linux-kernel - RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <MWHPR2101MB0729B22028B722198A51E3B3CEB70@MWHPR2101MB0729.namprd21.prod.outlook.com>
Date:   Tue, 17 Apr 2018 18:11:42 +0000
From:   Long Li <longli@...rosoft.com>
To:     Parav Pandit <parav@...lanox.com>,
        Steve French <sfrench@...ba.org>,
        "linux-cifs@...r.kernel.org" <linux-cifs@...r.kernel.org>,
        "samba-technical@...ts.samba.org" <samba-technical@...ts.samba.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-rdma@...r.kernel.org" <linux-rdma@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
Subject: RE: [PATCH 2/6] cifs: Allocate validate negoation request through
 kmalloc

> Subject: RE: [PATCH 2/6] cifs: Allocate validate negoation request through
> kmalloc
> 
> 
> 
> > -----Original Message-----
> > From: linux-rdma-owner@...r.kernel.org [mailto:linux-rdma-
> > owner@...r.kernel.org] On Behalf Of Long Li
> > Sent: Monday, April 16, 2018 7:49 PM
> > To: Steve French <sfrench@...ba.org>; linux-cifs@...r.kernel.org;
> > samba- technical@...ts.samba.org; linux-kernel@...r.kernel.org; linux-
> > rdma@...r.kernel.org; stable@...r.kernel.org
> > Cc: longli <longli@...rosoft.com>
> > Subject: [PATCH 2/6] cifs: Allocate validate negoation request through
> > kmalloc
> >
> > From: Long Li <longli@...rosoft.com>
> >
> > 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.
> >
> Please provide Fixes ("12-letters commit id") "commit string" which
> introduced this issue and it is getting fixed here, so that other can apply this
> fix to older versions.

Will do.

> 
> > Signed-off-by: Long Li <longli@...rosoft.com>
> > ---
> >  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;
> [..]
> 
> >  	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;
> Instead of duplicating code here, please jump to err_rsp_free label. Kfree()
> takes care to not panic for NULL pointer.
> Or for clarity define new label.

I will fix this.

> 
> >  	}
> >
> > @@ -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
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma"
> > in the body of a message to majordomo@...r.kernel.org More
> majordomo
> > info at
> >
> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fvger.k
> > ernel.org%2Fmajordomo-
> info.html&data=02%7C01%7Clongli%40microsoft.com%
> >
> 7Cc8c0b791819745b7403408d5a417d9d2%7C72f988bf86f141af91ab2d7cd011d
> b47%
> >
> 7C1%7C0%7C636595344704783010&sdata=99vU6g%2FE5b8TG8Dn2MngmNw
> pP5MghgdoV
> > hBf0sak%2B0w%3D&reserved=0