From: Ping-Ke Shih pkshih@realtek.com
[ 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 --- drivers/net/wireless/realtek/rtw89/fw.c | 35 +++++++++++++++++++++++++ 1 file changed, 35 insertions(+)
diff --git a/drivers/net/wireless/realtek/rtw89/fw.c b/drivers/net/wireless/realtek/rtw89/fw.c index aed0647955d8e..1fbcba718998f 100644 --- a/drivers/net/wireless/realtek/rtw89/fw.c +++ b/drivers/net/wireless/realtek/rtw89/fw.c @@ -539,6 +539,30 @@ 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) @@ -549,6 +573,7 @@ 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) { @@ -561,6 +586,10 @@ 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) @@ -590,6 +619,12 @@ 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; }