On Wed, 2022-05-25 at 09:26 +0800, GUO Zihua wrote:
> Use struct_size helper for calculating size of flexible struct, following
> the best practice.
>
> Note: HASH_SIZE here is a SHA256_DIGEST_SIZE whoes value is 32, so
~~~~~
> adding 1 should be fine here.
Where? '1' is without a context. I don't really know how to interpret
this sentence.
>
> Link: https://lore.kernel.org/all/CAHk-=wiGWjxs7EVUpccZEi6esvjpHJdgHQ=vtUeJ5crL62hx9A@xxxxxxxxxxxxxx/
> Signed-off-by: GUO Zihua <guozihua@xxxxxxxxxx>
>
> ---
>
> v3:
> Update commit message format according to Jarkko's feedback.
> v2:
> Update the commit message, removing the part about "potential issue"
> following Jarkko's suggestion.
>
> ---
> security/keys/encrypted-keys/encrypted.c | 7 +++++--
> security/keys/user_defined.c | 2 +-
> 2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
> index e05cfc2e49ae..37349580e855 100644
> --- a/security/keys/encrypted-keys/encrypted.c
> +++ b/security/keys/encrypted-keys/encrypted.c
> @@ -613,6 +613,7 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
> long dlen;
> int i;
> int ret;
> + size_t epayload_datalen = 0;
>
> ret = kstrtol(datalen, 10, &dlen);
> if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE)
> @@ -667,8 +668,10 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
> if (ret < 0)
> return ERR_PTR(ret);
>
> - epayload = kzalloc(sizeof(*epayload) + payload_datalen +
> - datablob_len + HASH_SIZE + 1, GFP_KERNEL);
> + epayload_datalen = size_add(payload_datalen, datablob_len);
> + epayload_datalen = size_add(epayload_datalen, HASH_SIZE + 1);
> + epayload = kzalloc(struct_size(epayload, payload_data,
> + epayload_datalen), GFP_KERNEL);
> if (!epayload)
> return ERR_PTR(-ENOMEM);
>
> diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
> index 749e2a4dcb13..334fed36e9f3 100644
> --- a/security/keys/user_defined.c
> +++ b/security/keys/user_defined.c
> @@ -64,7 +64,7 @@ int user_preparse(struct key_preparsed_payload *prep)
> if (datalen <= 0 || datalen > 32767 || !prep->data)
> return -EINVAL;
>
> - upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
> + upayload = kmalloc(struct_size(upayload, data, datalen), GFP_KERNEL);
> if (!upayload)
> return -ENOMEM;
>
BR, Jarkko
