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| author | Xiu Jianfeng <xiujianfeng@huawei.com> | 2022-05-27 14:17:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-22 11:21:22 +0300 |
| commit | a92d44b412e75dd66543843165e46637457f22cc (patch) | |
| tree | 143820f9a6d235cfe663f960fadc7e2300731c78 /security | |
| parent | 8c41ab0ecda85f984a889626184ef4487e36cde5 (diff) | |
| download | linux-a92d44b412e75dd66543843165e46637457f22cc.tar.xz | |
Revert "evm: Fix memleak in init_desc"
commit 51dd64bb99e4478fc5280171acd8e1b529eadaf7 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/evm/evm_crypto.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index 0450d79afdc8..b862f0f919bf 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); } |