ksmbd: handle set/get info file for streamed file

The bug only appears when:
 - windows 11 copies a file that has an alternate data stream
 - streams_xattr is enabled on the share configuration.

Microsoft Edge adds a ZoneIdentifier data stream containing the URL
for files it downloads.

Another way to create a test file:
 - open cmd.exe
 - echo "hello from default data stream" > hello.txt
 - echo "hello again from ads" > hello.txt:ads.txt

If you open the file using notepad, we'll see the first message.
If you run "notepad hello.txt:ads.txt" in cmd.exe, we should see
the second message.

dir /s /r should least all streams for the file.

The truncation happens because the windows 11 client sends
a SetInfo/EndOfFile message on the ADS, but it is instead applied
on the main file, because we don't check fp->stream.

When receiving set/get info file for a stream file, Change to process
requests using stream position and size.
Truncate is unnecessary for stream files, so we skip
set_file_allocation_info and set_end_of_file_info operations.

Reported-by: Marios Makassikis <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: namjaejeon

fs/smb/server/smb2pdu.c

@@ -4872,8 +4872,13 @@ static int get_file_standard_info(struct smb2_query_info_rsp *rsp,
 	sinfo = (struct smb2_file_standard_info *)rsp->Buffer;
 	delete_pending = ksmbd_inode_pending_delete(fp);
 
-	sinfo->AllocationSize = cpu_to_le64(stat.blocks << 9);
-	sinfo->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+	if (ksmbd_stream_fd(fp) == false) {
+		sinfo->AllocationSize = cpu_to_le64(stat.blocks << 9);
+		sinfo->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+	} else {
+		sinfo->AllocationSize = cpu_to_le64(fp->stream.size);
+		sinfo->EndOfFile = cpu_to_le64(fp->stream.size);
+	}
 	sinfo->NumberOfLinks = cpu_to_le32(get_nlink(&stat) - delete_pending);
 	sinfo->DeletePending = delete_pending;
 	sinfo->Directory = S_ISDIR(stat.mode) ? 1 : 0;
@@ -4936,9 +4941,14 @@ static int get_file_all_info(struct ksmbd_work *work,
 	file_info->ChangeTime = cpu_to_le64(time);
 	file_info->Attributes = fp->f_ci->m_fattr;
 	file_info->Pad1 = 0;
-	file_info->AllocationSize =
-		cpu_to_le64(stat.blocks << 9);
-	file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+	if (ksmbd_stream_fd(fp) == false) {
+		file_info->AllocationSize =
+			cpu_to_le64(stat.blocks << 9);
+		file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+	} else {
+		file_info->AllocationSize = cpu_to_le64(fp->stream.size);
+		file_info->EndOfFile = cpu_to_le64(fp->stream.size);
+	}
 	file_info->NumberOfLinks =
 			cpu_to_le32(get_nlink(&stat) - delete_pending);
 	file_info->DeletePending = delete_pending;
@@ -4947,7 +4957,10 @@ static int get_file_all_info(struct ksmbd_work *work,
 	file_info->IndexNumber = cpu_to_le64(stat.ino);
 	file_info->EASize = 0;
 	file_info->AccessFlags = fp->daccess;
-	file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+	if (ksmbd_stream_fd(fp) == false)
+		file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+	else
+		file_info->CurrentByteOffset = cpu_to_le64(fp->stream.pos);
 	file_info->Mode = fp->coption;
 	file_info->AlignmentRequirement = 0;
 	conv_len = smbConvertToUTF16((__le16 *)file_info->FileName, filename,
@@ -5135,8 +5148,13 @@ static int get_file_network_open_info(struct smb2_query_info_rsp *rsp,
 	time = ksmbd_UnixTimeToNT(stat.ctime);
 	file_info->ChangeTime = cpu_to_le64(time);
 	file_info->Attributes = fp->f_ci->m_fattr;
-	file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
-	file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+	if (ksmbd_stream_fd(fp) == false) {
+		file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
+		file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+	} else {
+		file_info->AllocationSize = cpu_to_le64(fp->stream.size);
+		file_info->EndOfFile = cpu_to_le64(fp->stream.size);
+	}
 	file_info->Reserved = cpu_to_le32(0);
 	rsp->OutputBufferLength =
 		cpu_to_le32(sizeof(struct smb2_file_ntwrk_info));
@@ -5159,7 +5177,11 @@ static void get_file_position_info(struct smb2_query_info_rsp *rsp,
 	struct smb2_file_pos_info *file_info;
 
