6.16-stable review patch. If anyone has any objections, please let me know.
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From: Paulo Alcantara pc@manguebit.org
[ Upstream commit 33cfdd726381828b9907a61c038a9f48b6690a31 ]
Some servers might enforce the SPN to be set in the target info blob (AV pairs) when sending NTLMSSP_AUTH message. In Windows Server, this could be enforced with SmbServerNameHardeningLevel set to 2.
Fix this by always appending SPN (cifs/<hostname>) to the existing list of target infos when setting up NTLMv2 response blob.
Cc: linux-cifs@vger.kernel.org Cc: David Howells dhowells@redhat.com Reported-by: Pierguido Lambri plambri@redhat.com Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifsencrypt.c | 79 ++++++++++++++++++++++++++++--------- 1 file changed, 61 insertions(+), 18 deletions(-)
diff --git a/fs/smb/client/cifsencrypt.c b/fs/smb/client/cifsencrypt.c index 6be850d2a346..3cc686246908 100644 --- a/fs/smb/client/cifsencrypt.c +++ b/fs/smb/client/cifsencrypt.c @@ -532,17 +532,67 @@ CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash, struct shash_ return rc; }
+/* + * Set up NTLMv2 response blob with SPN (cifs/<hostname>) appended to the + * existing list of AV pairs. + */ +static int set_auth_key_response(struct cifs_ses *ses) +{ + size_t baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp); + size_t len, spnlen, tilen = 0, num_avs = 2 /* SPN + EOL */; + struct TCP_Server_Info *server = ses->server; + char *spn __free(kfree) = NULL; + struct ntlmssp2_name *av; + char *rsp = NULL; + int rc; + + spnlen = strlen(server->hostname); + len = sizeof("cifs/") + spnlen; + spn = kmalloc(len, GFP_KERNEL); + if (!spn) { + rc = -ENOMEM; + goto out; + } + + spnlen = scnprintf(spn, len, "cifs/%.*s", + (int)spnlen, server->hostname); + + av_for_each_entry(ses, av) + tilen += sizeof(*av) + AV_LEN(av); + + len = baselen + tilen + spnlen * sizeof(__le16) + num_avs * sizeof(*av); + rsp = kmalloc(len, GFP_KERNEL); + if (!rsp) { + rc = -ENOMEM; + goto out; + } + + memcpy(rsp + baselen, ses->auth_key.response, tilen); + av = (void *)(rsp + baselen + tilen); + av->type = cpu_to_le16(NTLMSSP_AV_TARGET_NAME); + av->length = cpu_to_le16(spnlen * sizeof(__le16)); + cifs_strtoUTF16((__le16 *)av->data, spn, spnlen, ses->local_nls); + av = (void *)((__u8 *)av + sizeof(*av) + AV_LEN(av)); + av->type = cpu_to_le16(NTLMSSP_AV_EOL); + av->length = 0; + + rc = 0; + ses->auth_key.len = len; +out: + ses->auth_key.response = rsp; + return rc; +} + int setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp) { struct shash_desc *hmacmd5 = NULL; - int rc; - int baselen; - unsigned int tilen; + unsigned char *tiblob = NULL; /* target info blob */ struct ntlmv2_resp *ntlmv2; char ntlmv2_hash[16]; - unsigned char *tiblob = NULL; /* target info blob */ __le64 rsp_timestamp; + __u64 cc; + int rc;
if (nls_cp == NULL) { cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__); @@ -588,32 +638,25 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp) * (as Windows 7 does) */ rsp_timestamp = find_timestamp(ses); + get_random_bytes(&cc, sizeof(cc));
- baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp); - tilen = ses->auth_key.len; - tiblob = ses->auth_key.response; + cifs_server_lock(ses->server);
- ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL); - if (!ses->auth_key.response) { - rc = -ENOMEM; + tiblob = ses->auth_key.response; + rc = set_auth_key_response(ses); + if (rc) { ses->auth_key.len = 0; - goto setup_ntlmv2_rsp_ret; + goto unlock; } - ses->auth_key.len += baselen;
ntlmv2 = (struct ntlmv2_resp *) (ses->auth_key.response + CIFS_SESS_KEY_SIZE); ntlmv2->blob_signature = cpu_to_le32(0x00000101); ntlmv2->reserved = 0; ntlmv2->time = rsp_timestamp; - - get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal)); + ntlmv2->client_chal = cc; ntlmv2->reserved2 = 0;
- memcpy(ses->auth_key.response + baselen, tiblob, tilen); - - cifs_server_lock(ses->server); - rc = cifs_alloc_hash("hmac(md5)", &hmacmd5); if (rc) { cifs_dbg(VFS, "Could not allocate HMAC-MD5, rc=%d\n", rc);