Messages in this thread | | | Date | Mon, 26 Sep 2022 20:10:11 -0500 | From | "Gustavo A. R. Silva" <> | Subject | Re: [PATCH] mlxsw: core_acl_flex_actions: Split memcpy() of struct flow_action_cookie flexible array |
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On Mon, Sep 26, 2022 at 05:40:33PM -0700, Kees Cook wrote: > To work around a misbehavior of the compiler's ability to see into > composite flexible array structs (as detailed in the coming memcpy() > hardening series[1]), split the memcpy() of the header and the payload > so no false positive run-time overflow warning will be generated. > > [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org > > Cc: Ido Schimmel <idosch@nvidia.com> > Cc: Petr Machata <petrm@nvidia.com> > 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: netdev@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks! -- Gustavo
> --- > drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c b/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c > index 636db9a87457..9dfe7148199f 100644 > --- a/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c > +++ b/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c > @@ -737,8 +737,9 @@ mlxsw_afa_cookie_create(struct mlxsw_afa *mlxsw_afa, > if (!cookie) > return ERR_PTR(-ENOMEM); > refcount_set(&cookie->ref_count, 1); > - memcpy(&cookie->fa_cookie, fa_cookie, > - sizeof(*fa_cookie) + fa_cookie->cookie_len); > + cookie->fa_cookie = *fa_cookie; > + memcpy(cookie->fa_cookie.cookie, fa_cookie->cookie, > + fa_cookie->cookie_len); > > err = rhashtable_insert_fast(&mlxsw_afa->cookie_ht, &cookie->ht_node, > mlxsw_afa_cookie_ht_params); > -- > 2.34.1 >
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