Re: [PATCH] wifi: p54: Annotate struct p54_cal_database with __counted_by

From: Gustavo A. R. Silva
Date: Fri Oct 06 2023 - 19:03:05 EST




On 10/6/23 22:17, 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 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 p54_cal_database.

Cc: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: linux-hardening@xxxxxxxxxxxxxxx
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>


Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks!
--
Gustavo

---
drivers/net/wireless/intersil/p54/p54.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intersil/p54/p54.h b/drivers/net/wireless/intersil/p54/p54.h
index 3356ea708d81..770e348d1f6c 100644
--- a/drivers/net/wireless/intersil/p54/p54.h
+++ b/drivers/net/wireless/intersil/p54/p54.h
@@ -126,7 +126,7 @@ struct p54_cal_database {
size_t entry_size;
size_t offset;
size_t len;
- u8 data[];
+ u8 data[] __counted_by(entries);
};
#define EEPROM_READBACK_LEN 0x3fc