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>] [day] [month] [year] [list]
Date:	Mon, 2 Jan 2012 06:09:01 -0500
From:	Jeff Layton <jlayton@...hat.com>
To:	Steve French <smfrench@...il.com>
Cc:	linux-cifs@...r.kernel.org, k.skarlatos@...il.com,
	shirishpargaonkar@...il.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] cifs: fix bad buffer length check in coalesce_t2

On Sun, 1 Jan 2012 17:35:18 -0600
Steve French <smfrench@...il.com> wrote:

> Any easy repro?

Not for me. It seems to depend on a variety of factors including the
infolevel used, the length of the filenames, and possibly their order
in the response.

> On Jan 1, 2012 9:34 AM, "Jeff Layton" <jlayton@...hat.com> wrote:
> 
> > The current check looks to see if the RFC1002 length is larger than
> > CIFSMaxBufSize, and fails if it is. The buffer is actually larger than
> > that by MAX_CIFS_HDR_SIZE.
> >
> > This bug has been around for a long time, but the fact that we used to
> > cap the clients MaxBufferSize at the same level as the server tended
> > to paper over it. Commit c974befa changed that however and caused this
> > bug to bite in more cases.
> >
> > Reported-and-Tested-by: Konstantinos Skarlatos <k.skarlatos@...il.com>
> > Signed-off-by: Jeff Layton <jlayton@...hat.com>
> > ---
> >  fs/cifs/connect.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> > index 8cd4b52..27c4f25 100644
> > --- a/fs/cifs/connect.c
> > +++ b/fs/cifs/connect.c
> > @@ -282,7 +282,7 @@ static int coalesce_t2(struct smb_hdr *psecond, struct
> > smb_hdr *pTargetSMB)
> >        byte_count = be32_to_cpu(pTargetSMB->smb_buf_length);
> >        byte_count += total_in_buf2;
> >        /* don't allow buffer to overflow */
> > -       if (byte_count > CIFSMaxBufSize)
> > +       if (byte_count > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)
> >                return -ENOBUFS;
> >        pTargetSMB->smb_buf_length = cpu_to_be32(byte_count);
> >
> > --
> > 1.7.7.4
> >
> >


-- 
Jeff Layton <jlayton@...hat.com>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists