-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.

There is currently an object (`hdr)` in `struct ima_max_digest_data`
that contains a flexible structure (`struct ima_digest_data`):

 struct ima_max_digest_data {
        struct ima_digest_data hdr;
        u8 digest[HASH_MAX_DIGESTSIZE];
 } __packed;

So, in order to avoid ending up with a flexible-array member in the
middle of another struct, we use the `struct_group_tagged()` helper to
separate the flexible array from the rest of the members in the flexible
structure:

struct ima_digest_data {
        struct_group_tagged(ima_digest_data_hdr, hdr,

        ... the rest of the members

        );
        u8 digest[];
} __packed;

With the change described above, we can now declare an object of the
type of the tagged struct, without embedding the flexible array in the
middle of another struct:

 struct ima_max_digest_data {
        struct ima_digest_data_hdr hdr;
        u8 digest[HASH_MAX_DIGESTSIZE];
 } __packed;

We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure.

So, with these changes, fix the following warnings:

security/integrity/evm/evm.h:45:32: warning: structure containing a flexible 
array member is not at the end of another structure 
[-Wflex-array-member-not-at-end]
security/integrity/evm/evm.h:45:32: warning: structure containing a flexible 
array member is not at the end of another structure 
[-Wflex-array-member-not-at-end]
security/integrity/evm/evm.h:45:32: warning: structure containing a flexible 
array member is not at the end of another structure 
[-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavo...@kernel.org>
---
 security/integrity/ima/ima_api.c          |  6 ++++--
 security/integrity/ima/ima_appraise.c     |  4 +++-
 security/integrity/ima/ima_init.c         |  6 ++++--
 security/integrity/ima/ima_main.c         |  6 ++++--
 security/integrity/ima/ima_template_lib.c | 10 ++++++----
 security/integrity/integrity.h            |  4 +++-
 6 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index b37d043d5748..c7c8d1bffb17 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -247,6 +247,8 @@ int ima_collect_measurement(struct ima_iint_cache *iint, 
struct file *file,
        struct inode *real_inode = d_real_inode(file_dentry(file));
        const char *filename = file->f_path.dentry->d_name.name;
        struct ima_max_digest_data hash;
+       struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
+                                               struct ima_digest_data, hdr);
        struct kstat stat;
        int result = 0;
        int length;
@@ -286,9 +288,9 @@ int ima_collect_measurement(struct ima_iint_cache *iint, 
struct file *file,
                        result = -ENODATA;
                }
        } else if (buf) {
-               result = ima_calc_buffer_hash(buf, size, &hash.hdr);
+               result = ima_calc_buffer_hash(buf, size, hash_hdr);
        } else {
-               result = ima_calc_file_hash(file, &hash.hdr);
+               result = ima_calc_file_hash(file, hash_hdr);
        }
 
        if (result && result != -EBADF && result != -EINVAL)
diff --git a/security/integrity/ima/ima_appraise.c 
b/security/integrity/ima/ima_appraise.c
index 3497741caea9..656c709b974f 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -378,7 +378,9 @@ static int xattr_verify(enum ima_hooks func, struct 
ima_iint_cache *iint,
                }
 
                rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo,
-                                      iint->ima_hash->digest, &hash.hdr);
+                                      iint->ima_hash->digest,
+                                      container_of(&hash.hdr,
+                                              struct ima_digest_data, hdr));
                if (rc) {
                        *cause = "sigv3-hashing-error";
                        *status = INTEGRITY_FAIL;
diff --git a/security/integrity/ima/ima_init.c 
b/security/integrity/ima/ima_init.c
index 393f5c7912d5..4e208239a40e 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -48,12 +48,14 @@ static int __init ima_add_boot_aggregate(void)
        struct ima_event_data event_data = { .iint = iint,
                                             .filename = boot_aggregate_name };
        struct ima_max_digest_data hash;
+       struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
+                                               struct ima_digest_data, hdr);
        int result = -ENOMEM;
        int violation = 0;
 
        memset(iint, 0, sizeof(*iint));
        memset(&hash, 0, sizeof(hash));
-       iint->ima_hash = &hash.hdr;
+       iint->ima_hash = hash_hdr;
        iint->ima_hash->algo = ima_hash_algo;
        iint->ima_hash->length = hash_digest_size[ima_hash_algo];
 
