[SCM] Samba Shared Repository - branch master updated

Andreas Schneider asn at samba.org
Thu Nov 14 01:51:00 MST 2013


On Friday 08 November 2013 23:45:08 Stefan  Metzmacher wrote:
> > commit 12a2230581b3ff5c7a29819532652d7ddfe61521
> > Author: Andreas Schneider <asn at samba.org>
> > Date:   Fri Nov 8 16:14:35 2013 +0100
> > 
> >     s4-smb_server: Fix a use after free.
> >     
> >     If we haven't allocated the smbsrv_session then we should not free it.
> >     
> >     Signed-off-by: Andreas Schneider <asn at samba.org>
> >     Reviewed-by: Jeremy Allison <jra at samba.org>
> > 
> > diff --git a/source4/smb_server/smb/sesssetup.c
> > b/source4/smb_server/smb/sesssetup.c index b26c128..4ebc0c4 100644
> > --- a/source4/smb_server/smb/sesssetup.c
> > +++ b/source4/smb_server/smb/sesssetup.c
> > @@ -415,6 +415,7 @@ static void sesssetup_spnego(struct smbsrv_request
> > *req, union smb_sesssetup *se> 
> >  {
> >  
> >  	NTSTATUS status;
> >  	struct smbsrv_session *smb_sess = NULL;
> > 
> > +	bool is_smb_sess_new = false;
> > 
> >  	struct sesssetup_spnego_state *s = NULL;
> >  	uint16_t vuid;
> >  	struct tevent_req *subreq;
> > 
> > @@ -465,6 +466,7 @@ static void sesssetup_spnego(struct smbsrv_request
> > *req, union smb_sesssetup *se> 
> >  			status = NT_STATUS_INSUFFICIENT_RESOURCES;
> >  			goto failed;
> >  		
> >  		}
> > 
> > +		is_smb_sess_new = true;
> > 
> >  	} else {
> >  	
> >  		smb_sess = smbsrv_session_find_sesssetup(req->smb_conn, vuid);
> >  	
> >  	}
> > 
> > @@ -510,7 +512,9 @@ static void sesssetup_spnego(struct smbsrv_request
> > *req, union smb_sesssetup *se> 
> >  nomem:
> >  	status = NT_STATUS_NO_MEMORY;
> >  
> >  failed:
> > -	talloc_free(smb_sess);
> > +	if (is_smb_sess_new) {
> > +		talloc_free(smb_sess);
> > +	}
> > 
> >  	status = nt_status_squash(status);
> >  	smbsrv_sesssetup_backend_send(req, sess, status);
> 
> I think we need to talloc_steal(req, smb_sess) here.
> This is similar to
> https://git.samba.org/?p=samba.git;a=commitdiff;h=25494628a2e977568de0f63460
> 2ebe893d0a5b88

I don't think so. We just allocated the smb_sess structure here and it is not 
set or attached to anything yet, so we can free it.


	-- andreas

-- 
Andreas Schneider                   GPG-ID: CC014E3D
Samba Team                             asn at samba.org
www.samba.org



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