FAILED: patch "[PATCH] smb: client: reject a tree connect response whose byte count" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] smb: client: reject a tree connect response whose byte count" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 65deb18359341141d37dc86fc7853511be3c87a7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090336-riverboat-makeover-fe69@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 65deb18359341141d37dc86fc7853511be3c87a7 Mon Sep 17 00:00:00 2001
From: Bryam Vargas <hexlabsecurity@proton.me>
Date: Fri, 21 Aug 2026 07:36:16 -0500
Subject: [PATCH] smb: client: reject a tree connect response whose byte count
 is too small

CIFSTCon() bounds its strnlen() over the byte area with the server's
ByteCount minus two, which for ByteCount 0 or 1 goes negative as an int
and converts to a huge size_t.  The later subtraction wraps the __u16
bytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of
up to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the
slab object, and the bytes reach userspace through tcon->nativeFileSystem
in /proc/fs/cifs/DebugData.

Reject a byte area too small for what the parser consumes.  Two bytes is
the least it can consume, and no conformant response carries fewer.  The
new trace point is the 129th smb_eio_trace entry, which __mode(byte)
cannot represent, so the attribute goes with it.

Fixes: cc20c031bb06 ("cifs: convert CIFSTCon to use new unicode helper functions")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>

diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
index 1f77512252e7..f5aad5f61dce 100644
--- a/fs/smb/client/cifssmb.c
+++ b/fs/smb/client/cifssmb.c
@@ -615,6 +615,11 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 		tcon->tid = smb_buffer_response->Tid;
 		bcc_ptr = pByteArea(smb_buffer_response);
 		bytes_left = get_bcc(smb_buffer_response);
+		if (bytes_left < 2) {
+			rc = smb_EIO2(smb_eio_trace_tcon_bcc_too_small,
+				      bytes_left, 2);
+			goto out;
+		}
 		length = strnlen(bcc_ptr, bytes_left - 2);
 		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
 			is_unicode = true;
@@ -670,6 +675,7 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 			reset_cifs_unix_caps(xid, tcon, NULL, NULL);
 		}
 	}
+out:
 	cifs_buf_release(smb_buffer);
 	return rc;
 }
diff --git a/fs/smb/client/trace.h b/fs/smb/client/trace.h
index 5b21ad3c15fb..12241abb8e2e 100644
--- a/fs/smb/client/trace.h
+++ b/fs/smb/client/trace.h
@@ -133,6 +133,7 @@
 	EM(smb_eio_trace_sym_slash,			"sym_slash") \
 	EM(smb_eio_trace_sym_target_len,		"sym_target_len") \
 	EM(smb_eio_trace_symlink_file_size,		"symlink_file_size") \
+	EM(smb_eio_trace_tcon_bcc_too_small,		"tcon_bcc_too_small") \
 	EM(smb_eio_trace_tdis_in_reconnect,		"tdis_in_reconnect") \
 	EM(smb_eio_trace_tx_chained_async,		"tx_chained_async") \
 	EM(smb_eio_trace_tx_compress_failed,		"tx_compress_failed") \
@@ -213,7 +214,7 @@
 #define EM(a, b) a,
 #define E_(a, b) a
 
-enum smb_eio_trace		{ smb_eio_traces } __mode(byte);
+enum smb_eio_trace		{ smb_eio_traces };
 enum smb3_rw_credits_trace	{ smb3_rw_credits_traces } __mode(byte);
 enum smb3_tcon_ref_trace	{ smb3_tcon_ref_traces } __mode(byte);
 

[PATCH 6.6.y 1/4] cifs: Scripted clean up fs/smb/client/fscache.h

[Sasha Levin]

From: David Howells <dhowells@redhat.com>

[ Upstream commit bc3de356aae666de5d8b5131545be87cf7754431 ]

Remove externs, correct argument names and reformat declarations.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Enzo Matsumiya <ematsumiya@suse.de>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-kernel@vger.kernel.org
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: 65deb1835934 ("smb: client: reject a tree connect response whose byte count is too small")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/smb/client/fscache.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/smb/client/fscache.h b/fs/smb/client/fscache.h
index 1f2ea9f5cc9a8..4c2e269a268ed 100644
--- a/fs/smb/client/fscache.h
+++ b/fs/smb/client/fscache.h
@@ -38,12 +38,12 @@ struct cifs_fscache_inode_coherency_data {
 /*
  * fscache.c
  */
-extern int cifs_fscache_get_super_cookie(struct cifs_tcon *);
-extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
+int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon);
+void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon);
 
