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authorNamjae Jeon <linkinjeon@kernel.org>2023-05-03 08:44:14 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-05-17 11:50:29 +0200
commit4f9baa06674910876ce3e0b5fbe23214690d731d (patch)
tree212fc2a48356b9ec967d5283c82a5f00a274ec3b /fs/ksmbd
parentbc77a6e933060e40a3f1efc564f6f6f1d11e93c1 (diff)
ksmbd: fix deadlock in ksmbd_find_crypto_ctx()
[ Upstream commit 7b4323373d844954bb76e0e9f39c4e5fc785fa7b ] Deadlock is triggered by sending multiple concurrent session setup requests. It should be reused after releasing when getting ctx for crypto. Multiple consecutive ctx uses cause deadlock while waiting for releasing due to the limited number of ctx. Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-20591 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/ksmbd')
-rw-r--r--fs/ksmbd/auth.c19
1 files changed, 11 insertions, 8 deletions
diff --git a/fs/ksmbd/auth.c b/fs/ksmbd/auth.c
index c1408e922fc6..59d205946746 100644
--- a/fs/ksmbd/auth.c
+++ b/fs/ksmbd/auth.c
@@ -220,22 +220,22 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn *conn, struct ksmbd_session *sess,
{
char ntlmv2_hash[CIFS_ENCPWD_SIZE];
char ntlmv2_rsp[CIFS_HMAC_MD5_HASH_SIZE];
- struct ksmbd_crypto_ctx *ctx;
+ struct ksmbd_crypto_ctx *ctx = NULL;
char *construct = NULL;
int rc, len;
- ctx = ksmbd_crypto_ctx_find_hmacmd5();
- if (!ctx) {
- ksmbd_debug(AUTH, "could not crypto alloc hmacmd5\n");
- return -ENOMEM;
- }
-
rc = calc_ntlmv2_hash(conn, sess, ntlmv2_hash, domain_name);
if (rc) {
ksmbd_debug(AUTH, "could not get v2 hash rc %d\n", rc);
goto out;
}
+ ctx = ksmbd_crypto_ctx_find_hmacmd5();
+ if (!ctx) {
+ ksmbd_debug(AUTH, "could not crypto alloc hmacmd5\n");
+ return -ENOMEM;
+ }
+
rc = crypto_shash_setkey(CRYPTO_HMACMD5_TFM(ctx),
ntlmv2_hash,
CIFS_HMAC_MD5_HASH_SIZE);
@@ -271,6 +271,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn *conn, struct ksmbd_session *sess,
ksmbd_debug(AUTH, "Could not generate md5 hash\n");
goto out;
}
+ ksmbd_release_crypto_ctx(ctx);
+ ctx = NULL;
rc = ksmbd_gen_sess_key(sess, ntlmv2_hash, ntlmv2_rsp);
if (rc) {
@@ -281,7 +283,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn *conn, struct ksmbd_session *sess,
if (memcmp(ntlmv2->ntlmv2_hash, ntlmv2_rsp, CIFS_HMAC_MD5_HASH_SIZE) != 0)
rc = -EINVAL;
out:
- ksmbd_release_crypto_ctx(ctx);
+ if (ctx)
+ ksmbd_release_crypto_ctx(ctx);
kfree(construct);
return rc;
}