Commit 215b7f9e authored by Liang Jie's avatar Liang Jie Committed by Steve French
Browse files

smb: client: correctly handle ErrorContextData as a flexible array 



The `smb2_symlink_err_rsp` structure was previously defined with
`ErrorContextData` as a single `__u8` byte. However, the `ErrorContextData`
field is intended to be a variable-length array based on `ErrorDataLength`.
This mismatch leads to incorrect pointer arithmetic and potential memory
access issues when processing error contexts.

Updates the `ErrorContextData` field to be a flexible array
(`__u8 ErrorContextData[]`). Additionally, it modifies the corresponding
casts in the `symlink_data()` function to properly handle the flexible
array, ensuring correct memory calculations and data handling.

These changes improve the robustness of SMB2 symlink error processing.

Signed-off-by: default avatarLiang Jie <liangjie@lixiang.com>
Suggested-by: default avatarTom Talpey <tom@talpey.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 48aa9952

fs/smb/client/smb2file.c

+2 −2
Original line number Diff line number Diff line
@@ -42,14 +42,14 @@ static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov) 
		end = (struct smb2_error_context_rsp *)((u8 *)err + iov->iov_len);

		do {

			if (le32_to_cpu(p->ErrorId) == SMB2_ERROR_ID_DEFAULT) {

				sym = (struct smb2_symlink_err_rsp *)&p->ErrorContextData;

				sym = (struct smb2_symlink_err_rsp *)p->ErrorContextData;

				break;

			}

			cifs_dbg(FYI, "%s: skipping unhandled error context: 0x%x\n",

				 __func__, le32_to_cpu(p->ErrorId));



			len = ALIGN(le32_to_cpu(p->ErrorDataLength), 8);

			p = (struct smb2_error_context_rsp *)((u8 *)&p->ErrorContextData + len);

			p = (struct smb2_error_context_rsp *)(p->ErrorContextData + len);

		} while (p < end);

	} else if (le32_to_cpu(err->ByteCount) >= sizeof(*sym) &&

		   iov->iov_len >= SMB2_SYMLINK_STRUCT_SIZE) {

fs/smb/client/smb2pdu.h

+1 −1
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ struct smb2_symlink_err_rsp { 
struct smb2_error_context_rsp {

	__le32 ErrorDataLength;

	__le32 ErrorId;

	__u8  ErrorContextData; /* ErrorDataLength long array */

	__u8  ErrorContextData[] __counted_by_le(ErrorDataLength);

} __packed;



/* ErrorId values */