Commit 90f7c100 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: fix compound alignment with encryption 



The encryption layer can't handle the padding iovs, so flatten the
compound request into a single buffer with required padding to prevent
the server from dropping the connection when finding unaligned
compound requests.

Fixes: bc925c12 ("smb: client: improve compound padding in encryption")
Signed-off-by: default avatarPaulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 76eeb9b8

fs/smb/client/smb2ops.c

+25 −3
Original line number Diff line number Diff line
@@ -2640,13 +2640,35 @@ smb2_set_next_command(struct cifs_tcon *tcon, struct smb_rqst *rqst) 
	}



	/* SMB headers in a compound are 8 byte aligned. */

	if (!IS_ALIGNED(len, 8)) {

	if (IS_ALIGNED(len, 8))

		goto out;



	num_padding = 8 - (len & 7);

	if (smb3_encryption_required(tcon)) {

		int i;



		/*

		 * Flatten request into a single buffer with required padding as

		 * the encryption layer can't handle the padding iovs.

		 */

		for (i = 1; i < rqst->rq_nvec; i++) {

			memcpy(rqst->rq_iov[0].iov_base +

			       rqst->rq_iov[0].iov_len,

			       rqst->rq_iov[i].iov_base,

			       rqst->rq_iov[i].iov_len);

			rqst->rq_iov[0].iov_len += rqst->rq_iov[i].iov_len;

		}

		memset(rqst->rq_iov[0].iov_base + rqst->rq_iov[0].iov_len,

		       0, num_padding);

		rqst->rq_iov[0].iov_len += num_padding;

		rqst->rq_nvec = 1;

	} else {

		rqst->rq_iov[rqst->rq_nvec].iov_base = smb2_padding;

		rqst->rq_iov[rqst->rq_nvec].iov_len = num_padding;

		rqst->rq_nvec++;

		len += num_padding;

	}

	len += num_padding;

out:

	shdr->NextCommand = cpu_to_le32(len);

}