Re: [PATCH] hinic: Replace memcpy() with direct assignment
From: Gustavo A. R. Silva
Date: Thu Jun 16 2022 - 07:06:24 EST
On 6/16/22 07:23, Kees Cook wrote:
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.
Also, there is a sanity check just before the for() loop:
38 if (fw_image->fw_info.fw_section_cnt > MAX_FW_TYPE_NUM) {
39 dev_err(&priv->hwdev->hwif->pdev->dev, "Wrong fw_type_num read from file, fw_type_num: 0x%x\n ",
40 fw_image->fw_info.fw_section_cnt);
41 return false;
42 }
so, this should be fine.
Avoid the whole thing and just do a direct assignment. This results in
no change to the executable code.
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Cc: Leon Romanovsky <leon@xxxxxxxxxx>
Cc: Jiri Pirko <jiri@xxxxxxxxxx>
Cc: Vladimir Oltean <olteanv@xxxxxxxxx>
Cc: Simon Horman <simon.horman@xxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
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>
Thanks
--
Gustavo
---
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 60ae8bfc5f69..1749d26f4bef 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 ||