From mboxrd@z Thu Jan 1 00:00:00 1970 From: dormando Subject: Re: [PATCH] ipv4: fix a race in ip4_datagram_release_cb() Date: Wed, 11 Jun 2014 00:26:23 -0700 (PDT) Message-ID: References: <1402407781.3645.426.camel@edumazet-glaptop2.roam.corp.google.com> <1402448128.3645.437.camel@edumazet-glaptop2.roam.corp.google.com> <1402449173.3645.440.camel@edumazet-glaptop2.roam.corp.google.com> <1402450009.3645.444.camel@edumazet-glaptop2.roam.corp.google.com> <1402466090.3645.456.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Alexey Preobrazhensky , Steffen Klassert , David Miller , paulmck@linux.vnet.ibm.com, netdev@vger.kernel.org, Kostya Serebryany , Dmitry Vyukov , Lars Bull , Eric Dumazet , Bruce Curtis , =?ISO-8859-2?Q?Maciej_=AFenczykowski?= , Alexei Starovoitov To: Eric Dumazet Return-path: Received: from rydia.net ([69.46.88.68]:59707 "EHLO mail.rydia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751311AbaFKH0Y (ORCPT ); Wed, 11 Jun 2014 03:26:24 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 11 Jun 2014, dormando wrote: > On Tue, 10 Jun 2014, Eric Dumazet wrote: > > > On Tue, 2014-06-10 at 21:16 -0700, dormando wrote: > > > > > Ran our udpkill util against 3.10.42 with both of your patches applied... > > > seems like it ran a bit longer than normally would with this test (15-20 > > > minutes), then died: > > > > Well, could you try a recent kernel instead ? > > > > I can see some races and fixes are probably worth it. > > > > $ git log --oneline v3.10.42..v3.15 net/ipv4/route.c > > fbdc0ad ipv4: initialise the itag variable in __mkroute_input > > 0d5edc6 ipv4, route: pass 0 instead of LOOPBACK_IFINDEX to fib_validate_source() > > aad8872 ipv4: add a sock pointer to dst->output() path. > > 9114615 ipv4: return valid RTA_IIF on ip route get > > 3ed66e9 net: replace __this_cpu_inc in route.c with raw_cpu_inc > > 0b8c7f6 ipv4: remove ip_rt_dump from route.c > > 4a4eb21 ipv4: remove ipv4_ifdown_dst from route.c > > 1e8d642 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > > a625486 ipv4: fix counter in_slow_tot > > cd0f0b9 ipv4: distinguish EHOSTUNREACH from the ENETUNREACH > > 2045cea net: remove unnecessary return's > > f87c10a ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing > > dcdfdf5 ipv4: fix race in concurrent ip_route_input_slow() > > 482fc60 ipv4: introduce new IP_MTU_DISCOVER mode IP_PMTUDISC_INTERFACE > > 0baf2b3 ipv4: shrink rt_cache_stat > > 0a7e226 ipv4: fix ineffective source address selection > > 734d272 ipv4: raise IP_MAX_MTU to theoretical limit > > ca4c3fc net: split rt_genid for ipv4 and ipv6 > > 2ffae99 ipv4: use next hop exceptions also for input routes > > fe2c633 net: Convert uses of typedef ctl_table to struct ctl_table > > 6bc19fb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > > 5aad1de ipv4: use separate genid for next hop exceptions > > f016229 ipv4: rate limit updating of next hop exceptions with same pmtu > > 387aa65 ipv4: properly refresh rtable entries on pmtu/redirect events > > > > > > Newest I can realistically roll would be 3.14.6, so I just tried > that... Without your two patches, it still dies from the UDP bug. --> Meant to say here that both *with* and *without* your two new patches it still crashes. > Unfortunately 3.14 has a few regressions.. one is some bad CPU usage i'll > have to track down, and two something about pstore is broken, so I can't > get the trace from the crash. It's compressing now and has more of the > kernel log, but it's missing the actual panic part. > > $ git log --oneline v3.14..v3.15 net/ipv4/route.c > fbdc0ad ipv4: initialise the itag variable in __mkroute_input > 0d5edc6 ipv4, route: pass 0 instead of LOOPBACK_IFINDEX to fib_validate_source() > aad8872 ipv4: add a sock pointer to dst->output() path. > 9114615 ipv4: return valid RTA_IIF on ip route get > 3ed66e9 net: replace __this_cpu_inc in route.c with raw_cpu_inc > 0b8c7f6 ipv4: remove ip_rt_dump from route.c > 4a4eb21 ipv4: remove ipv4_ifdown_dst from route.c > 1e8d642 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > 2045cea net: remove unnecessary return's > > No more obvious race fixes. I can try 3.15 fully vanilla but I'm having > doubts? > > We have a few patches on top of this, but none of them are active at the > time of my test. I've tried removing them in the past and it did nothing > as well. > > Sorry :( >