-extern void cifs_fscache_get_inode_cookie(struct inode *inode);
-extern void cifs_fscache_release_inode_cookie(struct inode *);
-extern void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update);
+void cifs_fscache_get_inode_cookie(struct inode *inode);
+void cifs_fscache_release_inode_cookie(struct inode *inode);
+void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update);
 
 static inline
 void cifs_fscache_fill_coherency(struct inode *inode,
-- 
2.53.0

[PATCH 6.6.y 2/4] cifs: SMB1 split: Create smb1proto.h for SMB1 declarations

[Sasha Levin]

From: David Howells <dhowells@redhat.com>

[ Upstream commit 86c666506ea2c42649879eeac7f29e7bedef2f23 ]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Enzo Matsumiya <ematsumiya@suse.de>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-kernel@vger.kernel.org
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: 65deb1835934 ("smb: client: reject a tree connect response whose byte count is too small")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/smb/client/cifsglob.h  |  2 --
 fs/smb/client/cifsproto.h | 11 +----------
 fs/smb/client/smb1proto.h | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 12 deletions(-)
 create mode 100644 fs/smb/client/smb1proto.h

diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index a4e0618c58efc..6c4f31fec2141 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -2098,8 +2098,6 @@ extern mempool_t *cifs_mid_poolp;
 
 /* Operations for different SMB versions */
 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
-extern struct smb_version_operations smb1_operations;
-extern struct smb_version_values smb1_values;
 extern struct smb_version_operations smb20_operations;
 extern struct smb_version_values smb20_values;
 #endif /* CIFS_ALLOW_INSECURE_LEGACY */
diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index 1f37bc2923fb8..c7f8650cf2498 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -13,6 +13,7 @@
 #ifdef CONFIG_CIFS_DFS_UPCALL
 #include "dfs_cache.h"
 #endif
+#include "smb1proto.h"
 
 struct statfs;
 struct smb_rqst;
@@ -423,16 +424,6 @@ extern int CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon,
 			      struct cifsFileInfo *cfile, __u64 size,
 			      bool set_allocation);
 
-struct cifs_unix_set_info_args {
-	__u64	ctime;
-	__u64	atime;
-	__u64	mtime;
-	__u64	mode;
-	kuid_t	uid;
-	kgid_t	gid;
-	dev_t	device;
-};
-
 extern int CIFSSMBUnixSetFileInfo(const unsigned int xid,
 				  struct cifs_tcon *tcon,
 				  const struct cifs_unix_set_info_args *args,
diff --git a/fs/smb/client/smb1proto.h b/fs/smb/client/smb1proto.h
new file mode 100644
index 0000000000000..a73213f6a2aa1
--- /dev/null
+++ b/fs/smb/client/smb1proto.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+/*
+ *
+ *   Copyright (c) International Business Machines  Corp., 2002,2008
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *
+ */
+#ifndef _SMB1PROTO_H
+#define _SMB1PROTO_H
+
+struct cifs_unix_set_info_args {
+	__u64	ctime;
+	__u64	atime;
+	__u64	mtime;
+	__u64	mode;
+	kuid_t	uid;
+	kgid_t	gid;
+	dev_t	device;
+};
+
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+
+/*
+ * cifssmb.c
+ */
+
+/*
+ * smb1ops.c
+ */
+extern struct smb_version_operations smb1_operations;
+extern struct smb_version_values smb1_values;
+
+/*
+ * smb1transport.c
+ */
+
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
+#endif /* _SMB1PROTO_H */
-- 
2.53.0

[PATCH 6.6.y 3/4] cifs: SMB1 split: connect.c

[Sasha Levin]

From: David Howells <dhowells@redhat.com>

[ Upstream commit 88f7d7e32d9e086ba87c6b04a9ba57f3f41268bd ]

Split SMB1-specific connection management stuff to smb1ops.c and move
CIFSTCon() to cifssmb.c.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Enzo Matsumiya <ematsumiya@suse.de>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-kernel@vger.kernel.org
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: 65deb1835934 ("smb: client: reject a tree connect response whose byte count is too small")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/smb/client/cifsproto.h |  13 +-
 fs/smb/client/cifssmb.c   | 140 +++++++++++++++++++++
 fs/smb/client/connect.c   | 251 --------------------------------------
 fs/smb/client/smb1ops.c   | 107 ++++++++++++++++
 fs/smb/client/smb1proto.h |   5 +
 fs/smb/client/trace.h     |  36 +++++-
 6 files changed, 293 insertions(+), 259 deletions(-)

diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index c7f8650cf2498..4cab0c9524f2a 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -338,10 +338,6 @@ extern int CIFSSMBNegotiate(const unsigned int xid,
 			    struct cifs_ses *ses,
 			    struct TCP_Server_Info *server);
 
