From d68ce834f8cf6cb2e77f3331df65166b35466b53 Mon Sep 17 00:00:00 2001 From: Shyam Prasad N Date: Tue, 28 Apr 2026 21:37:47 +0530 Subject: [PATCH 1/7] cifs: abort open_cached_dir if we don't request leases It is possible that SMB2_open_init may not set lease context based on the requested oplock level. This can happen when leases have been temporarily or permanently disabled. When this happens, we will have open_cached_dir making an open without lease context and the response will anyway be rejected by open_cached_dir (thereby forcing a close to discard this open). That's unnecessary two round-trips to the server. This change adds a check before making the open request to the server to make sure that SMB2_open_init did add the expected lease context to the open in open_cached_dir. Cc: Reviewed-by: Bharath SM Signed-off-by: Shyam Prasad N Signed-off-by: Steve French --- fs/smb/client/cached_dir.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c index 02791ec3c5a1..88d5e9a32f28 100644 --- a/fs/smb/client/cached_dir.c +++ b/fs/smb/client/cached_dir.c @@ -286,6 +286,14 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, &rqst[0], &oplock, &oparms, utf16_path); if (rc) goto oshr_free; + + if (oplock != SMB2_OPLOCK_LEVEL_II) { + rc = -EINVAL; + cifs_dbg(FYI, "%s: Oplock level %d not suitable for cached directory\n", + __func__, oplock); + goto oshr_free; + } + smb2_set_next_command(tcon, &rqst[0]); memset(&qi_iov, 0, sizeof(qi_iov)); From 5e489c6c47a2ac15edbaca153b9348e42c1eacab Mon Sep 17 00:00:00 2001 From: Bjoern Doebel Date: Thu, 30 Apr 2026 08:57:17 +0000 Subject: [PATCH 2/7] smb: client: use kzalloc to zero-initialize security descriptor buffer Commit 62e7dd0a39c2d ("smb: common: change the data type of num_aces to le16") split struct smb_acl's __le32 num_aces field into __le16 num_aces and __le16 reserved. The reserved field corresponds to Sbz2 in the MS-DTYP ACL wire format, which must be zero [1]. When building an ACL descriptor in build_sec_desc(), we are using a kmalloc()'ed descriptor buffer and writing the fields explicitly using le16() writes now. This never writes to the 2 byte reserved field, leaving it as uninitialized heap data. When the reserved field happens to contain non-zero slab garbage, Samba rejects the security descriptor with "ndr_pull_security_descriptor failed: Range Error", causing chmod to fail with EINVAL. Change kmalloc() to kzalloc() to ensure the entire buffer is zero-initialized. Fixes: 62e7dd0a39c2d ("smb: common: change the data type of num_aces to le16") Cc: stable@vger.kernel.org Signed-off-by: Bjoern Doebel Assisted-by: Kiro:claude-opus-4.6 [1] https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/20233ed8-a6c6-4097-aafa-dd545ed24428 Signed-off-by: Steve French --- fs/smb/client/cifsacl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c index ec5d47779304..a2750f1e3d90 100644 --- a/fs/smb/client/cifsacl.c +++ b/fs/smb/client/cifsacl.c @@ -1732,7 +1732,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode, * descriptor parameters, and security descriptor itself */ nsecdesclen = max_t(u32, nsecdesclen, DEFAULT_SEC_DESC_LEN); - pnntsd = kmalloc(nsecdesclen, GFP_KERNEL); + pnntsd = kzalloc(nsecdesclen, GFP_KERNEL); if (!pnntsd) { kfree(pntsd); cifs_put_tlink(tlink); From 5be7a0cef3229fb3b63a07c0d289daf752545424 Mon Sep 17 00:00:00 2001 From: Piyush Sachdeva Date: Thu, 7 May 2026 22:22:13 +0530 Subject: [PATCH 3/7] smb: client: Use FullSessionKey for AES-256 encryption key derivation When Kerberos authentication is used with AES-256 encryption (AES-256-CCM or AES-256-GCM), the SMB3 encryption and decryption keys must be derived using the full session key (Session.FullSessionKey) rather than just the first 16 bytes (Session.SessionKey). Per MS-SMB2 section 3.2.5.3.1, when Connection.Dialect is "3.1.1" and Connection.CipherId is AES-256-CCM or AES-256-GCM, Session.FullSessionKey