Function ima_eventdigest_init() can call 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: 9fab303a2cb3 ("ima: fix violation measurement list record")
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@xxxxxxxxxx>
---
security/integrity/ima/ima_template_lib.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 4183956c53af..0e627eac9c33 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -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);
--
2.45.2