-extern int CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
-		    const char *tree, struct cifs_tcon *tcon,
-		    const struct nls_table *);
-
 extern int CIFSFindFirst(const unsigned int xid, struct cifs_tcon *tcon,
 		const char *searchName, struct cifs_sb_info *cifs_sb,
 		__u16 *searchHandle, __u16 search_flags,
@@ -384,9 +380,6 @@ extern int parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
 			       struct dfs_info3_param **target_nodes,
 			       const struct nls_table *nls_codepage, int remap,
 			       const char *searchName, bool is_unicode);
-extern void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
-				 struct cifs_sb_info *cifs_sb,
-				 struct smb3_fs_context *ctx);
 extern int CIFSSMBQFSInfo(const unsigned int xid, struct cifs_tcon *tcon,
 			struct kstatfs *FSData);
 extern int SMBOldQFSInfo(const unsigned int xid, struct cifs_tcon *tcon,
@@ -775,4 +768,10 @@ static inline void cifs_free_open_info(struct cifs_open_info_data *data)
 	memset(data, 0, sizeof(*data));
 }
 
+#define smb_EIO2(_trace, _info, _info2) \
+({ \
+	trace_smb3_eio((_trace), (_info), (_info2)); \
+	-EIO; \
+})
+
 #endif			/* _CIFSPROTO_H */
diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
index e7df15011ae33..4e3598543aef0 100644
--- a/fs/smb/client/cifssmb.c
+++ b/fs/smb/client/cifssmb.c
@@ -507,6 +507,146 @@ CIFSSMBNegotiate(const unsigned int xid,
 	return rc;
 }
 
+/*
+ * Issue a TREE_CONNECT request.
+ */
+int
+CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
+	 const char *tree, struct cifs_tcon *tcon,
+	 const struct nls_table *nls_codepage)
+{
+	struct smb_hdr *smb_buffer;
+	struct smb_hdr *smb_buffer_response;
+	TCONX_REQ *pSMB;
+	TCONX_RSP *pSMBr;
+	unsigned char *bcc_ptr;
+	int rc = 0;
+	int length;
+	__u16 bytes_left, count;
+
+	if (ses == NULL)
+		return -EIO;
+
+	smb_buffer = cifs_buf_get();
+	if (smb_buffer == NULL)
+		return -ENOMEM;
+
+	smb_buffer_response = smb_buffer;
+
+	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
+			NULL /*no tid */, 4 /*wct */);
+
+	smb_buffer->Mid = get_next_mid(ses->server);
+	smb_buffer->Uid = ses->Suid;
+	pSMB = (TCONX_REQ *) smb_buffer;
+	pSMBr = (TCONX_RSP *) smb_buffer_response;
+
+	pSMB->AndXCommand = 0xFF;
+	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
+	bcc_ptr = &pSMB->Password[0];
+
+	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
+	*bcc_ptr = 0; /* password is null byte */
+	bcc_ptr++;              /* skip password */
+	/* already aligned so no need to do it below */
+
+	if (ses->server->sign)
+		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
+
+	if (ses->capabilities & CAP_STATUS32)
+		smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
+
+	if (ses->capabilities & CAP_DFS)
+		smb_buffer->Flags2 |= SMBFLG2_DFS;
+
+	if (ses->capabilities & CAP_UNICODE) {
+		smb_buffer->Flags2 |= SMBFLG2_UNICODE;
+		length =
+		    cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
+			6 /* max utf8 char length in bytes */ *
+			(/* server len*/ + 256 /* share len */), nls_codepage);
+		bcc_ptr += 2 * length;	/* convert num 16 bit words to bytes */
+		bcc_ptr += 2;	/* skip trailing null */
+	} else {		/* ASCII */
+		strcpy(bcc_ptr, tree);
+		bcc_ptr += strlen(tree) + 1;
+	}
+	strcpy(bcc_ptr, "?????");
+	bcc_ptr += strlen("?????");
+	bcc_ptr += 1;
+	count = bcc_ptr - &pSMB->Password[0];
+	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
+	pSMB->ByteCount = cpu_to_le16(count);
+
+	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
+			 0);
+
+	/* above now done in SendReceive */
+	if (rc == 0) {
+		bool is_unicode;
+
+		tcon->tid = smb_buffer_response->Tid;
+		bcc_ptr = pByteArea(smb_buffer_response);
+		bytes_left = get_bcc(smb_buffer_response);
+		length = strnlen(bcc_ptr, bytes_left - 2);
+		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
+			is_unicode = true;
+		else
+			is_unicode = false;
+
+
+		/* skip service field (NB: this field is always ASCII) */
+		if (length == 3) {
+			if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
+			    (bcc_ptr[2] == 'C')) {
+				cifs_dbg(FYI, "IPC connection\n");
+				tcon->ipc = true;
+				tcon->pipe = true;
+			}
+		} else if (length == 2) {
+			if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
+				/* the most common case */
+				cifs_dbg(FYI, "disk share connection\n");
+			}
+		}
+		bcc_ptr += length + 1;
+		bytes_left -= (length + 1);
+		strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
+
+		/* mostly informational -- no need to fail on error here */
+		kfree(tcon->nativeFileSystem);
+		tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
+						      bytes_left, is_unicode,
+						      nls_codepage);
+
+		cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
+
+		if ((smb_buffer_response->WordCount == 3) ||
+			 (smb_buffer_response->WordCount == 7))
+			/* field is in same location */
+			tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
+		else
+			tcon->Flags = 0;
+		cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
+
+		/*
+		 * reset_cifs_unix_caps calls QFSInfo which requires
+		 * need_reconnect to be false, but we would not need to call
+		 * reset_caps if this were not a reconnect case so must check
+		 * need_reconnect flag here.  The caller will also clear
+		 * need_reconnect when tcon was successful but needed to be
+		 * cleared earlier in the case of unix extensions reconnect
+		 */
+		if (tcon->need_reconnect && tcon->unix_ext) {
+			cifs_dbg(FYI, "resetting caps for %s\n", tcon->tree_name);
+			tcon->need_reconnect = false;
+			reset_cifs_unix_caps(xid, tcon, NULL, NULL);
+		}
+	}
+	cifs_buf_release(smb_buffer);
+	return rc;
+}
+
 int
 CIFSSMBTDis(const unsigned int xid, struct cifs_tcon *tcon)
 {
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 68a000956d957..3c36859b99725 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -3265,115 +3265,6 @@ ip_connect(struct TCP_Server_Info *server)
 	return generic_ip_connect(server);
 }
 
