Messages in this thread Patch in this message | | | Date | Thu, 16 Jun 2022 12:43:40 +0200 | Subject | Re: [PATCH] hinic: Replace memcpy() with direct assignment | From | "Gustavo A. R. Silva" <> |
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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@davemloft.net> > Cc: Eric Dumazet <edumazet@google.com> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> > Cc: Nathan Chancellor <nathan@kernel.org> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Cc: Tom Rix <trix@redhat.com> > Cc: Leon Romanovsky <leon@kernel.org> > Cc: Jiri Pirko <jiri@nvidia.com> > Cc: Vladimir Oltean <olteanv@gmail.com> > Cc: Simon Horman <simon.horman@corigine.com> > Cc: netdev@vger.kernel.org > 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>
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 ||
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