@@ -95,7 +95,7 @@ struct ima_template_entry {
u8 digest[TPM_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
struct ima_template_desc *template_desc; /* template descriptor */
u32 template_data_len;
- struct ima_field_data template_data[0]; /* template related data */
+ struct ima_field_data template_data[]; /* template related data */
};
struct ima_queue_entry {
@@ -103,7 +103,7 @@ struct ima_digest_data {
} ng;
u8 data[2];
} xattr;
- u8 digest[0];
+ u8 digest[];
} __packed;
/*
@@ -115,7 +115,7 @@ struct signature_v2_hdr {
uint8_t hash_algo; /* Digest algorithm [enum hash_algo] */
__be32 keyid; /* IMA key identifier - not X509/PGP specific */
__be16 sig_size; /* signature size */
- uint8_t sig[0]; /* signature payload */
+ uint8_t sig[]; /* signature payload */
} __packed;
/* integrity data associated with an inode */
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- security/integrity/ima/ima.h | 2 +- security/integrity/integrity.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)