-#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
-void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
-			  struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
-{
-	/*
-	 * If we are reconnecting then should we check to see if
-	 * any requested capabilities changed locally e.g. via
-	 * remount but we can not do much about it here
-	 * if they have (even if we could detect it by the following)
-	 * Perhaps we could add a backpointer to array of sb from tcon
-	 * or if we change to make all sb to same share the same
-	 * sb as NFS - then we only have one backpointer to sb.
-	 * What if we wanted to mount the server share twice once with
-	 * and once without posixacls or posix paths?
-	 */
-	__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
-
-	if (ctx && ctx->no_linux_ext) {
-		tcon->fsUnixInfo.Capability = 0;
-		tcon->unix_ext = 0; /* Unix Extensions disabled */
-		cifs_dbg(FYI, "Linux protocol extensions disabled\n");
-		return;
-	} else if (ctx)
-		tcon->unix_ext = 1; /* Unix Extensions supported */
-
-	if (!tcon->unix_ext) {
-		cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
-		return;
-	}
-
-	if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
-		__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
-
-		cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
-		/*
-		 * check for reconnect case in which we do not
-		 * want to change the mount behavior if we can avoid it
-		 */
-		if (ctx == NULL) {
-			/*
-			 * turn off POSIX ACL and PATHNAMES if not set
-			 * originally at mount time
-			 */
-			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
-				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
-			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
-				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
-					cifs_dbg(VFS, "POSIXPATH support change\n");
-				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
-			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
-				cifs_dbg(VFS, "possible reconnect error\n");
-				cifs_dbg(VFS, "server disabled POSIX path support\n");
-			}
-		}
-
-		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
-			cifs_dbg(VFS, "per-share encryption not supported yet\n");
-
-		cap &= CIFS_UNIX_CAP_MASK;
-		if (ctx && ctx->no_psx_acl)
-			cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
-		else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
-			cifs_dbg(FYI, "negotiated posix acl support\n");
-			if (cifs_sb)
-				cifs_sb->mnt_cifs_flags |=
-					CIFS_MOUNT_POSIXACL;
-		}
-
-		if (ctx && ctx->posix_paths == 0)
-			cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
-		else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
-			cifs_dbg(FYI, "negotiate posix pathnames\n");
-			if (cifs_sb)
-				cifs_sb->mnt_cifs_flags |=
-					CIFS_MOUNT_POSIX_PATHS;
-		}
-
-		cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
-#ifdef CONFIG_CIFS_DEBUG2
-		if (cap & CIFS_UNIX_FCNTL_CAP)
-			cifs_dbg(FYI, "FCNTL cap\n");
-		if (cap & CIFS_UNIX_EXTATTR_CAP)
-			cifs_dbg(FYI, "EXTATTR cap\n");
-		if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
-			cifs_dbg(FYI, "POSIX path cap\n");
-		if (cap & CIFS_UNIX_XATTR_CAP)
-			cifs_dbg(FYI, "XATTR cap\n");
-		if (cap & CIFS_UNIX_POSIX_ACL_CAP)
-			cifs_dbg(FYI, "POSIX ACL cap\n");
-		if (cap & CIFS_UNIX_LARGE_READ_CAP)
-			cifs_dbg(FYI, "very large read cap\n");
-		if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
-			cifs_dbg(FYI, "very large write cap\n");
-		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
-			cifs_dbg(FYI, "transport encryption cap\n");
-		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
-			cifs_dbg(FYI, "mandatory transport encryption cap\n");
-#endif /* CIFS_DEBUG2 */
-		if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
-			if (ctx == NULL)
-				cifs_dbg(FYI, "resetting capabilities failed\n");
-			else
-				cifs_dbg(VFS, "Negotiating Unix capabilities with the server failed. Consider mounting with the Unix Extensions disabled if problems are found by specifying the nounix mount option.\n");
-
-		}
-	}
-}
-#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
-
 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
 {
 	struct smb3_fs_context *ctx = cifs_sb->ctx;
@@ -3795,148 +3686,6 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 }
 #endif
 
