[PATCH AUTOSEL 5.15 37/41] hinic: Replace memcpy() with direct assignment

[Sasha Levin]

From: Kees Cook <keescook@xxxxxxxxxxxx>

[ Upstream commit 1e70212e031528918066a631c9fdccda93a1ffaa ]

Under CONFIG_FORTIFY_SOURCE=y and CONFIG_UBSAN_BOUNDS=y, Clang is bugged
here for calculating the size of the destination buffer (0x10 instead of
0x14). This copy is a fixed size (sizeof(struct fw_section_info_st)), with
the source and dest being struct fw_section_info_st, so the memcpy should
be safe, assuming the index is within bounds, which is UBSAN_BOUNDS's
responsibility to figure out.

Avoid the whole thing and just do a direct assignment. This results in
no change to the executable code.

[This is a duplicate of commit 2c0ab32b73cf ("hinic: Replace memcpy()
 with direct assignment") which was applied to net-next.]

Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Cc: llvm@xxxxxxxxxxxxxxx
Link: https://github.com/ClangBuiltLinux/linux/issues/1592
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx> # build
Link: https://lore.kernel.org/r/20220616052312.292861-1-keescook@xxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/huawei/hinic/hinic_devlink.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_devlink.c b/drivers/net/ethernet/huawei/hinic/hinic_devlink.c
index 6e11ee339f12..92d4e0039565 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_devlink.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_devlink.c
@@ -43,9 +43,7 @@ static bool check_image_valid(struct hinic_devlink_priv *priv, const u8 *buf,
 
 	for (i = 0; i < fw_image->fw_info.fw_section_cnt; i++) {
 		len += fw_image->fw_section_info[i].fw_section_len;
-		memcpy(&host_image->image_section_info[i],
-		       &fw_image->fw_section_info[i],
-		       sizeof(struct fw_section_info_st));
+		host_image->image_section_info[i] = fw_image->fw_section_info[i];
 	}
 
 	if (len != fw_image->fw_len ||
-- 
2.35.1