hinic: Replace memcpy() with direct assignment

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@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Link: https://github.com/ClangBuiltLinux/linux/issues/1592
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
Link: https://lore.kernel.org/r/20220616052312.292861-1-keescook@chromium.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_devlink.c b/drivers/net/ethernet/huawei/hinic/hinic_devlink.c
index 60ae8bf..1749d26 100644 (file)
--- 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 ||