@@ -70,7 +72,7 @@ static int __init ima_add_boot_aggregate(void)
         * is not found.
         */
        if (ima_tpm_chip) {
-               result = ima_calc_boot_aggregate(&hash.hdr);
+               result = ima_calc_boot_aggregate(hash_hdr);
                if (result < 0) {
                        audit_cause = "hashing_error";
                        goto err_out;
diff --git a/security/integrity/ima/ima_main.c 
b/security/integrity/ima/ima_main.c
index c84e8c55333d..0d3a7c864fd4 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -941,6 +941,8 @@ int process_buffer_measurement(struct mnt_idmap *idmap,
                                            .buf_len = size};
        struct ima_template_desc *template;
        struct ima_max_digest_data hash;
+       struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
+                                               struct ima_digest_data, hdr);
        char digest_hash[IMA_MAX_DIGEST_SIZE];
        int digest_hash_len = hash_digest_size[ima_hash_algo];
        int violation = 0;
@@ -979,7 +981,7 @@ int process_buffer_measurement(struct mnt_idmap *idmap,
        if (!pcr)
                pcr = CONFIG_IMA_MEASURE_PCR_IDX;
 
-       iint.ima_hash = &hash.hdr;
+       iint.ima_hash = hash_hdr;
        iint.ima_hash->algo = ima_hash_algo;
        iint.ima_hash->length = hash_digest_size[ima_hash_algo];
 
@@ -990,7 +992,7 @@ int process_buffer_measurement(struct mnt_idmap *idmap,
        }
 
        if (buf_hash) {
-               memcpy(digest_hash, hash.hdr.digest, digest_hash_len);
+               memcpy(digest_hash, hash_hdr->digest, digest_hash_len);
 
                ret = ima_calc_buffer_hash(digest_hash, digest_hash_len,
                                           iint.ima_hash);
diff --git a/security/integrity/ima/ima_template_lib.c 
b/security/integrity/ima/ima_template_lib.c
index 6cd0add524cd..74198d7619da 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -339,6 +339,8 @@ int ima_eventdigest_init(struct ima_event_data *event_data,
                         struct ima_field_data *field_data)
 {
        struct ima_max_digest_data hash;
+       struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
+                                               struct ima_digest_data, hdr);
        u8 *cur_digest = NULL;
        u32 cur_digestsize = 0;
        struct inode *inode;
@@ -358,7 +360,7 @@ int ima_eventdigest_init(struct ima_event_data *event_data,
        if ((const char *)event_data->filename == boot_aggregate_name) {
                if (ima_tpm_chip) {
                        hash.hdr.algo = HASH_ALGO_SHA1;
-                       result = ima_calc_boot_aggregate(&hash.hdr);
+                       result = ima_calc_boot_aggregate(hash_hdr);
 
                        /* algo can change depending on available PCR banks */
                        if (!result && hash.hdr.algo != HASH_ALGO_SHA1)
@@ -368,7 +370,7 @@ int ima_eventdigest_init(struct ima_event_data *event_data,
                                memset(&hash, 0, sizeof(hash));
                }
 
-               cur_digest = hash.hdr.digest;
+               cur_digest = hash_hdr->digest;
                cur_digestsize = hash_digest_size[HASH_ALGO_SHA1];
                goto out;
        }
@@ -379,14 +381,14 @@ int ima_eventdigest_init(struct ima_event_data 
*event_data,
        inode = file_inode(event_data->file);
        hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
            ima_hash_algo : HASH_ALGO_SHA1;
-       result = ima_calc_file_hash(event_data->file, &hash.hdr);
+       result = ima_calc_file_hash(event_data->file, hash_hdr);
        if (result) {
                integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
                                    event_data->filename, "collect_data",
                                    "failed", result, 0);
                return result;
        }
-       cur_digest = hash.hdr.digest;
+       cur_digest = hash_hdr->digest;
        cur_digestsize = hash.hdr.length;
 out:
        return ima_eventdigest_init_common(cur_digest, cur_digestsize,
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 50d6f798e613..fc1952da02ea 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -44,6 +44,7 @@ struct evm_xattr {
 #define IMA_MAX_DIGEST_SIZE    HASH_MAX_DIGESTSIZE
 
 struct ima_digest_data {
+       struct_group_tagged(ima_digest_data_hdr, hdr,
        u8 algo;
        u8 length;
        union {
@@ -57,6 +58,7 @@ struct ima_digest_data {
                } ng;
                u8 data[2];
        } xattr;
+       );
        u8 digest[];
 } __packed;
 
@@ -65,7 +67,7 @@ struct ima_digest_data {
  * with the maximum hash size, define ima_max_digest_data struct.
  */
 struct ima_max_digest_data {
-       struct ima_digest_data hdr;
+       struct ima_digest_data_hdr hdr;
        u8 digest[HASH_MAX_DIGESTSIZE];
 } __packed;
 
-- 
2.34.1


Reply via email to