 	file_info = (struct smb2_file_pos_info *)rsp->Buffer;
-	file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+	if (ksmbd_stream_fd(fp) == false)
+		file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+	else
+		file_info->CurrentByteOffset = cpu_to_le64(fp->stream.pos);
+
 	rsp->OutputBufferLength =
 		cpu_to_le32(sizeof(struct smb2_file_pos_info));
 }
@@ -5248,8 +5270,13 @@ static int find_file_posix_info(struct smb2_query_info_rsp *rsp,
 	file_info->ChangeTime = cpu_to_le64(time);
 	file_info->DosAttributes = fp->f_ci->m_fattr;
 	file_info->Inode = cpu_to_le64(stat.ino);
-	file_info->EndOfFile = cpu_to_le64(stat.size);
-	file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
+	if (ksmbd_stream_fd(fp) == false) {
+		file_info->EndOfFile = cpu_to_le64(stat.size);
+		file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
+	} else {
+		file_info->EndOfFile = cpu_to_le64(fp->stream.size);
+		file_info->AllocationSize = cpu_to_le64(fp->stream.size);
+	}
 	file_info->HardLinks = cpu_to_le32(stat.nlink);
 	file_info->Mode = cpu_to_le32(stat.mode & 0777);
 	switch (stat.mode & S_IFMT) {
@@ -6191,6 +6218,9 @@ static int set_file_allocation_info(struct ksmbd_work *work,
 	if (!(fp->daccess & FILE_WRITE_DATA_LE))
 		return -EACCES;
 
+	if (ksmbd_stream_fd(fp) == true)
+		return 0;
+
 	rc = vfs_getattr(&fp->filp->f_path, &stat, STATX_BASIC_STATS,
 			 AT_STATX_SYNC_AS_STAT);
 	if (rc)
@@ -6249,7 +6279,8 @@ static int set_end_of_file_info(struct ksmbd_work *work, struct ksmbd_file *fp,
 	 * truncate of some filesystem like FAT32 fill zero data in
 	 * truncated range.
 	 */
-	if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC) {
+	if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC &&
+	    ksmbd_stream_fd(fp) == false) {
 		ksmbd_debug(SMB, "truncated to newsize %lld\n", newsize);
 		rc = ksmbd_vfs_truncate(work, fp, newsize);
 		if (rc) {
@@ -6322,7 +6353,13 @@ static int set_file_position_info(struct ksmbd_file *fp,
 		return -EINVAL;
 	}
 
-	fp->filp->f_pos = current_byte_offset;
+	if (ksmbd_stream_fd(fp) == false)
+		fp->filp->f_pos = current_byte_offset;
+	else {
+		if (current_byte_offset > XATTR_SIZE_MAX)
+			current_byte_offset = XATTR_SIZE_MAX;
+		fp->stream.pos = current_byte_offset;
+	}
 	return 0;
 }
 

fs/smb/server/vfs.c

@@ -293,6 +293,7 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos,
 
 	if (v_len - *pos < count)
 		count = v_len - *pos;
+	fp->stream.pos = v_len;
 
 	memcpy(buf, &stream_buf[*pos], count);
 
@@ -456,8 +457,8 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
 				 true);
 	if (err < 0)
 		goto out;
-
-	fp->filp->f_pos = *pos;
+	else
+		fp->stream.pos = size;
 	err = 0;
 out:
 	kvfree(stream_buf);

fs/smb/server/vfs_cache.h

@@ -44,6 +44,7 @@ struct ksmbd_lock {
 struct stream {
 	char *name;
 	ssize_t size;
+	loff_t pos;
 };
 
 struct ksmbd_inode {