I hope I look at the right patches/branches, appologies if not.
Do you have a branch where you have all these patches applied?
On Wed, Sep 22, 2021 at 12:28 PM Namjae Jeon <linkinjeon@xxxxxxxxxx> wrote:
>
> Add validation for request/response buffer size check in smb2_ioctl and
> fsctl_copychunk() take copychunk_ioctl_req pointer and the other arguments
> instead of smb2_ioctl_req structure and remove an unused smb2_ioctl_req
> argument of fsctl_validate_negotiate_info.
>
> Cc: Ronnie Sahlberg <ronniesahlberg@xxxxxxxxx>
> Cc: Ralph Böhme <slow@xxxxxxxxx>
> Cc: Steve French <smfrench@xxxxxxxxx>
> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
> ---
> v2:
> - fix warning: variable 'ret' is used uninitialized ret.
> v3:
> - fsctl_copychunk() take copychunk_ioctl_req pointer and the other arguments
> instead of smb2_ioctl_req structure.
> - remove an unused smb2_ioctl_req argument of fsctl_validate_negotiate_info.
> fs/ksmbd/smb2pdu.c | 87 ++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 68 insertions(+), 19 deletions(-)
>
> diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
> index aaf50f677194..e96491c9ab92 100644
> --- a/fs/ksmbd/smb2pdu.c
> +++ b/fs/ksmbd/smb2pdu.c
> @@ -6986,24 +6986,26 @@ int smb2_lock(struct ksmbd_work *work)
> return err;
> }
>
> -static int fsctl_copychunk(struct ksmbd_work *work, struct smb2_ioctl_req *req,
> +static int fsctl_copychunk(struct ksmbd_work *work,
> + struct copychunk_ioctl_req *ci_req,
> + unsigned int cnt_code,
> + unsigned int input_count,
> + unsigned long long volatile_id,
> + unsigned long long persistent_id,
> struct smb2_ioctl_rsp *rsp)
> {
> - struct copychunk_ioctl_req *ci_req;
> struct copychunk_ioctl_rsp *ci_rsp;
> struct ksmbd_file *src_fp = NULL, *dst_fp = NULL;
> struct srv_copychunk *chunks;
> unsigned int i, chunk_count, chunk_count_written = 0;
> unsigned int chunk_size_written = 0;
> loff_t total_size_written = 0;
> - int ret, cnt_code;
> + int ret = 0;
>
> - cnt_code = le32_to_cpu(req->CntCode);
> - ci_req = (struct copychunk_ioctl_req *)&req->Buffer[0];
> ci_rsp = (struct copychunk_ioctl_rsp *)&rsp->Buffer[0];
>
> - rsp->VolatileFileId = req->VolatileFileId;
> - rsp->PersistentFileId = req->PersistentFileId;
> + rsp->VolatileFileId = cpu_to_le64(volatile_id);
> + rsp->PersistentFileId = cpu_to_le64(persistent_id);
> ci_rsp->ChunksWritten =
> cpu_to_le32(ksmbd_server_side_copy_max_chunk_count());
> ci_rsp->ChunkBytesWritten =
> @@ -7013,12 +7015,13 @@ static int fsctl_copychunk(struct ksmbd_work *work, struct smb2_ioctl_req *req,
>
> chunks = (struct srv_copychunk *)&ci_req->Chunks[0];
> chunk_count = le32_to_cpu(ci_req->ChunkCount);
> + if (chunk_count == 0)
> + goto out;
> total_size_written = 0;
>
> /* verify the SRV_COPYCHUNK_COPY packet */
> if (chunk_count > ksmbd_server_side_copy_max_chunk_count() ||
> - le32_to_cpu(req->InputCount) <
> - offsetof(struct copychunk_ioctl_req, Chunks) +
> + input_count < offsetof(struct copychunk_ioctl_req, Chunks) +
> chunk_count * sizeof(struct srv_copychunk)) {
