From: Laxman Acharya Padhya Date: Fri, 10 Jul 2026 17:25:03 +0000 (+0545) Subject: Bluetooth: btrtl: validate firmware patch bounds X-Git-Tag: v7.2-rc4~17^2~10^2~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=609c5b04a28dc1b0f3af6a7bc93055135b2d2059;p=thirdparty%2Fkernel%2Flinux.git Bluetooth: btrtl: validate firmware patch bounds rtlbt_parse_firmware() copies patch_length - 4 bytes before appending the firmware version. A malformed firmware patch shorter than the version field can make this subtraction underflow and turn the copy into an oversized read and write during Bluetooth setup. The existing patch_offset + patch_length check can also wrap on 32-bit architectures. Validate the patch length and range without arithmetic overflow before allocating or copying the patch. Fixes: db33c77dddc2 ("Bluetooth: btrtl: Create separate module for Realtek BT driver") Cc: stable@vger.kernel.org Signed-off-by: Laxman Acharya Padhya Signed-off-by: Luiz Augusto von Dentz --- diff --git a/drivers/bluetooth/btrtl.c b/drivers/bluetooth/btrtl.c index 49ecb18fea45..7f54d2d2d13a 100644 --- a/drivers/bluetooth/btrtl.c +++ b/drivers/bluetooth/btrtl.c @@ -797,8 +797,9 @@ static int rtlbt_parse_firmware(struct hci_dev *hdev, } BT_DBG("length=%x offset=%x index %d", patch_length, patch_offset, i); - min_size = patch_offset + patch_length; - if (btrtl_dev->fw_len < min_size) + if (patch_length < sizeof(epatch_info->fw_version) || + patch_offset > btrtl_dev->fw_len || + patch_length > btrtl_dev->fw_len - patch_offset) return -EINVAL; /* Copy the firmware into a new buffer and write the version at