit() return value check In wusb_cluster_id_get(), if no zero bits exist in wusb_cluster_id_table, find_first_zero_bit() returns CLUSTER_IDS. But it is impossible to detect that the bitmap is full because there is an off-by-one error in the return value check. It will cause unexpected memory access by setting bit out of wusb_cluster_id_table bitmap, and caller will get wrong cluster id. Signed-off-by: Akinobu Mita Cc: linux-usb@vger.kernel.org Cc: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/wusbcore/wusbhc.c b/drivers/usb/wusbcore/wusbhc.c index 2054d4ee9774..0faca16df765 100644 --- a/drivers/usb/wusbcore/wusbhc.c +++ b/drivers/usb/wusbcore/wusbhc.c @@ -320,7 +320,7 @@ u8 wusb_cluster_id_get(void) u8 id; spin_lock(&wusb_cluster_ids_lock); id = find_first_zero_bit(wusb_cluster_id_table, CLUSTER_IDS); - if (id > CLUSTER_IDS) { + if (id >= CLUSTER_IDS) { id = 0; goto out; }