2023-09-16 02:21:45

by Kees Cook

Subject: [PATCH] wifi: ipw2x00: Annotate struct libipw_txb 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 libipw_txb.

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

Cc: Stanislav Yakovlev <[email protected]>
Cc: Kalle Valo <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/net/wireless/intel/ipw2x00/libipw.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/ipw2x00/libipw.h b/drivers/net/wireless/intel/ipw2x00/libipw.h
index bec7bc273748..9065ca5b0208 100644
--- a/drivers/net/wireless/intel/ipw2x00/libipw.h
+++ b/drivers/net/wireless/intel/ipw2x00/libipw.h
@@ -488,7 +488,7 @@ struct libipw_txb {
u8 reserved;
u16 frag_size;
u16 payload_size;
- struct sk_buff *fragments[];
+ struct sk_buff *fragments[] __counted_by(nr_frags);
};

/* SWEEP TABLE ENTRIES NUMBER */
--
2.34.1

2023-09-21 22:33:22

by Kalle Valo

Subject: Re: [PATCH] wifi: ipw2x00: Annotate struct libipw_txb with __counted_by

Kees Cook <[email protected]> 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 libipw_txb.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Stanislav Yakovlev <[email protected]>
> Cc: Kalle Valo <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> Reviewed-by: Gustavo A. R. Silva <[email protected]>

Patch applied to wireless-next.git, thanks.

357be7ebba38 wifi: ipw2x00: Annotate struct libipw_txb with __counted_by

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches