From: Colin Ian King <colin.king@canonical.com>
Date: Fri, 18 Jun 2021 00:54:53 +0000 (+0900)
Subject: ksmbd: fix kfree of uninitialized pointer oid
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5fb68864674faa3e0a4fc767c4a87f51ece218c6;p=linux.git

ksmbd: fix kfree of uninitialized pointer oid

Currently function ksmbd_neg_token_init_mech_type can kfree an
uninitialized pointer oid when the call to asn1_oid_decode fails when
vlen is out of range. All the other failure cases in function
asn1_oid_decode set *oid to NULL on an error, so fix the issue by
ensuring the vlen out of range error also nullifies the pointer.

Addresses-Coverity: ("Uninitialized pointer read")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/cifsd/asn1.c b/fs/cifsd/asn1.c
index 2c63a3e5618b9..b014f4638610c 100644
--- a/fs/cifsd/asn1.c
+++ b/fs/cifsd/asn1.c
@@ -66,7 +66,7 @@ static bool asn1_oid_decode(const unsigned char *value, size_t vlen,
 
 	vlen += 1;
 	if (vlen < 2 || vlen > UINT_MAX / sizeof(unsigned long))
-		return false;
+		goto fail_nullify;
 
 	*oid = kmalloc(vlen * sizeof(unsigned long), GFP_KERNEL);
 	if (!*oid)
@@ -102,6 +102,7 @@ static bool asn1_oid_decode(const unsigned char *value, size_t vlen,
 
 fail:
 	kfree(*oid);
+fail_nullify:
 	*oid = NULL;
 	return false;
 }