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From:   Kees Cook <keescook@chromium.org>
To:     Bodo Stroesser <bostroesser@gmail.com>
Cc:     Kees Cook <keescook@chromium.org>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org, target-devel@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, linux-hardening@vger.kernel.org
Subject: [PATCH] scsi: target: tcmu: Annotate struct tcmu_tmr with __counted_by
Date:   Fri, 22 Sep 2023 10:53:01 -0700
Message-Id: <20230922175300.work.148-kees@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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 tcmu_tmr.

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

Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/target/target_core_user.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 22cc6cac0ba2..7eb94894bd68 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -201,7 +201,7 @@ struct tcmu_tmr {
 
 	uint8_t tmr_type;
 	uint32_t tmr_cmd_cnt;
-	int16_t tmr_cmd_ids[];
+	int16_t tmr_cmd_ids[] __counted_by(tmr_cmd_cnt);
 };
 
 /*
-- 
2.34.1