Hi,
> -----Original Message-----
> From: zhenwei pi <[email protected]>
> Sent: Sunday, December 21, 2025 10:43 AM
> To: [email protected]
> Cc: [email protected]; Gonglei (Arei) <[email protected]>;
> [email protected]; [email protected]; zhenwei pi
> <[email protected]>; zhenwei pi <[email protected]>
> Subject: [PATCH v2 2/2] cryptodev-builtin: Limit the maximum size
>
> From: zhenwei pi <[email protected]>
>
> This backend driver is used for demonstration purposes only, unlimited size
> leads
> QEMU OOM.
>
> Fixes: CVE-2025-14876
Actually, I don't think this fix has anything to do with the CVE. You can
consider it an improvement.
> Fixes: 1653a5f3fc7 ("cryptodev: introduce a new cryptodev backend")
> Reported-by: 이재영 <[email protected]>
> Signed-off-by: zhenwei pi <[email protected]>
> ---
> backends/cryptodev-builtin.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/backends/cryptodev-builtin.c b/backends/cryptodev-builtin.c index
> 0414c01e06..55a3fbd27b 100644
> --- a/backends/cryptodev-builtin.c
> +++ b/backends/cryptodev-builtin.c
> @@ -53,6 +53,8 @@ typedef struct CryptoDevBackendBuiltinSession {
>
> #define CRYPTODEV_BUITLIN_MAX_AUTH_KEY_LEN 512
> #define CRYPTODEV_BUITLIN_MAX_CIPHER_KEY_LEN 64
> +/* demonstration purposes only, use a limited size to avoid QEMU OOM */
> +#define CRYPTODEV_BUITLIN_MAX_REQUEST_SIZE (1024 * 1024)
>
> struct CryptoDevBackendBuiltin {
> CryptoDevBackend parent_obj;
> @@ -98,12 +100,7 @@ static void cryptodev_builtin_init(
> 1u <<
> QCRYPTODEV_BACKEND_SERVICE_TYPE_MAC;
> backend->conf.cipher_algo_l = 1u << VIRTIO_CRYPTO_CIPHER_AES_CBC;
> backend->conf.hash_algo = 1u << VIRTIO_CRYPTO_HASH_SHA1;
> - /*
> - * Set the Maximum length of crypto request.
> - * Why this value? Just avoid to overflow when
> - * memory allocation for each crypto request.
> - */
> - backend->conf.max_size = LONG_MAX - sizeof(CryptoDevBackendOpInfo);
> + backend->conf.max_size = CRYPTODEV_BUITLIN_MAX_REQUEST_SIZE;
> backend->conf.max_cipher_key_len =
> CRYPTODEV_BUITLIN_MAX_CIPHER_KEY_LEN;
> backend->conf.max_auth_key_len =
> CRYPTODEV_BUITLIN_MAX_AUTH_KEY_LEN;
> cryptodev_builtin_init_akcipher(backend);
> --
> 2.43.0
