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From:   Kees Cook <keescook@chromium.org>
To:     Christian Lamparter <chunkeey@googlemail.com>
Cc:     Kees Cook <keescook@chromium.org>, Kalle Valo <kvalo@kernel.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        linux-wireless@vger.kernel.org, linux-hardening@vger.kernel.org,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev
Subject: [PATCH] wifi: p54: Annotate struct p54_cal_database with __counted_by
Date:   Fri,  6 Oct 2023 13:17:20 -0700
Message-Id: <20231006201719.work.356-kees@kernel.org>
MIME-Version: 1.0
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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@googlemail.com>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 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
-- 
2.34.1