CVE-2021-3764 (published 2022-08-23T16:15Z)

A memory leak flaw was found in the Linux kernel's ccp_run_aes_gcm_cmd() function that allows an attacker to cause a denial of service. The vulnerability is similar to the older CVE-2019-18808. The highest threat from this vulnerability is to system availability.

CVSS v3 base score: 5.5, MEDIUM (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)

Weakness information:
cwe_id: CWE-401
cwe_name: Missing Release of Memory after Effective Lifetime
description: The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.
extended_description: This is often triggered by improper handling of malformed data or unexpectedly interrupted sessions.  In some languages, developers are responsible for tracking memory allocation and releasing the memory.  If there are no more pointers or references to the memory, then it can no longer be tracked and identified for release.
         

Fix information:
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Dan Carpenter
author_date: 2021-08-26 16:04:27+03:00
msg: crypto: ccp - fix resource leaks in ccp_run_aes_gcm_cmd()

There are three bugs in this code:

1) If we ccp_init_data() fails for &src then we need to free aad.
   Use goto e_aad instead of goto e_ctx.
2) The label to free the &final_wa was named incorrectly as "e_tag" but
   it should have been "e_final_wa".  One error path leaked &final_wa.
3) The &tag was leaked on one error path.  In that case, I added a free
   before the goto because the resource was local to that block.

Fixes: 36cf515b9bbe ("crypto: ccp - Enable support for AES GCM on v5 CCPs")
Reported-by: "minihanshen(沈明航)" <minihanshen@tencent.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: John Allen <john.allen@amd.com>
Tested-by: John Allen <john.allen@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: ccp-ops.c
change_type: ModificationType.MODIFY
diff: @@ -778,7 +778,7 @@ ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 				    in_place ? DMA_BIDIRECTIONAL
 					     : DMA_TO_DEVICE);
 		if (ret)
-			goto e_ctx;
+			goto e_aad;
 
 		if (in_place) {
 			dst = src;
@@ -863,7 +863,7 @@ ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 	op.u.aes.size = 0;
 	ret = cmd_q->ccp->vdata->perform->aes(&op);
 	if (ret)
-		goto e_dst;
+		goto e_final_wa;
 
 	if (aes->action == CCP_AES_ACTION_ENCRYPT) {
 		/* Put the ciphered tag after the ciphertext. */
@@ -873,17 +873,19 @@ ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 		ret = ccp_init_dm_workarea(&tag, cmd_q, authsize,
 					   DMA_BIDIRECTIONAL);
 		if (ret)
-			goto e_tag;
+			goto e_final_wa;
 		ret = ccp_set_dm_area(&tag, 0, p_tag, 0, authsize);
-		if (ret)
-			goto e_tag;
+		if (ret) {
+			ccp_dm_free(&tag);
+			goto e_final_wa;
+		}
 
 		ret = crypto_memneq(tag.address, final_wa.address,
 				    authsize) ? -EBADMSG : 0;
 		ccp_dm_free(&tag);
 	}
 
-e_tag:
+e_final_wa:
 	ccp_dm_free(&final_wa);
 
 e_dst:

programming_language: C