Thanks for the feedback Jarkko.Including Gustavo in the CC list as they are the maintainer of the corresponding KSPP issue.
On 2022/5/24 4:17, Jarkko Sakkinen wrote:
On Mon, May 23, 2022 at 09:41:55AM +0800, GUO Zihua wrote:Use struct_size helper for calculating size of flexible struct, following the best practice. Reference: https://lore.kernel.org/all/CAHk-=wiGWjxs7EVUpccZEi6esvjpHJdgHQ=vtUeJ5crL62hx9A@xxxxxxxxxxxxxx/ 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@xxxxxxxxxx>Instead """ Link: https://lore.kernel.org/all/CAHk-=wiGWjxs7EVUpccZEi6esvjpHJdgHQ=vtUeJ5crL62hx9A@xxxxxxxxxxxxxx/ Signed-off-by: GUO Zihua <guozihua@xxxxxxxxxx> """ You should split this into two patches as said in https://www.kernel.org/doc/html/latest/process/submitting-patches.html#separate-your-changes Also these are bug fixes and the commit message does not contain any description of the issue, e.g.
Thing is, it's not fixing any bug per se. It's a cleanup patch, updating codes calculating size of a variable-sized structure to the best practice. Should I still separate the patch in this case.
""" When issuing CF='-Wflexible-array-sizeof' make C=2 security/keys/encrypted-keys/encrypted.o the following is observed: security/keys/encrypted-keys/encrypted.c:670:28: warning: using sizeof on a flexible structure security/keys/encrypted-keys/encrypted.c: note: in included file: """ And then explain why struct_size() addresses this issue, and provide Fixes tag.
Struct_size is a macro that make use of sizeof under the hood. So struct_size does not actually address these warnings. However, the usage of struct_size for calculating size of variable-sized structure is suggested by Linus as the best pratice.
--- 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.cindex 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;--2.36.0BR, Jarkko .
-- Best GUO Zihua
