ima: hashing large files bug fix

Hashing files larger than INT_MAX causes process to loop.
Dependent on redefining kernel_read() offset type to loff_t.

(http://bugzilla.kernel.org/show_bug.cgi?id=13909)

Cc: stable@kernel.org
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 63003a63aaee..46642a19bc78 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -45,9 +45,9 @@ int ima_calc_hash(struct file *file, char *digest)
 {
         struct hash_desc desc;
         struct scatterlist sg[1];
-        loff_t i_size;
+        loff_t i_size, offset = 0;
         char *rbuf;
-        int rc, offset = 0;
+        int rc;
 
         rc = init_desc(&desc);
         if (rc != 0)
@@ -67,6 +67,8 @@ int ima_calc_hash(struct file *file, char *digest)
                         rc = rbuf_len;
                         break;
                 }
+                if (rbuf_len == 0)
+                        break;
                 offset += rbuf_len;
                 sg_init_one(sg, rbuf, rbuf_len);