From: Namjae Jeon linkinjeon@kernel.org
commit 7b4323373d844954bb76e0e9f39c4e5fc785fa7b upstream.
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: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ksmbd/auth.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
--- a/fs/ksmbd/auth.c +++ b/fs/ksmbd/auth.c @@ -221,22 +221,22 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn { 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); @@ -272,6 +272,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn 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) { @@ -282,7 +284,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn 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; }