tentatively merged this and the previous patch into for-next pending
more testing
On Thu, May 21, 2020 at 12:03 AM Ronnie Sahlberg <lsahlber@xxxxxxxxxx> wrote:
>
> Move some large data structures off the stack and into dynamically
> allocated memory in the function smb2_ioctl_query_info
>
> Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
> ---
> fs/cifs/smb2ops.c | 58 +++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 35 insertions(+), 23 deletions(-)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index f829f4165d38..fa5c79f64c0b 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -1452,6 +1452,16 @@ SMB2_request_res_key(const unsigned int xid, struct cifs_tcon *tcon,
> return rc;
> }
>
> +struct iqi_vars {
> + struct smb_rqst rqst[3];
> + struct kvec rsp_iov[3];
> + struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
> + struct kvec qi_iov[1];
> + struct kvec io_iov[SMB2_IOCTL_IOV_SIZE];
> + struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];
> + struct kvec close_iov[1];
> +};
> +
> static int
> smb2_ioctl_query_info(const unsigned int xid,
> struct cifs_tcon *tcon,
> @@ -1459,6 +1469,9 @@ smb2_ioctl_query_info(const unsigned int xid,
> __le16 *path, int is_dir,
> unsigned long p)
> {
> + struct iqi_vars *vars;
> + struct smb_rqst *rqst;
> + struct kvec *rsp_iov;
> struct cifs_ses *ses = tcon->ses;
> char __user *arg = (char __user *)p;
> struct smb_query_info qi;
> @@ -1468,45 +1481,47 @@ smb2_ioctl_query_info(const unsigned int xid,
> struct smb2_query_info_rsp *qi_rsp = NULL;
> struct smb2_ioctl_rsp *io_rsp = NULL;
> void *buffer = NULL;
> - struct smb_rqst rqst[3];
> int resp_buftype[3];
> - struct kvec rsp_iov[3];
> - struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
> struct cifs_open_parms oparms;
> u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
> struct cifs_fid fid;
> - struct kvec qi_iov[1];
> - struct kvec io_iov[SMB2_IOCTL_IOV_SIZE];
> - struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];
> - struct kvec close_iov[1];
> unsigned int size[2];
> void *data[2];
> int create_options = is_dir ? CREATE_NOT_FILE : CREATE_NOT_DIR;
>
> - memset(rqst, 0, sizeof(rqst));
> + vars = kzalloc(sizeof(*vars), GFP_ATOMIC);
> + if (vars == NULL)
> + return -ENOMEM;
> + rqst = &vars->rqst[0];
> + rsp_iov = &vars->rsp_iov[0];
> +
> resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;
> - memset(rsp_iov, 0, sizeof(rsp_iov));
>
> if (copy_from_user(&qi, arg, sizeof(struct smb_query_info)))
> - return -EFAULT;
> + goto e_fault;
>
> - if (qi.output_buffer_length > 1024)
> + if (qi.output_buffer_length > 1024) {
> + kfree(vars);
> return -EINVAL;
> + }
>
> - if (!ses || !(ses->server))
> + if (!ses || !(ses->server)) {
> + kfree(vars);
> return -EIO;
> + }
>
> if (smb3_encryption_required(tcon))
> flags |= CIFS_TRANSFORM_REQ;
>
> buffer = memdup_user(arg + sizeof(struct smb_query_info),
> qi.output_buffer_length);
> - if (IS_ERR(buffer))
> + if (IS_ERR(buffer)) {
> + kfree(vars);
> return PTR_ERR(buffer);
> + }
>
> /* Open */
> - memset(&open_iov, 0, sizeof(open_iov));
> - rqst[0].rq_iov = open_iov;
> + rqst[0].rq_iov = &vars->open_iov[0];
> rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
>
> memset(&oparms, 0, sizeof(oparms));
> @@ -1548,8 +1563,7 @@ smb2_ioctl_query_info(const unsigned int xid,
> if (!capable(CAP_SYS_ADMIN))
> rc = -EPERM;
> else {
> - memset(&io_iov, 0, sizeof(io_iov));
> - rqst[1].rq_iov = io_iov;
> + rqst[1].rq_iov = &vars->io_iov[0];
> rqst[1].rq_nvec = SMB2_IOCTL_IOV_SIZE;
>
> rc = SMB2_ioctl_init(tcon, &rqst[1],
> @@ -1565,8 +1579,7 @@ smb2_ioctl_query_info(const unsigned int xid,
> if (!capable(CAP_SYS_ADMIN))
> rc = -EPERM;
> else {
> - memset(&si_iov, 0, sizeof(si_iov));
> - rqst[1].rq_iov = si_iov;
> + rqst[1].rq_iov = &vars->si_iov[0];
> rqst[1].rq_nvec = 1;
>
> size[0] = 8;
> @@ -1579,8 +1592,7 @@ smb2_ioctl_query_info(const unsigned int xid,
> SMB2_O_INFO_FILE, 0, data, size);
> }
> } else if (qi.flags == PASSTHRU_QUERY_INFO) {
> - memset(&qi_iov, 0, sizeof(qi_iov));
> - rqst[1].rq_iov = qi_iov;
> + rqst[1].rq_iov = &vars->qi_iov[0];
> rqst[1].rq_nvec = 1;
>
> rc = SMB2_query_info_init(tcon, &rqst[1], COMPOUND_FID,
> @@ -1599,8 +1611,7 @@ smb2_ioctl_query_info(const unsigned int xid,
> smb2_set_related(&rqst[1]);
>
> /* Close */
> - memset(&close_iov, 0, sizeof(close_iov));
> - rqst[2].rq_iov = close_iov;
> + rqst[2].rq_iov = &vars->close_iov[0];
> rqst[2].rq_nvec = 1;
>
> rc = SMB2_close_init(tcon, &rqst[2], COMPOUND_FID, COMPOUND_FID, false);
> @@ -1649,6 +1660,7 @@ smb2_ioctl_query_info(const unsigned int xid,
> }
>
> iqinf_exit:
> + kfree(vars);
> kfree(buffer);
> SMB2_open_free(&rqst[0]);
> if (qi.flags & PASSTHRU_FSCTL)
> --
> 2.13.6
>
--
Thanks,
Steve