must be set to the full cryptographic key from the GSS authentication context. The encryption and decryption key derivation (SMBC2SCipherKey, SMBS2CCipherKey) must use this FullSessionKey as the KDF input. The signing key derivation continues to use Session.SessionKey (first 16 bytes) in all cases. Previously, generate_key() hardcoded SMB2_NTLMV2_SESSKEY_SIZE (16) as the HMAC-SHA256 key input length for all derivations. When Kerberos with AES-256 provides a 32-byte session key, the KDF for encryption/decryption was using only the first 16 bytes, producing keys that did not match the server's, causing mount failures with sec=krb5 and require_gcm_256=1. Add a full_key_size parameter to generate_key() and pass the appropriate size from generate_smb3signingkey(): - Signing: always SMB2_NTLMV2_SESSKEY_SIZE (16 bytes) - Encryption/Decryption: ses->auth_key.len when AES-256, otherwise 16 Also fix cifs_dump_full_key() to report the actual session key length for AES-256 instead of hardcoded CIFS_SESS_KEY_SIZE, so that userspace tools like Wireshark receive the correct key for decryption. Cc: Reviewed-by: Bharath SM Signed-off-by: Piyush Sachdeva Signed-off-by: Piyush Sachdeva Signed-off-by: Steve French --- fs/smb/client/ioctl.c | 2 +- fs/smb/client/smb2transport.c | 35 ++++++++++++++++++++++++++--------- 2 files changed, 27 insertions(+), 10 deletions(-) diff --git a/fs/smb/client/ioctl.c b/fs/smb/client/ioctl.c index 9afab3237e54..17408bb8ab65 100644 --- a/fs/smb/client/ioctl.c +++ b/fs/smb/client/ioctl.c @@ -296,7 +296,7 @@ static int cifs_dump_full_key(struct cifs_tcon *tcon, struct smb3_full_key_debug break; case SMB2_ENCRYPTION_AES256_CCM: case SMB2_ENCRYPTION_AES256_GCM: - out.session_key_length = CIFS_SESS_KEY_SIZE; + out.session_key_length = ses->auth_key.len; out.server_in_key_length = out.server_out_key_length = SMB3_GCM256_CRYPTKEY_SIZE; break; default: diff --git a/fs/smb/client/smb2transport.c b/fs/smb/client/smb2transport.c index 41009039b4cb..e8eeff9e50d6 100644 --- a/fs/smb/client/smb2transport.c +++ b/fs/smb/client/smb2transport.c @@ -251,7 +251,8 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) } static void generate_key(struct cifs_ses *ses, struct kvec label, - struct kvec context, __u8 *key, unsigned int key_size) + struct kvec context, __u8 *key, unsigned int key_size, + unsigned int full_key_size) { unsigned char zero = 0x0; __u8 i[4] = {0, 0, 0, 1}; @@ -265,7 +266,7 @@ static void generate_key(struct cifs_ses *ses, struct kvec label, memset(key, 0x0, key_size); hmac_sha256_init_usingrawkey(&hmac_ctx, ses->auth_key.response, - SMB2_NTLMV2_SESSKEY_SIZE); + full_key_size); hmac_sha256_update(&hmac_ctx, i, 4); hmac_sha256_update(&hmac_ctx, label.iov_base, label.iov_len); hmac_sha256_update(&hmac_ctx, &zero, 1); @@ -298,6 +299,7 @@ generate_smb3signingkey(struct cifs_ses *ses, struct TCP_Server_Info *server, const struct derivation_triplet *ptriplet) { + unsigned int full_key_size = SMB2_NTLMV2_SESSKEY_SIZE; bool is_binding = false; int chan_index = 0; @@ -330,12 +332,24 @@ generate_smb3signingkey(struct cifs_ses *ses, if (is_binding) { generate_key(ses, ptriplet->signing.label, ptriplet->signing.context, - ses->chans[chan_index].signkey, - SMB3_SIGN_KEY_SIZE); + ses->chans[chan_index].signkey, SMB3_SIGN_KEY_SIZE, + SMB2_NTLMV2_SESSKEY_SIZE); } else { generate_key(ses, ptriplet->signing.label, - ptriplet->signing.context, - ses->smb3signingkey, SMB3_SIGN_KEY_SIZE); + ptriplet->signing.context, ses->smb3signingkey, + SMB3_SIGN_KEY_SIZE, SMB2_NTLMV2_SESSKEY_SIZE); + + /* + * Per MS-SMB2 3.2.5.3.1, signing key always uses Session.SessionKey + * (first 16 bytes). Encryption/decryption keys use + * Session.FullSessionKey when dialect is 3.1.1 and cipher is + * AES-256-CCM or AES-256-GCM, otherwise Session.SessionKey. + */ + + if (server->dialect == SMB311_PROT_ID && + (server->cipher_type == SMB2_ENCRYPTION_AES256_CCM || + server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) + full_key_size = ses->auth_key.len; /* safe to access primary channel, since it will never go away */ spin_lock(&ses->chan_lock); @@ -345,10 +359,13 @@ generate_smb3signingkey(struct cifs_ses *ses, generate_key(ses, ptriplet->encryption.label, ptriplet->encryption.context, - ses->smb3encryptionkey, SMB3_ENC_DEC_KEY_SIZE); + ses->smb3encryptionkey, SMB3_ENC_DEC_KEY_SIZE, + full_key_size); + generate_key(ses, ptriplet->decryption.label, ptriplet->decryption.context, - ses->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE); + ses->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE, + full_key_size); } #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS @@ -361,7 +378,7 @@ generate_smb3signingkey(struct cifs_ses *ses, &ses->Suid); cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type); cifs_dbg(VFS, "Session Key %*ph\n", - SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response); + (int)ses->auth_key.len, ses->auth_key.response); cifs_dbg(VFS, "Signing Key %*ph\n", SMB3_SIGN_KEY_SIZE, ses->smb3signingkey); if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) || From 8cb6fc3231500233ddaf63cb7fd5435008d9ed5f Mon Sep 17 00:00:00 2001 From: Piyush Sachdeva Date: Thu, 7 May 2026 22:22:14 +0530 Subject: [PATCH 4/7] smb: client: Zero-pad short GSS session keys per MS-SMB2 Per MS-SMB2 section 3.2.5.3, Session.SessionKey is the first 16 bytes of the GSS cryptographic key, right-padded with zero bytes if the key is shorter than 16 bytes. SMB2_auth_kerberos() copies the GSS session key from the cifs.upcall response using kmemdup(msg->data, msg->sesskey_len, ...) and stores the GSS-reported length verbatim in ses->auth_key.len. generate_key() reads SMB2_NTLMV2_SESSKEY_SIZE bytes from this buffer when feeding the HMAC-SHA256 KDF for signing key derivation. If a GSS mechanism returns a session key shorter than 16 bytes (e.g. a deprecated single-DES Kerberos enctype with an 8-byte session key), the KDF call performs an out-of-bounds slab read and derives keys that do not match the server, which pads per the spec. Modern KDCs disable short-key enctypes by default, so this is latent rather than reachable in production, but it is still a kernel heap over-read. Allocate auth_key.response with kzalloc() at a length of max(msg->sesskey_len, SMB2_NTLMV2_SESSKEY_SIZE), copy the GSS key in, and rely on kzalloc()'s zero initialization for the spec-mandated padding. Set ses->auth_key.len to the padded length. Larger GSS keys (e.g. the 32-byte aes256-cts-hmac-sha1-96 session key) continue to be stored at their natural length, preserving the FullSessionKey path. Emit a cifs_dbg(VFS, ...) message when a short key is encountered to surface deprecated-enctype usage. NTLMv2 and NTLMSSP code paths produce a 16-byte session key by construction and are unaffected. Signed-off-by: Piyush Sachdeva Signed-off-by: Piyush Sachdeva Signed-off-by: Steve French --- fs/smb/client/smb2pdu.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index cb61051f9af3..995fcdd30681 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -1713,17 +1713,30 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data) is_binding = (ses->ses_status == SES_GOOD); spin_unlock(&ses->ses_lock); + /* + * Per MS-SMB2 3.2.5.3, Session.SessionKey is the first 16 bytes of the + * GSS cryptographic key, right-padded with zero bytes if shorter. + * Allocate at least SMB2_NTLMV2_SESSKEY_SIZE bytes (zeroed) so the KDF + * input buffer is always valid for HMAC-SHA256 even with deprecated + * Kerberos enctypes that return a short session key. + */ + if (unlikely(msg->sesskey_len < SMB2_NTLMV2_SESSKEY_SIZE)) + cifs_dbg(VFS, + "short GSS session key (%u bytes); zero-padding per MS-SMB2 3.2.5.3\n", + msg->sesskey_len); + kfree_sensitive(ses->auth_key.response); - ses->auth_key.response = kmemdup(msg->data, - msg->sesskey_len, - GFP_KERNEL); + ses->auth_key.len = max_t(unsigned int, msg->sesskey_len, + SMB2_NTLMV2_SESSKEY_SIZE); + ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL); if (!ses->auth_key.response) { cifs_dbg(VFS, "%s: can't allocate (%u bytes) memory\n", - __func__, msg->sesskey_len); + __func__, ses->auth_key.len); + ses->auth_key.len = 0; rc = -ENOMEM; goto out_put_spnego_key; } - ses->auth_key.len = msg->sesskey_len; + memcpy(ses->auth_key.response, msg->data, msg->sesskey_len); sess_data->iov[1].iov_base = msg->data + msg->sesskey_len; sess_data->iov[1].iov_len = msg->secblob_len; From d62b8d236fab503c6fec1d3e9a38bea71feaca20 Mon Sep 17 00:00:00 2001 From: Zisen Ye Date: Sat, 2 May 2026 18:48:36 +0800 Subject: [PATCH 5/7] smb/client: fix out-of-bounds read in symlink_data() Since smb2_check_message() returns success without length validation for the symlink error response, in symlink_data() it is possible for iov->iov_len to be smaller than sizeof(struct smb2_err_rsp). If the buffer only contains the base SMB2 header (64 bytes), accessing err->ErrorContextCount (at offset 66) or err->ByteCount later in symlink_data() will cause an out-of-bounds read. Link: https://lore.kernel.org/linux-cifs/297d8d9b-adf7-42fd-a1c2-5b1f230032bc@chenxiaosong.com/ Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+") Cc: Stable@vger.kernel.org Signed-off-by: Zisen Ye Reviewed-by: ChenXiaoSong Signed-off-by: Steve French --- fs/smb/client/smb2misc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/smb/client/smb2misc.c b/fs/smb/client/smb2misc.c index 973fce3c959c..2a7355ce1a07 100644 --- a/fs/smb/client/smb2misc.c +++ b/fs/smb/client/smb2misc.c @@ -241,7 +241,8 @@ smb2_check_message(char *buf, unsigned int pdu_len, unsigned int len, if (len != calc_len) { /* create failed on symlink */ if (command == SMB2_CREATE_HE && - shdr->Status == STATUS_STOPPED_ON_SYMLINK) + shdr->Status == STATUS_STOPPED_ON_SYMLINK && + len > calc_len) return 0; /* Windows 7 server returns 24 bytes more */ if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE) From 8d09328dfda089675e4c049f3f256064a1d1996b Mon Sep 17 00:00:00 2001 From: Zisen Ye Date: Wed, 6 May 2026 11:49:08 +0800 Subject: [PATCH 6/7] smb/client: fix out-of-bounds read in smb2_compound_op() If a server sends a truncated response but a large OutputBufferLength, and terminates the EA list early, check_wsl_eas() returns success without validating that the entire OutputBufferLength fits within iov_len. Then smb2_compound_op() does: memcpy(idata->wsl.eas, data[0], size[0]); Where size[0] is OutputBufferLength. If iov_len is smaller than size[0], memcpy can read beyond the end of the rsp_iov allocation and leak adjacent kernel heap memory. Link: https://lore.kernel.org/linux-cifs/d998240c-aca9-420d-9dbd-f5ba24af19e0@chenxiaosong.com/ Fixes: ea41367b2a60 ("smb: client: introduce SMB2_OP_QUERY_WSL_EA") Cc: stable@vger.kernel.org Signed-off-by: Zisen Ye Reviewed-by: ChenXiaoSong Signed-off-by: Steve French --- fs/smb/client/smb2inode.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c index 286912616c73..6c9c229b91f6 100644 --- a/fs/smb/client/smb2inode.c +++ b/fs/smb/client/smb2inode.c @@ -111,7 +111,7 @@ static int check_wsl_eas(struct kvec *rsp_iov) u32 outlen, next; u16 vlen; u8 nlen; - u8 *end; + u8 *ea_end, *iov_end; outlen = le32_to_cpu(rsp->OutputBufferLength); if (outlen < SMB2_WSL_MIN_QUERY_EA_RESP_SIZE || @@ -120,15 +120,19 @@ static int check_wsl_eas(struct kvec *rsp_iov) ea = (void *)((u8 *)rsp_iov->iov_base + le16_to_cpu(rsp->OutputBufferOffset)); - end = (u8 *)rsp_iov->iov_base + rsp_iov->iov_len; + ea_end = (u8 *)ea + outlen; + iov_end = (u8 *)rsp_iov->iov_base + rsp_iov->iov_len; + if (ea_end > iov_end) + return -EINVAL; + for (;;) { - if ((u8 *)ea > end - sizeof(*ea)) + if ((u8 *)ea > ea_end - sizeof(*ea)) return -EINVAL; nlen = ea->ea_name_length; vlen = le16_to_cpu(ea->ea_value_length); if (nlen != SMB2_WSL_XATTR_NAME_LEN || - (u8 *)ea->ea_data + nlen + 1 + vlen > end) + (u8 *)ea->ea_data + nlen + 1 + vlen > ea_end) return -EINVAL; switch (vlen) { From f98b48151cc502ada59d9778f0112d21f2586ca3 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Mon, 20 Apr 2026 10:47:47 -0400 Subject: [PATCH 7/7] smb: client: validate dacloffset before building DACL pointers parse_sec_desc(), build_sec_desc(), and the chown path in id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd before proving a DACL header fits inside the returned security descriptor. On 32-bit builds a malicious server can return dacloffset near U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip past the later pointer-based bounds checks. build_sec_desc() and id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped pointer in the chmod/chown rewrite paths. Validate dacloffset numerically before building any DACL pointer and reuse the same helper at the three DACL entry points. Fixes: bc3e9dd9d104 ("cifs: Change SIDs in ACEs while transferring file ownership.") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Michael Bommarito Signed-off-by: Steve French --- fs/smb/client/cifsacl.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c index a2750f1e3d90..786dbbc43c5b 100644 --- a/fs/smb/client/cifsacl.c +++ b/fs/smb/client/cifsacl.c @@ -1264,6 +1264,17 @@ static int parse_sid(struct smb_sid *psid, char *end_of_acl) return 0; } +static bool dacl_offset_valid(unsigned int acl_len, __u32 dacloffset) +{ + if (acl_len < sizeof(struct smb_acl)) + return false; + + if (dacloffset < sizeof(struct smb_ntsd)) + return false; + + return dacloffset <= acl_len - sizeof(struct smb_acl); +} + /* Convert CIFS ACL to POSIX form */ static int parse_sec_desc(struct cifs_sb_info *cifs_sb, @@ -1284,7 +1295,6 @@ static int parse_sec_desc(struct cifs_sb_info *cifs_sb, group_sid_ptr = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->gsidoffset)); dacloffset = le32_to_cpu(pntsd->dacloffset); - dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); cifs_dbg(NOISY, "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n", pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset), le32_to_cpu(pntsd->gsidoffset), @@ -1315,11 +1325,18 @@ static int parse_sec_desc(struct cifs_sb_info *cifs_sb, return rc; } - if (dacloffset) + if (dacloffset) { + if (!dacl_offset_valid(acl_len, dacloffset)) { + cifs_dbg(VFS, "Server returned illegal DACL offset\n"); + return -EINVAL; + } + + dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr, fattr, get_mode_from_special_sid); - else + } else { cifs_dbg(FYI, "no ACL\n"); /* BB grant all or default perms? */ + } return rc; } @@ -1342,6 +1359,11 @@ static int build_sec_desc(struct smb_ntsd *pntsd, struct smb_ntsd *pnntsd, dacloffset = le32_to_cpu(pntsd->dacloffset); if (dacloffset) { + if (!dacl_offset_valid(secdesclen, dacloffset)) { + cifs_dbg(VFS, "Server returned illegal DACL offset\n"); + return -EINVAL; + } + dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); rc = validate_dacl(dacl_ptr, end_of_acl); if (rc) @@ -1710,6 +1732,12 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode, nsecdesclen = sizeof(struct smb_ntsd) + (sizeof(struct smb_sid) * 2); dacloffset = le32_to_cpu(pntsd->dacloffset); if (dacloffset) { + if (!dacl_offset_valid(secdesclen, dacloffset)) { + cifs_dbg(VFS, "Server returned illegal DACL offset\n"); + rc = -EINVAL; + goto id_mode_to_cifs_acl_exit; + } + dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); rc = validate_dacl(dacl_ptr, (char *)pntsd + secdesclen); if (rc) { @@ -1752,6 +1780,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode, rc = ops->set_acl(pnntsd, nsecdesclen, inode, path, aclflag); cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc); } +id_mode_to_cifs_acl_exit: cifs_put_tlink(tlink); kfree(pnntsd);