-#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
-/*
- * Issue a TREE_CONNECT request.
- */
-int
-CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
-	 const char *tree, struct cifs_tcon *tcon,
-	 const struct nls_table *nls_codepage)
-{
-	struct smb_hdr *smb_buffer;
-	struct smb_hdr *smb_buffer_response;
-	TCONX_REQ *pSMB;
-	TCONX_RSP *pSMBr;
-	unsigned char *bcc_ptr;
-	int rc = 0;
-	int length;
-	__u16 bytes_left, count;
-
-	if (ses == NULL)
-		return -EIO;
-
-	smb_buffer = cifs_buf_get();
-	if (smb_buffer == NULL)
-		return -ENOMEM;
-
-	smb_buffer_response = smb_buffer;
-
-	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
-			NULL /*no tid */, 4 /*wct */);
-
-	smb_buffer->Mid = get_next_mid(ses->server);
-	smb_buffer->Uid = ses->Suid;
-	pSMB = (TCONX_REQ *) smb_buffer;
-	pSMBr = (TCONX_RSP *) smb_buffer_response;
-
-	pSMB->AndXCommand = 0xFF;
-	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
-	bcc_ptr = &pSMB->Password[0];
-
-	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
-	*bcc_ptr = 0; /* password is null byte */
-	bcc_ptr++;              /* skip password */
-	/* already aligned so no need to do it below */
-
-	if (ses->server->sign)
-		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
-
-	if (ses->capabilities & CAP_STATUS32)
-		smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
-
-	if (ses->capabilities & CAP_DFS)
-		smb_buffer->Flags2 |= SMBFLG2_DFS;
-
-	if (ses->capabilities & CAP_UNICODE) {
-		smb_buffer->Flags2 |= SMBFLG2_UNICODE;
-		length =
-		    cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
-			6 /* max utf8 char length in bytes */ *
-			(/* server len*/ + 256 /* share len */), nls_codepage);
-		bcc_ptr += 2 * length;	/* convert num 16 bit words to bytes */
-		bcc_ptr += 2;	/* skip trailing null */
-	} else {		/* ASCII */
-		strcpy(bcc_ptr, tree);
-		bcc_ptr += strlen(tree) + 1;
-	}
-	strcpy(bcc_ptr, "?????");
-	bcc_ptr += strlen("?????");
-	bcc_ptr += 1;
-	count = bcc_ptr - &pSMB->Password[0];
-	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
-	pSMB->ByteCount = cpu_to_le16(count);
-
-	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
-			 0);
-
-	/* above now done in SendReceive */
-	if (rc == 0) {
-		bool is_unicode;
-
-		tcon->tid = smb_buffer_response->Tid;
-		bcc_ptr = pByteArea(smb_buffer_response);
-		bytes_left = get_bcc(smb_buffer_response);
-		length = strnlen(bcc_ptr, bytes_left - 2);
-		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
-			is_unicode = true;
-		else
-			is_unicode = false;
-
-
-		/* skip service field (NB: this field is always ASCII) */
-		if (length == 3) {
-			if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
-			    (bcc_ptr[2] == 'C')) {
-				cifs_dbg(FYI, "IPC connection\n");
-				tcon->ipc = true;
-				tcon->pipe = true;
-			}
-		} else if (length == 2) {
-			if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
-				/* the most common case */
-				cifs_dbg(FYI, "disk share connection\n");
-			}
-		}
-		bcc_ptr += length + 1;
-		bytes_left -= (length + 1);
-		strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
-
-		/* mostly informational -- no need to fail on error here */
-		kfree(tcon->nativeFileSystem);
-		tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
-						      bytes_left, is_unicode,
-						      nls_codepage);
-
-		cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
-
-		if ((smb_buffer_response->WordCount == 3) ||
-			 (smb_buffer_response->WordCount == 7))
-			/* field is in same location */
-			tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
-		else
-			tcon->Flags = 0;
-		cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
-
-		/*
-		 * reset_cifs_unix_caps calls QFSInfo which requires
-		 * need_reconnect to be false, but we would not need to call
-		 * reset_caps if this were not a reconnect case so must check
-		 * need_reconnect flag here.  The caller will also clear
-		 * need_reconnect when tcon was successful but needed to be
-		 * cleared earlier in the case of unix extensions reconnect
-		 */
-		if (tcon->need_reconnect && tcon->unix_ext) {
-			cifs_dbg(FYI, "resetting caps for %s\n", tcon->tree_name);
-			tcon->need_reconnect = false;
-			reset_cifs_unix_caps(xid, tcon, NULL, NULL);
-		}
-	}
-	cifs_buf_release(smb_buffer);
-	return rc;
-}
-#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
-
 static void delayed_free(struct rcu_head *p)
 {
 	struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c
index c80b291a14a57..fc1b02986a08d 100644
--- a/fs/smb/client/smb1ops.c
+++ b/fs/smb/client/smb1ops.c
@@ -15,6 +15,113 @@
 #include "cifs_unicode.h"
 #include "fs_context.h"
 
