From: Jianglei Nie <[email protected]>
Line 36 (#1) allocates a memory chunk for scratch by kmalloc(), but
it is never freed through the function, which will lead to a memory
leak.
We should kfree() scratch before the function returns (#2, #3 and #4).
31 static int tpm2_key_encode(struct trusted_key_payload *payload,
32 struct trusted_key_options *options,
33 u8 *src, u32 len)
34 {
36 u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
// #1: kmalloc space
37 u8 *work = scratch, *work1;
50 if (!scratch)
51 return -ENOMEM;
56 if (options->blobauth_len == 0) {
60 if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
61 return PTR_ERR(w); // #2: missing kfree
63 }
71 if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
72 "BUG: scratch buffer is too small"))
73 return -EINVAL; // #3: missing kfree
// #4: missing kfree: scratch is never used afterwards.
82 if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
83 return PTR_ERR(work1);
85 return work1 - payload->blob;
86 }
Signed-off-by: Jianglei Nie <[email protected]>
---
security/keys/trusted-keys/trusted_tpm2.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 0165da386289..99bb8b2409ac 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -57,8 +57,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
unsigned char bool[3], *w = bool;
/* tag 0 is emptyAuth */
w = asn1_encode_boolean(w, w + sizeof(bool), true);
- if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
+ if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
+ kfree(scratch);
return PTR_ERR(w);
+ }
work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
}
@@ -69,8 +71,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
* trigger, so if it does there's something nefarious going on
*/
if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
- "BUG: scratch buffer is too small"))
+ "BUG: scratch buffer is too small")){
+ kfree(scratch);
return -EINVAL;
+ }
work = asn1_encode_integer(work, end_work, options->keyhandle);
work = asn1_encode_octet_string(work, end_work, pub, pub_len);
@@ -79,6 +83,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
+ kfree(scratch);
if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
return PTR_ERR(work1);
--
2.25.1