Commit 5d115fa8 authored by DaeMyung Kang's avatar DaeMyung Kang Committed by Steve French
Browse files

ksmbd: fix CreateOptions sanitization clobbering the whole field 



smb2_open() attempts to clear conflicting CreateOptions bits
(FILE_SEQUENTIAL_ONLY_LE together with FILE_RANDOM_ACCESS_LE, and
FILE_NO_COMPRESSION_LE on a directory open), but uses a plain
assignment of the bitwise negation of the target flag:

	req->CreateOptions = ~(FILE_SEQUENTIAL_ONLY_LE);
	req->CreateOptions = ~(FILE_NO_COMPRESSION_LE);

This replaces the entire field with 0xFFFFFFFB / 0xFFFFFFEF rather
than clearing a single bit. With the SEQUENTIAL/RANDOM case, the
next check for FILE_OPEN_BY_FILE_ID_LE | CREATE_TREE_CONNECTION |
FILE_RESERVE_OPFILTER_LE then trivially matches and a legitimate
request is rejected with -EOPNOTSUPP. With the NO_COMPRESSION case,
every downstream test (FILE_DELETE_ON_CLOSE, etc.) operates on a
corrupted CreateOptions value.

Use &= ~FLAG to clear only the intended bit in both places.

Signed-off-by: default avatarDaeMyung Kang <charsyam@gmail.com>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 804054d1

fs/smb/server/smb2pdu.c

+2 −2
Original line number Diff line number Diff line
@@ -3057,7 +3057,7 @@ int smb2_open(struct ksmbd_work *work) 
	} else {

		if (req->CreateOptions & FILE_SEQUENTIAL_ONLY_LE &&

		    req->CreateOptions & FILE_RANDOM_ACCESS_LE)

			req->CreateOptions = ~(FILE_SEQUENTIAL_ONLY_LE);

			req->CreateOptions &= ~FILE_SEQUENTIAL_ONLY_LE;



		if (req->CreateOptions &

		    (FILE_OPEN_BY_FILE_ID_LE | CREATE_TREE_CONNECTION |
@@ -3071,7 +3071,7 @@ int smb2_open(struct ksmbd_work *work) 
				rc = -EINVAL;

				goto err_out2;

			} else if (req->CreateOptions & FILE_NO_COMPRESSION_LE) {

				req->CreateOptions = ~(FILE_NO_COMPRESSION_LE);

				req->CreateOptions &= ~FILE_NO_COMPRESSION_LE;

			}

		}

	}