2023-09-23 01:38:37

by Kees Cook

Subject: [PATCH] ALSA: hda: Annotate struct hda_conn_list with __counted_by

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 hda_conn_list.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Cezary Rojewski <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
sound/pci/hda/hda_codec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 33af707a65ab..01718b1fc9a7 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -88,7 +88,7 @@ struct hda_conn_list {
struct list_head list;
int len;
hda_nid_t nid;
- hda_nid_t conns[];
+ hda_nid_t conns[] __counted_by(len);
};

/* look up the cached results */
--
2.34.1

2023-09-23 12:23:14

by Gustavo A. R. Silva

Subject: Re: [PATCH] ALSA: hda: Annotate struct hda_conn_list with __counted_by

On 9/22/23 11:50, 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 hda_conn_list.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Jaroslav Kysela <[email protected]>
> Cc: Takashi Iwai <[email protected]>
> Cc: Cezary Rojewski <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> sound/pci/hda/hda_codec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> index 33af707a65ab..01718b1fc9a7 100644
> --- a/sound/pci/hda/hda_codec.c
> +++ b/sound/pci/hda/hda_codec.c
> @@ -88,7 +88,7 @@ struct hda_conn_list {
> struct list_head list;
> int len;
> hda_nid_t nid;
> - hda_nid_t conns[];
> + hda_nid_t conns[] __counted_by(len);
> };
>
> /* look up the cached results */

2023-09-23 15:31:39

by Takashi Iwai

Subject: Re: [PATCH] ALSA: hda: Annotate struct hda_conn_list with __counted_by

On Fri, 22 Sep 2023 19:50:42 +0200,
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 hda_conn_list.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Jaroslav Kysela <[email protected]>
> Cc: Takashi Iwai <[email protected]>
> Cc: Cezary Rojewski <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Applied now. Thanks.


Takashi