| Message ID | 20220519024702.215223-1-guozihua@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | keys: Use struct_size and size_add helper with alloc | expand |
On Thu, May 19, 2022 at 10:47:02AM +0800, GUO Zihua wrote: > Use struct_size helper for calculating size of flexible struct to avoid > potential issues and improve readibility. Use size_add to calculate > addition of size to prevent potential issues. What issues? Please explicitly state the issues. BR, Jarkko
On 2022/5/20 4:49, Jarkko Sakkinen wrote: > On Thu, May 19, 2022 at 10:47:02AM +0800, GUO Zihua wrote: >> Use struct_size helper for calculating size of flexible struct to avoid >> potential issues and improve readibility. Use size_add to calculate >> addition of size to prevent potential issues. > > What issues? Please explicitly state the issues. > > BR, Jarkko > . Hi Jarkko, This is a clean-up/optimization patch mostly focuses on readability and no actual issue is observed at the moment.
On Fri, May 20, 2022 at 03:35:09PM +0800, Guozihua (Scott) wrote: > On 2022/5/20 4:49, Jarkko Sakkinen wrote: > > On Thu, May 19, 2022 at 10:47:02AM +0800, GUO Zihua wrote: > > > Use struct_size helper for calculating size of flexible struct to avoid > > > potential issues and improve readibility. Use size_add to calculate > > > addition of size to prevent potential issues. > > > > What issues? Please explicitly state the issues. > > > > BR, Jarkko > > . > > Hi Jarkko, > > This is a clean-up/optimization patch mostly focuses on readability and no > actual issue is observed at the moment. But the commit message is talking about potential issues. BR, Jarkko
On 2022/5/24 3:58, Jarkko Sakkinen wrote: > On Fri, May 20, 2022 at 03:35:09PM +0800, Guozihua (Scott) wrote: >> On 2022/5/20 4:49, Jarkko Sakkinen wrote: >>> On Thu, May 19, 2022 at 10:47:02AM +0800, GUO Zihua wrote: >>>> Use struct_size helper for calculating size of flexible struct to avoid >>>> potential issues and improve readibility. Use size_add to calculate >>>> addition of size to prevent potential issues. >>> >>> What issues? Please explicitly state the issues. >>> >>> BR, Jarkko >>> . >> >> Hi Jarkko, >> >> This is a clean-up/optimization patch mostly focuses on readability and no >> actual issue is observed at the moment. > > But the commit message is talking about potential issues. > > BR, Jarkko > . Thanks Jarkko. Yes, and it should be considered wrong. I've sent a v2 patch addressing this.
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;
Use struct_size helper for calculating size of flexible struct to avoid potential issues and improve readibility. Use size_add to calculate addition of size to prevent potential issues. Reference: https://lore.kernel.org/all/CAHk-=wiGWjxs7EVUpccZEi6esvjpHJdgHQ=vtUeJ5crL62hx9A@mail.gmail.com/ Note: HASH_SIZE here is a SHA256_DIGEST_SIZE whoes value is 32, so adding 1 should be fine here. Signed-off-by: GUO Zihua <guozihua@huawei.com> --- security/keys/encrypted-keys/encrypted.c | 7 +++++-- security/keys/user_defined.c | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-)