> rsp->hdr.Status = STATUS_INVALID_PARAMETER;
> return -EINVAL;
> @@ -7039,9 +7042,7 @@ static int fsctl_copychunk(struct ksmbd_work *work, struct smb2_ioctl_req *req,
>
> src_fp = ksmbd_lookup_foreign_fd(work,
> le64_to_cpu(ci_req->ResumeKey[0]));
> - dst_fp = ksmbd_lookup_fd_slow(work,
> - le64_to_cpu(req->VolatileFileId),
> - le64_to_cpu(req->PersistentFileId));
> + dst_fp = ksmbd_lookup_fd_slow(work, volatile_id, persistent_id);
> ret = -EINVAL;
> if (!src_fp ||
> src_fp->persistent_id != le64_to_cpu(ci_req->ResumeKey[1])) {
> @@ -7116,8 +7117,8 @@ static __be32 idev_ipv4_address(struct in_device *idev)
> }
>
> static int fsctl_query_iface_info_ioctl(struct ksmbd_conn *conn,
> - struct smb2_ioctl_req *req,
> - struct smb2_ioctl_rsp *rsp)
> + struct smb2_ioctl_rsp *rsp,
> + int out_buf_len)
> {
> struct network_interface_info_ioctl_rsp *nii_rsp = NULL;
> int nbytes = 0;
> @@ -7200,6 +7201,8 @@ static int fsctl_query_iface_info_ioctl(struct ksmbd_conn *conn,
> sockaddr_storage->addr6.ScopeId = 0;
> }
>
> + if (out_buf_len < sizeof(struct network_interface_info_ioctl_rsp))
> + break;
> nbytes += sizeof(struct network_interface_info_ioctl_rsp);
> }
> rtnl_unlock();
> @@ -7220,11 +7223,16 @@ static int fsctl_query_iface_info_ioctl(struct ksmbd_conn *conn,
>
> static int fsctl_validate_negotiate_info(struct ksmbd_conn *conn,
> struct validate_negotiate_info_req *neg_req,
> - struct validate_negotiate_info_rsp *neg_rsp)
> + struct validate_negotiate_info_rsp *neg_rsp,
> + int in_buf_len)
> {
> int ret = 0;
> int dialect;
>
> + if (in_buf_len < sizeof(struct validate_negotiate_info_req) +
> + le16_to_cpu(neg_req->DialectCount) * sizeof(__le16))
> + return -EINVAL;
> +
> dialect = ksmbd_lookup_dialect_by_id(neg_req->Dialects,
> neg_req->DialectCount);
> if (dialect == BAD_PROT_ID || dialect != conn->dialect) {
> @@ -7400,7 +7408,7 @@ int smb2_ioctl(struct ksmbd_work *work)
> struct smb2_ioctl_req *req;
> struct smb2_ioctl_rsp *rsp, *rsp_org;
> int cnt_code, nbytes = 0;
> - int out_buf_len;
> + int out_buf_len, in_buf_len;
> u64 id = KSMBD_NO_FID;
> struct ksmbd_conn *conn = work->conn;
> int ret = 0;
> @@ -7430,6 +7438,7 @@ int smb2_ioctl(struct ksmbd_work *work)
> cnt_code = le32_to_cpu(req->CntCode);
> out_buf_len = le32_to_cpu(req->MaxOutputResponse);
> out_buf_len = min(KSMBD_IPC_MAX_PAYLOAD, out_buf_len);
> + in_buf_len = le32_to_cpu(req->InputCount);
Do you check if you have these many bytes remaining in the buffer?
Also earlier in this function, where you assign req.
If this is not a component in a compound, then you assign req =
work->request_buf
which starts with 4 bytes for the length and the smb2_hdr starts at
offset 4, right?
But if the ioctl is inside a compound, you assign req = ksmbd_req_buf_next()
which just returns the offset to wherever NextCommand is?
There are two problems here.
Now req points to something where teh smb2 header starts at offset 0
instead of 4.
I unfortunately do not have any code to create Create/Ioctl/Close
compounds to test this,
but it looks like this is a problem.
