wifi: rtw89: fw: validate multi-firmware header before accessing

[ Upstream commit 1f0efffd597893404aea5c3d4f1bdaa1c61d4434 ]

A firmeware file contains multi-firmware with a header to represent
contents. The mfw_hdr->fw_nr is to define number of firmware in file.

         +-----+-------+------+---------+--------------+
         | sig | fw_nr | rsvd | version | reserved     |
         +---------------------------------------------+ --
 fw 0    | cv | type | mp | rsvd | shift | size | rsvd |   \
         +---------------------------------------------+   |
 fw 1    | cv | type | mp | rsvd | shift | size | rsvd |   | mfw_hdr->fw_nr
         +---------------------------------------------+   |
 fw N-1  |                  ...                        |   /
         +=============================================+ --
         |               fw 0 content                  |
         |       (pointed by fw0 shift/size)           |
         +=============================================+

To avoid Coverity warning, validate header is in range of firmware size,
and also validate the range of actual firmware content is in range.

Addresses-Coverity-ID: 1494046 ("Untrusted loop bound")

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250203072911.47313-4-pkshih@realtek.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ping-Ke Shih
2025-02-03 15:29:10 +08:00
committed by Greg Kroah-Hartman
parent f4c99c7b71
commit 01edf9255f

View File

@@ -501,6 +501,30 @@ static int rtw89_fw_hdr_parser(struct rtw89_dev *rtwdev,
}
}
static int rtw89_mfw_validate_hdr(struct rtw89_dev *rtwdev,
const struct firmware *firmware,
const struct rtw89_mfw_hdr *mfw_hdr)
{
const void *mfw = firmware->data;
u32 mfw_len = firmware->size;
u8 fw_nr = mfw_hdr->fw_nr;
const void *ptr;
if (fw_nr == 0) {
rtw89_err(rtwdev, "mfw header has no fw entry\n");
return -ENOENT;
}
ptr = &mfw_hdr->info[fw_nr];
if (ptr > mfw + mfw_len) {
rtw89_err(rtwdev, "mfw header out of address\n");
return -EFAULT;
}
return 0;
}
static
int rtw89_mfw_recognize(struct rtw89_dev *rtwdev, enum rtw89_fw_type type,
struct rtw89_fw_suit *fw_suit, bool nowarn)
@@ -511,6 +535,7 @@ int rtw89_mfw_recognize(struct rtw89_dev *rtwdev, enum rtw89_fw_type type,
u32 mfw_len = firmware->size;
const struct rtw89_mfw_hdr *mfw_hdr = (const struct rtw89_mfw_hdr *)mfw;
const struct rtw89_mfw_info *mfw_info = NULL, *tmp;
int ret;
int i;
if (mfw_hdr->sig != RTW89_MFW_SIG) {
@@ -523,6 +548,10 @@ int rtw89_mfw_recognize(struct rtw89_dev *rtwdev, enum rtw89_fw_type type,
return 0;
}
ret = rtw89_mfw_validate_hdr(rtwdev, firmware, mfw_hdr);
if (ret)
return ret;
for (i = 0; i < mfw_hdr->fw_nr; i++) {
tmp = &mfw_hdr->info[i];
if (tmp->type != type)
@@ -552,6 +581,12 @@ int rtw89_mfw_recognize(struct rtw89_dev *rtwdev, enum rtw89_fw_type type,
found:
fw_suit->data = mfw + le32_to_cpu(mfw_info->shift);
fw_suit->size = le32_to_cpu(mfw_info->size);
if (fw_suit->data + fw_suit->size > mfw + mfw_len) {
rtw89_err(rtwdev, "fw_suit %d out of address\n", type);
return -EFAULT;
}
return 0;
}