Merge branch 'for-linus' of git://git.samba.org/sfrench/cifs-2.6

Pull CIFS fixes from Steve French:
 "Three cifs fixes, the most important fixing the problem with passing
  bogus pointers with writev (CVE-2014-0069).

  Two additional cifs fixes are still in review (including the fix for
  an append problem which Al also discovered)"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix too big maxBuf size for SMB3 mounts
  cifs: ensure that uncached writes handle unmapped areas correctly
  [CIFS] Fix cifsacl mounts over smb2 to not call cifs

10 files changed, 78 insertions, 28 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index c819b0bd491a..7ff866dbb89e 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -865,8 +865,8 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 	return rc;
 }
 
-static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
-		__u16 fid, u32 *pacllen)
+struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
+		const struct cifs_fid *cifsfid, u32 *pacllen)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	unsigned int xid;
@@ -877,7 +877,8 @@ static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
 		return ERR_CAST(tlink);
 
 	xid = get_xid();
-	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
+	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), cifsfid->netfid, &pntsd,
+				pacllen);
 	free_xid(xid);
 
 	cifs_put_tlink(tlink);
@@ -946,7 +947,7 @@ struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
 	if (!open_file)
 		return get_cifs_acl_by_path(cifs_sb, path, pacllen);
 
-	pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->fid.netfid, pacllen);
+	pntsd = get_cifs_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
 	cifsFileInfo_put(open_file);
 	return pntsd;
 }
@@ -1006,19 +1007,31 @@ out:
 /* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
 int
 cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
-		  struct inode *inode, const char *path, const __u16 *pfid)
+		  struct inode *inode, const char *path,
+		  const struct cifs_fid *pfid)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	u32 acllen = 0;
 	int rc = 0;
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+	struct cifs_tcon *tcon;
 
 	cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
 
-	if (pfid)
-		pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
-	else
-		pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	tcon = tlink_tcon(tlink);
 
+	if (pfid && (tcon->ses->server->ops->get_acl_by_fid))
+		pntsd = tcon->ses->server->ops->get_acl_by_fid(cifs_sb, pfid,
+							  &acllen);
+	else if (tcon->ses->server->ops->get_acl)
+		pntsd = tcon->ses->server->ops->get_acl(cifs_sb, inode, path,
+							&acllen);
+	else {
+		cifs_put_tlink(tlink);
+		return -EOPNOTSUPP;
+	}
 	/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
 	if (IS_ERR(pntsd)) {
 		rc = PTR_ERR(pntsd);
@@ -1030,6 +1043,8 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 			cifs_dbg(VFS, "parse sec desc failed rc = %d\n", rc);
 	}
 
+	cifs_put_tlink(tlink);
+
 	return rc;
 }
 
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 86dc28c7aa5c..cf32f0393369 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -398,6 +398,8 @@ struct smb_version_operations {
 			const struct nls_table *, int);
 	struct cifs_ntsd * (*get_acl)(struct cifs_sb_info *, struct inode *,
 			const char *, u32 *);
+	struct cifs_ntsd * (*get_acl_by_fid)(struct cifs_sb_info *,
+			const struct cifs_fid *, u32 *);
 	int (*set_acl)(struct cifs_ntsd *, __u32, struct inode *, const char *,
 			int);
 };
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index d00e09dfc452..acc4ee8ed075 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -151,7 +151,7 @@ extern struct inode *cifs_iget(struct super_block *sb,
 
 extern int cifs_get_inode_info(struct inode **inode, const char *full_path,
 			       FILE_ALL_INFO *data, struct super_block *sb,
-			       int xid, const __u16 *fid);
+			       int xid, const struct cifs_fid *fid);
 extern int cifs_get_inode_info_unix(struct inode **pinode,
 			const unsigned char *search_path,
 			struct super_block *sb, unsigned int xid);
@@ -162,11 +162,13 @@ extern int cifs_rename_pending_delete(const char *full_path,
 				      const unsigned int xid);
 extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
 			      struct cifs_fattr *fattr, struct inode *inode,
-			      const char *path, const __u16 *pfid);
+			      const char *path, const struct cifs_fid *pfid);
 extern int id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64,
 					kuid_t, kgid_t);
 extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
 					const char *, u32 *);
+extern struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *,
+						const struct cifs_fid *, u32 *);
 extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
 				const char *, int);
 
