From: Gustavo A. R. Silva Date: Thu, 8 Aug 2024 22:04:59 +0000 (-0600) Subject: integrity: Use static_assert() to check struct sizes X-Git-Tag: v6.12~25^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=08ae3e5f5fc8edb9bd0c7ef9696ff29ef18b26ef;p=thirdparty%2Fkernel%2Flinux.git integrity: Use static_assert() to check struct sizes Commit 38aa3f5ac6d2 ("integrity: Avoid -Wflex-array-member-not-at-end warnings") introduced tagged `struct evm_ima_xattr_data_hdr` and `struct ima_digest_data_hdr`. We want to ensure that when new members need to be added to the flexible structures, they are always included within these tagged structs. So, we use `static_assert()` to ensure that the memory layout for both the flexible structure and the tagged struct is the same after any changes. Signed-off-by: Gustavo A. R. Silva Tested-by: Roberto Sassu Reviewed-by: Roberto Sassu Signed-off-by: Mimi Zohar --- diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 660f76cb69d37..c2c2da6911233 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -37,6 +37,8 @@ struct evm_ima_xattr_data { ); u8 data[]; } __packed; +static_assert(offsetof(struct evm_ima_xattr_data, data) == sizeof(struct evm_ima_xattr_data_hdr), + "struct member likely outside of __struct_group()"); /* Only used in the EVM HMAC code. */ struct evm_xattr { @@ -65,6 +67,8 @@ struct ima_digest_data { ); u8 digest[]; } __packed; +static_assert(offsetof(struct ima_digest_data, digest) == sizeof(struct ima_digest_data_hdr), + "struct member likely outside of __struct_group()"); /* * Instead of wrapping the ima_digest_data struct inside a local structure