> -----Original Message----- > From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma- > owner@xxxxxxxxxxxxxxx] On Behalf Of Long Li > Sent: Tuesday, April 17, 2018 2:17 PM > To: Steve French <sfrench@xxxxxxxxx>; linux-cifs@xxxxxxxxxxxxxxx; samba- > technical@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > rdma@xxxxxxxxxxxxxxx > Cc: longli <longli@xxxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx > Subject: [Patch v2 2/6] cifs: Allocate validate negotiation request through > kmalloc > > 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. > > Fixes: ff1c038addc4f205d5f1ede449426c7d316c0eed "Check SMB3 dialects > against downgrade attacks" > Format is: Fixes: ff1c038addc4 ("Check SMB3 dialects against downgrade attacks") It should be right above Signed-off signature. > Changes in v2: > Removed duplicated code on freeing buffers on function exit. > (Thanks to Parav Pandit <parav@xxxxxxxxxxxx>) > > Fixed typo in the patch title. > > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > --- > fs/cifs/smb2pdu.c | 57 ++++++++++++++++++++++++++++++------------------------ > - > 1 file changed, 31 insertions(+), 26 deletions(-) > > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0f044c4..41625e4 > 100644 > --- a/fs/cifs/smb2pdu.c > +++ b/fs/cifs/smb2pdu.c > @@ -729,8 +729,8 @@ 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; > + int ret, rc = -EIO; > + 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) @@ -764,53 > +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, Please check if strncmp() should be used or not. > 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, > + ret = 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), Use sizeof(*pneg_inbuf) > (char **)&pneg_rsp, &rsplen); > > - if (rc != 0) { > - cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc); > - return -EIO; > + if (ret != 0) { if (ret) is fine. > + cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", ret); > + goto out_free_inbuf; > } > > if (rsplen != sizeof(struct validate_negotiate_info_rsp)) { @@ -820,7 if (rsplen != sizeof(*pneg_rsp)) -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