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index d3a6796caa5a..3db0c5fd9a11 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -378,7 +378,7 @@ cifs_create_get_file_info:
 					      xid);
 	else {
 		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
-					 xid, &fid->netfid);
+					 xid, fid);
 		if (newinode) {
 			if (server->ops->set_lease_key)
 				server->ops->set_lease_key(newinode, fid);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 755584684f6c..53c15074bb36 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -244,7 +244,7 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 					      xid);
 	else
 		rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
-					 xid, &fid->netfid);
+					 xid, fid);
 
 out:
 	kfree(buf);
@@ -2389,7 +2389,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
 		 unsigned long nr_segs, loff_t *poffset)
 {
 	unsigned long nr_pages, i;
-	size_t copied, len, cur_len;
+	size_t bytes, copied, len, cur_len;
 	ssize_t total_written = 0;
 	loff_t offset;
 	struct iov_iter it;
@@ -2444,14 +2444,45 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
 
 		save_len = cur_len;
 		for (i = 0; i < nr_pages; i++) {
-			copied = min_t(const size_t, cur_len, PAGE_SIZE);
+			bytes = min_t(const size_t, cur_len, PAGE_SIZE);
 			copied = iov_iter_copy_from_user(wdata->pages[i], &it,
-							 0, copied);
+							 0, bytes);
 			cur_len -= copied;
 			iov_iter_advance(&it, copied);
+			/*
+			 * If we didn't copy as much as we expected, then that
+			 * may mean we trod into an unmapped area. Stop copying
+			 * at that point. On the next pass through the big
+			 * loop, we'll likely end up getting a zero-length
+			 * write and bailing out of it.
+			 */
+			if (copied < bytes)
+				break;
 		}
 		cur_len = save_len - cur_len;
 
+		/*
+		 * If we have no data to send, then that probably means that
+		 * the copy above failed altogether. That's most likely because
+		 * the address in the iovec was bogus. Set the rc to -EFAULT,
+		 * free anything we allocated and bail out.
+		 */
+		if (!cur_len) {
+			for (i = 0; i < nr_pages; i++)
+				put_page(wdata->pages[i]);
+			kfree(wdata);
+			rc = -EFAULT;
+			break;
+		}
+
+		/*
+		 * i + 1 now represents the number of pages we actually used in
+		 * the copy phase above. Bring nr_pages down to that, and free
+		 * any pages that we didn't use.
+		 */
+		for ( ; nr_pages > i + 1; nr_pages--)
+			put_page(wdata->pages[nr_pages - 1]);
+
 		wdata->sync_mode = WB_SYNC_ALL;
 		wdata->nr_pages = nr_pages;
 		wdata->offset = (__u64)offset;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index be58b8fcdb3c..aadc2b68678b 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -677,7 +677,7 @@ cgfi_exit:
 int
 cifs_get_inode_info(struct inode **inode, const char *full_path,
 		    FILE_ALL_INFO *data, struct super_block *sb, int xid,
-		    const __u16 *fid)
+		    const struct cifs_fid *fid)
 {
 	bool validinum = false;
 	__u16 srchflgs;
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index bfd66d84831e..526fb89f9230 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -1073,6 +1073,7 @@ struct smb_version_operations smb1_operations = {
 #endif /* CIFS_XATTR */
 #ifdef CONFIG_CIFS_ACL
 	.get_acl = get_cifs_acl,
+	.get_acl_by_fid = get_cifs_acl_by_fid,
 	.set_acl = set_cifs_acl,
 #endif /* CIFS_ACL */
 };
diff --git a/fs/cifs/smb2glob.h b/fs/cifs/smb2glob.h
index c38350851b08..bc0bb9c34f72 100644
--- a/fs/cifs/smb2glob.h
+++ b/fs/cifs/smb2glob.h
@@ -57,4 +57,7 @@
 #define SMB2_CMACAES_SIZE (16)
 #define SMB3_SIGNKEY_SIZE (16)
 
+/* Maximum buffer size value we can send with 1 credit */
+#define SMB2_MAX_BUFFER_SIZE 65536
+
 #endif	/* _SMB2_GLOB_H */
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 757da3e54d3d..192f51a12cf1 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -182,11 +182,8 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
 	/* start with specified wsize, or default */
 	wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
 	wsize = min_t(unsigned int, wsize, server->max_write);
-	/*
-	 * limit write size to 2 ** 16, because we don't support multicredit
-	 * requests now.
-	 */
-	wsize = min_t(unsigned int, wsize, 2 << 15);
+	/* set it to the maximum buffer size value we can send with 1 credit */
+	wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);
 
 	return wsize;
 }
@@ -200,11 +197,8 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
 	/* start with specified rsize, or default */
 	rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
 	rsize = min_t(unsigned int, rsize, server->max_read);
-	/*
-	 * limit write size to 2 ** 16, because we don't support multicredit
-	 * requests now.
-	 */
-	rsize = min_t(unsigned int, rsize, 2 << 15);
+	/* set it to the maximum buffer size value we can send with 1 credit */
+	rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);
 
 	return rsize;
 }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a3f7a9c3cc69..860344701067 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -413,7 +413,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 
 	/* SMB2 only has an extended negflavor */
 	server->negflavor = CIFS_NEGFLAVOR_EXTENDED;
-	server->maxBuf = le32_to_cpu(rsp->MaxTransactSize);
+	/* set it to the maximum buffer size value we can send with 1 credit */
+	server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize),
+			       SMB2_MAX_BUFFER_SIZE);
 	server->max_read = le32_to_cpu(rsp->MaxReadSize);
 	server->max_write = le32_to_cpu(rsp->MaxWriteSize);
 	/* BB Do we need to validate the SecurityMode? */