| Message ID | 20230929180746.3005922-5-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 18cee9da32cdabd1cd9344e1369cd8adcc14d022 |
| Headers | show |
| Series | mlxsw: Annotate structs with __counted_by | expand |
On Fri, Sep 29, 2023 at 11:07:44AM -0700, Kees Cook wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct mlxsw_sp_span. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > 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: Ido Schimmel <idosch@nvidia.com> Thanks for taking care of that
On Fri, Sep 29, 2023 at 11:08 AM Kees Cook <keescook@chromium.org> wrote: > > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct mlxsw_sp_span. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > 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> > --- Great patch! Crucially, span->entries_count is assigned before any flexible array accesses. span->entries_count = entries_count; ... for (i = 0; i < mlxsw_sp->span->entries_count; i++) mlxsw_sp->span->entries[i].id = i; Reviewed-by: Justin Stitt <justinstitt@google.com> > drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c > index b3472fb94617..af50ff9e5f26 100644 > --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c > +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c > @@ -31,7 +31,7 @@ struct mlxsw_sp_span { > refcount_t policer_id_base_ref_count; > atomic_t active_entries_count; > int entries_count; > - struct mlxsw_sp_span_entry entries[]; > + struct mlxsw_sp_span_entry entries[] __counted_by(entries_count); > }; > > struct mlxsw_sp_span_analyzed_port { > -- > 2.34.1 > > Thanks Justin
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c index b3472fb94617..af50ff9e5f26 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c @@ -31,7 +31,7 @@ struct mlxsw_sp_span { refcount_t policer_id_base_ref_count; atomic_t active_entries_count; int entries_count; - struct mlxsw_sp_span_entry entries[]; + struct mlxsw_sp_span_entry entries[] __counted_by(entries_count); }; struct mlxsw_sp_span_analyzed_port {
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct mlxsw_sp_span. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci 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> --- drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)