The second is that there is no check I can see that we validate that
req now points to valid data,
which means that when we dereference req just a few lines later
(req->VolatileFileId)
we might read random data beyond the end of request_buf or we might oops.
The same might be an issue in other functions as well.
>
> switch (cnt_code) {
> case FSCTL_DFS_GET_REFERRALS:
> @@ -7465,9 +7474,16 @@ int smb2_ioctl(struct ksmbd_work *work)
> goto out;
> }
>
> + if (in_buf_len < sizeof(struct validate_negotiate_info_req))
> + return -EINVAL;
> +
> + if (out_buf_len < sizeof(struct validate_negotiate_info_rsp))
> + return -EINVAL;
> +
> ret = fsctl_validate_negotiate_info(conn,
> (struct validate_negotiate_info_req *)&req->Buffer[0],
> - (struct validate_negotiate_info_rsp *)&rsp->Buffer[0]);
> + (struct validate_negotiate_info_rsp *)&rsp->Buffer[0],
> + in_buf_len);
> if (ret < 0)
> goto out;
>
> @@ -7476,7 +7492,7 @@ int smb2_ioctl(struct ksmbd_work *work)
> rsp->VolatileFileId = cpu_to_le64(SMB2_NO_FID);
> break;
> case FSCTL_QUERY_NETWORK_INTERFACE_INFO:
> - nbytes = fsctl_query_iface_info_ioctl(conn, req, rsp);
> + nbytes = fsctl_query_iface_info_ioctl(conn, rsp, out_buf_len);
> if (nbytes < 0)
> goto out;
> break;
> @@ -7503,15 +7519,33 @@ int smb2_ioctl(struct ksmbd_work *work)
> goto out;
> }
>
> + if (in_buf_len < sizeof(struct copychunk_ioctl_req)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> if (out_buf_len < sizeof(struct copychunk_ioctl_rsp)) {
> ret = -EINVAL;
> goto out;
> }
>
> nbytes = sizeof(struct copychunk_ioctl_rsp);
> - fsctl_copychunk(work, req, rsp);
> + rsp->VolatileFileId = req->VolatileFileId;
> + rsp->PersistentFileId = req->PersistentFileId;
> + fsctl_copychunk(work,
> + (struct copychunk_ioctl_req *)&req->Buffer[0],
> + le32_to_cpu(req->CntCode),
> + le32_to_cpu(req->InputCount),
> + le64_to_cpu(req->VolatileFileId),
> + le64_to_cpu(req->PersistentFileId),
> + rsp);
> break;
> case FSCTL_SET_SPARSE:
> + if (in_buf_len < sizeof(struct file_sparse)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> ret = fsctl_set_sparse(work, id,
> (struct file_sparse *)&req->Buffer[0]);
> if (ret < 0)
> @@ -7530,6 +7564,11 @@ int smb2_ioctl(struct ksmbd_work *work)
> goto out;
> }
>
> + if (in_buf_len < sizeof(struct file_zero_data_information)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> zero_data =
> (struct file_zero_data_information *)&req->Buffer[0];
>
> @@ -7549,6 +7588,11 @@ int smb2_ioctl(struct ksmbd_work *work)
> break;
> }
> case FSCTL_QUERY_ALLOCATED_RANGES:
> + if (in_buf_len < sizeof(struct file_allocated_range_buffer)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> ret = fsctl_query_allocated_ranges(work, id,
> (struct file_allocated_range_buffer *)&req->Buffer[0],
> (struct file_allocated_range_buffer *)&rsp->Buffer[0],
> @@ -7589,6 +7633,11 @@ int smb2_ioctl(struct ksmbd_work *work)
> struct duplicate_extents_to_file *dup_ext;
> loff_t src_off, dst_off, length, cloned;
>
> + if (in_buf_len < sizeof(struct duplicate_extents_to_file)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> dup_ext = (struct duplicate_extents_to_file *)&req->Buffer[0];
>
> fp_in = ksmbd_lookup_fd_slow(work, dup_ext->VolatileFileHandle,
> --
> 2.25.1
>
