linux-stable/drivers/net/ppp
Christoph Schulz 3916a31927 net: ppp: don't call sk_chk_filter twice
Commit 568f194e8b ("net: ppp: use
sk_unattached_filter api") causes sk_chk_filter() to be called twice when
setting a PPP pass or active filter. This applies to both the generic PPP
subsystem implemented by drivers/net/ppp/ppp_generic.c and the ISDN PPP
subsystem implemented by drivers/isdn/i4l/isdn_ppp.c. The first call is from
within get_filter(). The second one is through the call chain

  ppp_ioctl() or isdn_ppp_ioctl()
  --> sk_unattached_filter_create()
      --> __sk_prepare_filter()
          --> sk_chk_filter()

The first call from within get_filter() should be deleted as get_filter() is
called just before calling sk_unattached_filter_create() later on, which
eventually calls sk_chk_filter() anyway.

For 3.15.x, this proposed change is a bugfix rather than a pure optimization as
in that branch, sk_chk_filter() may replace filter codes by other codes which
are not recognized when executing sk_chk_filter() a second time. So with
3.15.x, if sk_chk_filter() is called twice, the second invocation may yield
EINVAL (this depends on the filter codes found in the filter to be set, but
because the replacement is done for frequently used codes, this is almost
always the case). The net effect is that setting pass and/or active PPP filters
does not work anymore, since sk_unattached_filter_create() always returns
EINVAL due to the second call to sk_chk_filter(), regardless whether the filter
was originally sane or not.

Signed-off-by: Christoph Schulz <develop@kristov.de>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-14 16:15:12 -07:00
..
bsd_comp.c
Kconfig tty/serial patches for 3.9-rc1 2013-02-21 13:41:04 -08:00
Makefile
ppp_async.c tty: Fix recursive deadlock in tty_perform_flush() 2013-03-18 16:52:24 -07:00
ppp_deflate.c ppp: Change copyright notices from ANU to me 2012-03-04 20:41:38 -05:00
ppp_generic.c net: ppp: don't call sk_chk_filter twice 2014-07-14 16:15:12 -07:00
ppp_mppe.c drivers/net/*: Fix FSF address in file headers 2013-12-06 12:37:55 -05:00
ppp_mppe.h
ppp_synctty.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
pppoe.c net: pppoe: use correct channel MTU when using Multilink PPP 2014-07-14 14:35:46 -07:00
pppox.c ppp: Replace uses of <linux/if_ppp.h> with <linux/ppp-ioctl.h> 2012-03-04 20:41:38 -05:00
pptp.c inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00