ima: fix buffer overrun in ima_eventdigest_init_common

Function ima_eventdigest_init() calls ima_eventdigest_init_common()
with HASH_ALGO__LAST which is then used to access the array
hash_digest_size[] leading to buffer overrun. Have a conditional
statement to handle this.

Fixes: 9fab303a2c ("ima: fix violation measurement list record")
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
Tested-by: Enrico Bravi (PhD at polito.it) <enrico.bravi@huawei.com>
Cc: stable@vger.kernel.org # 5.19+
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Samasth Norway Ananda 2024-08-07 10:27:13 -07:00 committed by Mimi Zohar
parent 8cf0b93919
commit 923168a063

View File

@ -318,15 +318,21 @@ static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
hash_algo_name[hash_algo]);
}
if (digest)
if (digest) {
memcpy(buffer + offset, digest, digestsize);
else
} else {
/*
* If digest is NULL, the event being recorded is a violation.
* Make room for the digest by increasing the offset by the
* hash algorithm digest size.
* hash algorithm digest size. If the hash algorithm is not
* specified increase the offset by IMA_DIGEST_SIZE which
* fits SHA1 or MD5
*/
offset += hash_digest_size[hash_algo];
if (hash_algo < HASH_ALGO__LAST)
offset += hash_digest_size[hash_algo];
else
offset += IMA_DIGEST_SIZE;
}
return ima_write_template_field_data(buffer, offset + digestsize,
fmt, field_data);