Re: [v2 PATCH] crypto: drbg - Delete unused ctx from struct sdesc

[Gustavo A. R. Silva]

On 11/19/25 13:38, Herbert Xu wrote:

On Mon, Nov 10, 2025 at 07:44:56PM +0900, Gustavo A. R. Silva wrote:

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 511a27c91813..e9f9775c237f 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1442,9 +1442,12 @@ static void drbg_kcapi_set_entropy(struct crypto_rng 
*tfm,

#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)

  struct sdesc {
-       struct shash_desc shash;
-       char ctx[];
+       /* Must be last as it ends in a flexible-array member. */
+       TRAILING_OVERLAP(struct shash_desc, shash, __ctx,
+               char ctx[];
+       );
  };
+static_assert(offsetof(struct sdesc, shash.__ctx) == offsetof(struct sdesc, 
ctx));

This isn't even used.  Just delete it:

Awesome. :)

Thanks!
-Gustavo

---8<---
The ctx array in struct sdesc is never used.  Delete it as it's
bogus since the previous member ends with a flexible array.

Reported-by: Gustavo A. R. Silva <gustavo...@kernel.org>
Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 511a27c91813..1d433dae9955 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1443,7 +1443,6 @@ static void drbg_kcapi_set_entropy(struct crypto_rng *tfm,
  #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
  struct sdesc {
        struct shash_desc shash;
-       char ctx[];
  };

static int drbg_init_hash_kernel(struct drbg_state *drbg)