Commit 0801c137 authored by Thorsten Blum's avatar Thorsten Blum Committed by Steve French
Browse files

ksmbd: Annotate struct copychunk_ioctl_req with __counted_by_le() 



Add the __counted_by_le compiler attribute to the flexible array member
Chunks to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Change the data type of the flexible array member Chunks from __u8[] to
struct srv_copychunk[] for ChunkCount to match the number of elements in
the Chunks array. (With __u8[], each srv_copychunk would occupy 24 array
entries and the __counted_by compiler attribute wouldn't be applicable.)

Use struct_size() to calculate the size of the copychunk_ioctl_req.

Read Chunks[0] after checking that ChunkCount is not 0.

Signed-off-by: default avatarThorsten Blum <thorsten.blum@linux.dev>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 04afb0a3

fs/smb/server/smb2pdu.c

+2 −3
Original line number Diff line number Diff line
@@ -7562,7 +7562,6 @@ static int fsctl_copychunk(struct ksmbd_work *work, 
	ci_rsp->TotalBytesWritten =

		cpu_to_le32(ksmbd_server_side_copy_max_total_size());



	chunks = (struct srv_copychunk *)&ci_req->Chunks[0];

	chunk_count = le32_to_cpu(ci_req->ChunkCount);

	if (chunk_count == 0)

		goto out;
@@ -7570,12 +7569,12 @@ static int fsctl_copychunk(struct ksmbd_work *work, 


	/* verify the SRV_COPYCHUNK_COPY packet */

	if (chunk_count > ksmbd_server_side_copy_max_chunk_count() ||

	    input_count < offsetof(struct copychunk_ioctl_req, Chunks) +

	     chunk_count * sizeof(struct srv_copychunk)) {

	    input_count < struct_size(ci_req, Chunks, chunk_count)) {

		rsp->hdr.Status = STATUS_INVALID_PARAMETER;

		return -EINVAL;

	}



	chunks = &ci_req->Chunks[0];

	for (i = 0; i < chunk_count; i++) {

		if (le32_to_cpu(chunks[i].Length) == 0 ||

		    le32_to_cpu(chunks[i].Length) > ksmbd_server_side_copy_max_chunk_size())

fs/smb/server/smb2pdu.h

+7 −7
Original line number Diff line number Diff line
@@ -190,13 +190,6 @@ struct resume_key_ioctl_rsp { 
	__u8 Context[4]; /* ignored, Windows sets to 4 bytes of zero */

} __packed;



struct copychunk_ioctl_req {

	__le64 ResumeKey[3];

	__le32 ChunkCount;

	__le32 Reserved;

	__u8 Chunks[]; /* array of srv_copychunk */

} __packed;



struct srv_copychunk {

	__le64 SourceOffset;

	__le64 TargetOffset;
@@ -204,6 +197,13 @@ struct srv_copychunk { 
	__le32 Reserved;

} __packed;



struct copychunk_ioctl_req {

	__le64 ResumeKey[3];

	__le32 ChunkCount;

	__le32 Reserved;

	struct srv_copychunk Chunks[] __counted_by_le(ChunkCount);

} __packed;



struct copychunk_ioctl_rsp {

	__le32 ChunksWritten;

	__le32 ChunkBytesWritten;