On Mon, Apr 16, 2018 at 05:49:14PM -0700, Long Li wrote:
> From: Long Li <longli@xxxxxxxxxxxxx>
>
> The data buffer allocated on the stack can't be DMA'ed, and hence can't send
> through RDMA via SMB Direct.
>
> Fix this by allocating the request on the heap in smb3_validate_negotiate.
>
> Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> ---
> fs/cifs/smb2pdu.c | 38 ++++++++++++++++++++++----------------
> 1 file changed, 22 insertions(+), 16 deletions(-)
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 0f044c4..abbefe2 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
> int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
> {
> int rc = 0;
> - struct validate_negotiate_info_req vneg_inbuf;
> + struct validate_negotiate_info_req *pneg_inbuf;
> struct validate_negotiate_info_rsp *pneg_rsp = NULL;
> u32 rsplen;
> u32 inbuflen; /* max of 4 dialects */
> @@ -741,6 +741,9 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
> if (tcon->ses->server->rdma)
> return 0;
> #endif
> + pneg_inbuf = kmalloc(sizeof(*pneg_inbuf), GFP_KERNEL);
> + if (!pneg_inbuf)
> + return -ENOMEM;
>
> /* In SMB3.11 preauth integrity supersedes validate negotiate */
> if (tcon->ses->server->dialect == SMB311_PROT_ID)
> @@ -764,52 +767,53 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
> if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_NULL)
> cifs_dbg(VFS, "Unexpected null user (anonymous) auth flag sent by server\n");
>
> - vneg_inbuf.Capabilities =
> + pneg_inbuf->Capabilities =
> cpu_to_le32(tcon->ses->server->vals->req_capabilities);
> - memcpy(vneg_inbuf.Guid, tcon->ses->server->client_guid,
> + memcpy(pneg_inbuf->Guid, tcon->ses->server->client_guid,
> SMB2_CLIENT_GUID_SIZE);
>
> if (tcon->ses->sign)
> - vneg_inbuf.SecurityMode =
> + pneg_inbuf->SecurityMode =
> cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
> else if (global_secflags & CIFSSEC_MAY_SIGN)
> - vneg_inbuf.SecurityMode =
> + pneg_inbuf->SecurityMode =
> cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
> else
> - vneg_inbuf.SecurityMode = 0;
> + pneg_inbuf->SecurityMode = 0;
>
>
> if (strcmp(tcon->ses->server->vals->version_string,
> SMB3ANY_VERSION_STRING) == 0) {
> - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
> - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
> - vneg_inbuf.DialectCount = cpu_to_le16(2);
> + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
> + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(2);
> /* structure is big enough for 3 dialects, sending only 2 */
> inbuflen = sizeof(struct validate_negotiate_info_req) - 2;
> } else if (strcmp(tcon->ses->server->vals->version_string,
> SMBDEFAULT_VERSION_STRING) == 0) {
> - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> - vneg_inbuf.Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> - vneg_inbuf.DialectCount = cpu_to_le16(3);
> + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> + pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(3);
> /* structure is big enough for 3 dialects */
> inbuflen = sizeof(struct validate_negotiate_info_req);
> } else {
> /* otherwise specific dialect was requested */
> - vneg_inbuf.Dialects[0] =
> + pneg_inbuf->Dialects[0] =
> cpu_to_le16(tcon->ses->server->vals->protocol_id);
> - vneg_inbuf.DialectCount = cpu_to_le16(1);
> + pneg_inbuf->DialectCount = cpu_to_le16(1);
> /* structure is big enough for 3 dialects, sending only 1 */
> inbuflen = sizeof(struct validate_negotiate_info_req) - 4;
> }
>
> rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
> FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> - (char *)&vneg_inbuf, sizeof(struct validate_negotiate_info_req),
> + (char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
> (char **)&pneg_rsp, &rsplen);
>
> if (rc != 0) {
> cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> + kfree(pneg_inbuf);
> return -EIO;
> }
>
> @@ -838,12 +842,14 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
>
> /* validate negotiate successful */
> cifs_dbg(FYI, "validate negotiate info successful\n");
> + kfree(pneg_inbuf);
> kfree(pneg_rsp);
> return 0;
>
> vneg_out:
> cifs_dbg(VFS, "protocol revalidation - security settings mismatch\n");
> err_rsp_free:
> + kfree(pneg_inbuf);
> kfree(pneg_rsp);
> return -EIO;
> }
> --
> 2.7.4
<formletter>
This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
</formletter>
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