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authorXiu Jianfeng <xiujianfeng@huawei.com>2022-05-27 19:17:26 +0800
committerMimi Zohar <zohar@linux.ibm.com>2022-06-15 14:03:47 -0400
commit51dd64bb99e4478fc5280171acd8e1b529eadaf7 (patch)
tree8f0854f67dd34036d7e6bf4ca9fe5b7e07001c67 /security/integrity/evm
parentb13baccc3850ca8b8cccbf8ed9912dbaa0fdf7f3 (diff)
downloadlinux-51dd64bb99e4478fc5280171acd8e1b529eadaf7.tar.bz2
Revert "evm: Fix memleak in init_desc"
This reverts commit ccf11dbaa07b328fa469415c362d33459c140a37. Commit ccf11dbaa07b ("evm: Fix memleak in init_desc") said there is memleak in init_desc. That may be incorrect, as we can see, tmp_tfm is saved in one of the two global variables hmac_tfm or evm_tfm[hash_algo], then if init_desc is called next time, there is no need to alloc tfm again, so in the error path of kmalloc desc or crypto_shash_init(desc), It is not a problem without freeing tmp_tfm. And also that commit did not reset the global variable to NULL after freeing tmp_tfm and this makes *tfm a dangling pointer which may cause a UAF issue. Reported-by: Guozihua (Scott) <guozihua@huawei.com> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security/integrity/evm')
-rw-r--r--security/integrity/evm/evm_crypto.c7
1 files changed, 2 insertions, 5 deletions
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index a733aff02006..708de9656bbd 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -75,7 +75,7 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
{
long rc;
const char *algo;
- struct crypto_shash **tfm, *tmp_tfm = NULL;
+ struct crypto_shash **tfm, *tmp_tfm;
struct shash_desc *desc;
if (type == EVM_XATTR_HMAC) {
@@ -120,16 +120,13 @@ unlock:
alloc:
desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
GFP_KERNEL);
- if (!desc) {
- crypto_free_shash(tmp_tfm);
+ if (!desc)
return ERR_PTR(-ENOMEM);
- }
desc->tfm = *tfm;
rc = crypto_shash_init(desc);
if (rc) {
- crypto_free_shash(tmp_tfm);
kfree(desc);
return ERR_PTR(rc);
}