From: Leon Yen Date: Thu, 9 Oct 2025 02:01:58 +0000 (+0800) Subject: wifi: mt76: mt7921: fix a potential clc buffer length underflow X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5373f8b19e568b5c217832b9bbef165bd2b2df14;p=thirdparty%2Flinux.git wifi: mt76: mt7921: fix a potential clc buffer length underflow The buf_len is used to limit the iterations for retrieving the country power setting and may underflow under certain conditions due to changes in the power table in CLC. This underflow leads to an almost infinite loop or an invalid power setting resulting in driver initialization failure. Cc: stable@vger.kernel.org Fixes: fa6ad88e023d ("wifi: mt76: mt7921: fix country count limitation for CLC") Signed-off-by: Leon Yen Signed-off-by: Ming Yen Hsieh Link: https://patch.msgid.link/20251009020158.1923429-1-mingyen.hsieh@mediatek.com Signed-off-by: Felix Fietkau --- diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c index 833d0ab642303..8442dbd2ee23f 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c @@ -1353,6 +1353,9 @@ int __mt7921_mcu_set_clc(struct mt792x_dev *dev, u8 *alpha2, u16 len = le16_to_cpu(rule->len); u16 offset = len + sizeof(*rule); + if (buf_len < offset) + break; + pos += offset; buf_len -= offset; if (rule->alpha2[0] != alpha2[0] ||