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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 9 Oct 2020 20:34:40 -0400
From:   Willem de Bruijn <>
To:     Christian Eggers <>
Cc:     "David S . Miller" <>,
        Jakub Kicinski <>,
        Deepa Dinamani <>,
        Christoph Hellwig <>,
        Network Development <>,
        linux-kernel <>
Subject: Re: [PATCH net 2/2] socket: don't clear SOCK_TSTAMP_NEW when
 SO_TIMESTAMPNS is disabled

On Fri, Oct 9, 2020 at 6:32 AM Christian Eggers <> wrote:
> SOCK_TSTAMP_NEW (timespec64 instead of timespec) is also used for
> hardware time stamps (configured via SO_TIMESTAMPING_NEW).
> User space (ptp4l) first configures hardware time stamping via
> SO_TIMESTAMPING_NEW which sets SOCK_TSTAMP_NEW. In the next step, ptp4l
> disables SO_TIMESTAMPNS(_NEW) (software time stamps), but this must not
> switch hardware time stamps back to "32 bit mode".
> This problem happens on 32 bit platforms were the libc has already
> switched to struct timespec64 (from SO_TIMExxx_OLD to SO_TIMExxx_NEW
> socket options). ptp4l complains with "missing timestamp on transmitted
> peer delay request" because the wrong format is received (and
> discarded).
> Fixes: 887feae36aee ("socket: Add SO_TIMESTAMP[NS]_NEW")
> Fixes: 783da70e8396 ("net: add sock_enable_timestamps")
> Signed-off-by: Christian Eggers <>

Acked-by: Willem de Bruijn <>

Yes, we should just select SOCK_TSTAMP_NEW based on which of the two
syscall variants the process uses.

There is no need to reset on timestamp disable: in the common case the
selection is immaterial as timestamping is disabled.

As this commit message shows, with SO_TIMESTAMP(NS) and
SO_TIMESTAMPING that can be independently turned on and off, disabling
one can incorrectly switch modes while the other is still active.

Powered by blists - more mailing lists