+void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
+			  struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
+{
+	/*
+	 * If we are reconnecting then should we check to see if
+	 * any requested capabilities changed locally e.g. via
+	 * remount but we can not do much about it here
+	 * if they have (even if we could detect it by the following)
+	 * Perhaps we could add a backpointer to array of sb from tcon
+	 * or if we change to make all sb to same share the same
+	 * sb as NFS - then we only have one backpointer to sb.
+	 * What if we wanted to mount the server share twice once with
+	 * and once without posixacls or posix paths?
+	 */
+	__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+
+	if (ctx && ctx->no_linux_ext) {
+		tcon->fsUnixInfo.Capability = 0;
+		tcon->unix_ext = 0; /* Unix Extensions disabled */
+		cifs_dbg(FYI, "Linux protocol extensions disabled\n");
+		return;
+	} else if (ctx)
+		tcon->unix_ext = 1; /* Unix Extensions supported */
+
+	if (!tcon->unix_ext) {
+		cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
+		return;
+	}
+
+	if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
+		__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+
+		cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
+		/*
+		 * check for reconnect case in which we do not
+		 * want to change the mount behavior if we can avoid it
+		 */
+		if (ctx == NULL) {
+			/*
+			 * turn off POSIX ACL and PATHNAMES if not set
+			 * originally at mount time
+			 */
+			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
+				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
+			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
+				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
+					cifs_dbg(VFS, "POSIXPATH support change\n");
+				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
+			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
+				cifs_dbg(VFS, "possible reconnect error\n");
+				cifs_dbg(VFS, "server disabled POSIX path support\n");
+			}
+		}
+
+		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
+			cifs_dbg(VFS, "per-share encryption not supported yet\n");
+
+		cap &= CIFS_UNIX_CAP_MASK;
+		if (ctx && ctx->no_psx_acl)
+			cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
+		else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
+			cifs_dbg(FYI, "negotiated posix acl support\n");
+			if (cifs_sb)
+				cifs_sb->mnt_cifs_flags |=
+					CIFS_MOUNT_POSIXACL;
+		}
+
+		if (ctx && ctx->posix_paths == 0)
+			cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
+		else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
+			cifs_dbg(FYI, "negotiate posix pathnames\n");
+			if (cifs_sb)
+				cifs_sb->mnt_cifs_flags |=
+					CIFS_MOUNT_POSIX_PATHS;
+		}
+
+		cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
+#ifdef CONFIG_CIFS_DEBUG2
+		if (cap & CIFS_UNIX_FCNTL_CAP)
+			cifs_dbg(FYI, "FCNTL cap\n");
+		if (cap & CIFS_UNIX_EXTATTR_CAP)
+			cifs_dbg(FYI, "EXTATTR cap\n");
+		if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
+			cifs_dbg(FYI, "POSIX path cap\n");
+		if (cap & CIFS_UNIX_XATTR_CAP)
+			cifs_dbg(FYI, "XATTR cap\n");
+		if (cap & CIFS_UNIX_POSIX_ACL_CAP)
+			cifs_dbg(FYI, "POSIX ACL cap\n");
+		if (cap & CIFS_UNIX_LARGE_READ_CAP)
+			cifs_dbg(FYI, "very large read cap\n");
+		if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
+			cifs_dbg(FYI, "very large write cap\n");
+		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
+			cifs_dbg(FYI, "transport encryption cap\n");
+		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
+			cifs_dbg(FYI, "mandatory transport encryption cap\n");
+#endif /* CIFS_DEBUG2 */
+		if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
+			if (ctx == NULL)
+				cifs_dbg(FYI, "resetting capabilities failed\n");
+			else
+				cifs_dbg(VFS, "Negotiating Unix capabilities with the server failed. Consider mounting with the Unix Extensions disabled if problems are found by specifying the nounix mount option.\n");
+
+		}
+	}
+}
+
 /*
  * An NT cancel request header looks just like the original request except:
  *
diff --git a/fs/smb/client/smb1proto.h b/fs/smb/client/smb1proto.h
index a73213f6a2aa1..574910b5b4c8b 100644
--- a/fs/smb/client/smb1proto.h
+++ b/fs/smb/client/smb1proto.h
@@ -23,12 +23,17 @@ struct cifs_unix_set_info_args {
 /*
  * cifssmb.c
  */
+int CIFSTCon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
+	     struct cifs_tcon *tcon, const struct nls_table *nls_codepage);
 
 /*
  * smb1ops.c
  */
 extern struct smb_version_operations smb1_operations;
 extern struct smb_version_values smb1_values;
+void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
+			  struct cifs_sb_info *cifs_sb,
+			  struct smb3_fs_context *ctx);
 
 /*
  * smb1transport.c
diff --git a/fs/smb/client/trace.h b/fs/smb/client/trace.h
index 036c7966e2600..ebcc2913a879f 100644
--- a/fs/smb/client/trace.h
+++ b/fs/smb/client/trace.h
@@ -20,6 +20,18 @@
 /*
  * Specify enums for tracing information.
  */
+#define smb_eio_traces \
+	EM(smb_eio_trace_sym_slash,			"sym_slash") \
+	EM(smb_eio_trace_sym_target_len,		"sym_target_len") \
+	EM(smb_eio_trace_symlink_file_size,		"symlink_file_size") \
+	EM(smb_eio_trace_tdis_in_reconnect,		"tdis_in_reconnect") \
+	EM(smb_eio_trace_tx_chained_async,		"tx_chained_async") \
+	EM(smb_eio_trace_tx_compress_failed,		"tx_compress_failed") \
+	E_(smb_eio_trace_tx_copy_iter_to_buf,		"tx_copy_iter_to_buf")
+
+#define smb3_rw_credits_traces \
+	E_(cifs_trace_rw_credits_call_readv_adjust,	"rd-call-adj")
+
 #define smb3_tcon_ref_traces					      \
 	EM(netfs_trace_tcon_ref_dec_dfs_refer,		"DEC DfsRef") \
 	EM(netfs_trace_tcon_ref_free,			"FRE       ") \
@@ -67,7 +79,9 @@
 #define EM(a, b) a,
 #define E_(a, b) a
 
-enum smb3_tcon_ref_trace { smb3_tcon_ref_traces } __mode(byte);
+enum smb_eio_trace		{ smb_eio_traces } __mode(byte);
+enum smb3_rw_credits_trace	{ smb3_rw_credits_traces } __mode(byte);
+enum smb3_tcon_ref_trace	{ smb3_tcon_ref_traces } __mode(byte);
 
 #undef EM
 #undef E_
@@ -79,6 +93,8 @@ enum smb3_tcon_ref_trace { smb3_tcon_ref_traces } __mode(byte);
 #define EM(a, b) TRACE_DEFINE_ENUM(a);
 #define E_(a, b) TRACE_DEFINE_ENUM(a);
 
+smb_eio_traces;
+smb3_rw_credits_traces;
 smb3_tcon_ref_traces;
 
 #undef EM
@@ -1218,6 +1234,24 @@ TRACE_EVENT(smb3_tcon_ref,
 		      __entry->ref)
 	    );
 
+TRACE_EVENT(smb3_eio,
+	    TP_PROTO(enum smb_eio_trace trace, unsigned long info, unsigned long info2),
+	    TP_ARGS(trace, info, info2),
+	    TP_STRUCT__entry(
+		    __field(enum smb_eio_trace,	trace)
+		    __field(unsigned long,	info)
+		    __field(unsigned long,	info2)
+			     ),
+	    TP_fast_assign(
+		    __entry->trace	= trace;
+		    __entry->info	= info;
+		    __entry->info2	= info2;
+			   ),
+	    TP_printk("%s info=%lx,%lx",
+		      __print_symbolic(__entry->trace, smb_eio_traces),
+		      __entry->info, __entry->info2)
+	    );
+
 
 #undef EM
 #undef E_
-- 
2.53.0

[PATCH 6.6.y 4/4] smb: client: reject a tree connect response whose byte count is too small

[Sasha Levin]

From: Bryam Vargas <hexlabsecurity@proton.me>

[ Upstream commit 65deb18359341141d37dc86fc7853511be3c87a7 ]

CIFSTCon() bounds its strnlen() over the byte area with the server's
ByteCount minus two, which for ByteCount 0 or 1 goes negative as an int
and converts to a huge size_t.  The later subtraction wraps the __u16
bytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of
up to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the
slab object, and the bytes reach userspace through tcon->nativeFileSystem
in /proc/fs/cifs/DebugData.

Reject a byte area too small for what the parser consumes.  Two bytes is
the least it can consume, and no conformant response carries fewer.  The
new trace point is the 129th smb_eio_trace entry, which __mode(byte)
cannot represent, so the attribute goes with it.

Fixes: cc20c031bb06 ("cifs: convert CIFSTCon to use new unicode helper functions")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/smb/client/cifssmb.c | 6 ++++++
 fs/smb/client/trace.h   | 3 ++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
index 4e3598543aef0..cb4d8f6258837 100644
--- a/fs/smb/client/cifssmb.c
+++ b/fs/smb/client/cifssmb.c
@@ -588,6 +588,11 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 		tcon->tid = smb_buffer_response->Tid;
 		bcc_ptr = pByteArea(smb_buffer_response);
 		bytes_left = get_bcc(smb_buffer_response);
+		if (bytes_left < 2) {
+			rc = smb_EIO2(smb_eio_trace_tcon_bcc_too_small,
+				      bytes_left, 2);
+			goto out;
+		}
 		length = strnlen(bcc_ptr, bytes_left - 2);
 		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
 			is_unicode = true;
@@ -643,6 +648,7 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 			reset_cifs_unix_caps(xid, tcon, NULL, NULL);
 		}
 	}
+out:
 	cifs_buf_release(smb_buffer);
 	return rc;
 }
diff --git a/fs/smb/client/trace.h b/fs/smb/client/trace.h
index ebcc2913a879f..688bccf20ebf0 100644
--- a/fs/smb/client/trace.h
+++ b/fs/smb/client/trace.h
@@ -24,6 +24,7 @@
 	EM(smb_eio_trace_sym_slash,			"sym_slash") \
 	EM(smb_eio_trace_sym_target_len,		"sym_target_len") \
 	EM(smb_eio_trace_symlink_file_size,		"symlink_file_size") \
+	EM(smb_eio_trace_tcon_bcc_too_small,		"tcon_bcc_too_small") \
 	EM(smb_eio_trace_tdis_in_reconnect,		"tdis_in_reconnect") \
 	EM(smb_eio_trace_tx_chained_async,		"tx_chained_async") \
 	EM(smb_eio_trace_tx_compress_failed,		"tx_compress_failed") \
@@ -79,7 +80,7 @@
 #define EM(a, b) a,
 #define E_(a, b) a
 
-enum smb_eio_trace		{ smb_eio_traces } __mode(byte);
+enum smb_eio_trace		{ smb_eio_traces };
 enum smb3_rw_credits_trace	{ smb3_rw_credits_traces } __mode(byte);
 enum smb3_tcon_ref_trace	{ smb3_tcon_ref_traces } __mode(byte);
 
-- 
2.53.0