From owner-freebsd-net@freebsd.org Sat Oct 31 13:46:04 2015 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DD84CA220E2; Sat, 31 Oct 2015 13:46:04 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-io0-x22d.google.com (mail-io0-x22d.google.com [IPv6:2607:f8b0:4001:c06::22d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A7EF71FB4; Sat, 31 Oct 2015 13:46:04 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by iodd200 with SMTP id d200so105638506iod.0; Sat, 31 Oct 2015 06:46:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=MW2WjyAiM66g+7je4Xog+4jjzEc974CcfmJeSeeF7DU=; b=qEznoCISUWZbxQC2kbIfzk2dgRk01JVND+MIplTcf13LxOpbytaEEiW5cJOXgDqqLa 9WEbYpIN7AI2Fuvs9QVKfYD6dA1/+rnPAXUOASF1fC0QIbvMbVrrA9svohGKmqhpouyP BChKAQ/oidWw51PoK9MmfRpWLoKSf9rO7uWijcBJO+qtpVnpnF6z7gbaJ47FqkSwYu6J e7qfZFHad8YWficYk5AvYhHTt0hCv7xzZgDhyWARJ57Im17nsPcC9LIHAEGWFfHTvlWs c4JjYM/G70RKvQpGMi31tUV0JC5AI9KuEw5aoVLvbz0D2/3QYRPMfItJ2v9MOPufd1wV hK7Q== MIME-Version: 1.0 X-Received: by 10.107.152.2 with SMTP id a2mr14329731ioe.123.1446299163802; Sat, 31 Oct 2015 06:46:03 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.36.46.66 with HTTP; Sat, 31 Oct 2015 06:46:03 -0700 (PDT) In-Reply-To: <2739461446298483@web2h.yandex.ru> References: <2739461446298483@web2h.yandex.ru> Date: Sat, 31 Oct 2015 09:46:03 -0400 X-Google-Sender-Auth: thS5hslgLf2fJ2EQntXQd3THCDc Message-ID: Subject: Re: panic in arptimer in r289937 From: Adrian Chadd To: "Alexander V. Chernikov" Cc: freebsd-current , FreeBSD Net Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 31 Oct 2015 13:46:05 -0000 On 31 October 2015 at 09:34, Alexander V. Chernikov wrote: > > > 31.10.2015, 05:32, "Adrian Chadd" : >> Hiya, >> >> Here's a panic from arptimer: > Hi Adrian, > > As far as I see, line 205 in if_ether.c is IF_AFDATA_LOCK(ifp) which happ= ens after LLE_WUNLOCK(). > So, it looks like (pre-cached) ifp had been freed before locking ifdata. > Do you have any more details on that? (e.g. was some interface detached a= t that moment, is it reproducible, etc..) > > From a quick glance, potential use-after-free has been possible for quite= a long time, but I wonder why it hasn't been observed before. > Probably lltable_free() changes might have triggered that. > > I'll take a deeper look on that and reply. Hiya! Thanks for your quick response. I mean, I use wifi, and ARPs can get lost / transmit can get delayed / etc. I'm also testing through a MIPS CPU based bridge, so I'm also not bridging at line rate. (The above is from one of the x86 laptops doing the traffic test.) These are both reasons why I may be poking at a path that you don't normally see. :) I appreciate you taking a very quick look at this! Thanks, -adrian > >> >> (kgdb) bt >> #0 doadump (textdump=3D0) at pcpu.h:221 >> #1 0xffffffff803666b6 in db_fncall (dummy1=3D, >> dummy2=3D, dummy3=3D, >> dummy4=3D) at >> /usr/home/adrian/work/freebsd/head/src/sys/ddb/db_command.c:568 >> #2 0xffffffff8036614e in db_command (cmd_table=3D0x0) at >> /usr/home/adrian/work/freebsd/head/src/sys/ddb/db_command.c:440 >> #3 0xffffffff80365ee4 in db_command_loop () at >> /usr/home/adrian/work/freebsd/head/src/sys/ddb/db_command.c:493 >> #4 0xffffffff8036897b in db_trap (type=3D, code=3D0= ) >> at /usr/home/adrian/work/freebsd/head/src/sys/ddb/db_main.c:251 >> #5 0xffffffff8096c0f3 in kdb_trap (type=3D9, code=3D0, tf=3D> optimized out>) at >> /usr/home/adrian/work/freebsd/head/src/sys/kern/subr_kdb.c:654 >> #6 0xffffffff80d34c81 in trap_fatal (frame=3D0xfffffe022815d7a0, >> eva=3D) at >> /usr/home/adrian/work/freebsd/head/src/sys/amd64/amd64/trap.c:829 >> #7 0xffffffff80d34951 in trap (frame=3D) at >> /usr/home/adrian/work/freebsd/head/src/sys/amd64/amd64/trap.c:203 >> #8 0xffffffff80d149f7 in calltrap () at >> /usr/home/adrian/work/freebsd/head/src/sys/amd64/amd64/exception.S:234 >> #9 0xffffffff8092c3fb in _rw_wlock_cookie (c=3D0xdeadc0dedeadc2de, >> file=3D0xffffffff81211b1f >> "/usr/home/adrian/work/freebsd/head/src/sys/netinet/if_ether.c", >> line=3D205) >> at /usr/home/adrian/work/freebsd/head/src/sys/kern/kern_rwlock.c:261 >> #10 0xffffffff80a2487f in arptimer (arg=3D0xfffff8005ecc4000) at >> /usr/home/adrian/work/freebsd/head/src/sys/netinet/if_ether.c:205 >> #11 0xffffffff80944c24 in softclock_call_cc (c=3D0xfffff8005ecc40a8, >> cc=3D0xffffffff81b2d480, direct=3D0) at >> /usr/home/adrian/work/freebsd/head/src/sys/kern/kern_timeout.c:722 >> #12 0xffffffff80944f87 in softclock (arg=3D) at >> /usr/home/adrian/work/freebsd/head/src/sys/kern/kern_timeout.c:851 >> #13 0xffffffff808f7eb6 in intr_event_execute_handlers (p=3D> optimized out>, ie=3D0xfffff800035a6600) at >> /usr/home/adrian/work/freebsd/head/src/sys/kern/kern_intr.c:1262 >> #14 0xffffffff808f8546 in ithread_loop (arg=3D0xfffff800032c47c0) at >> /usr/home/adrian/work/freebsd/head/src/sys/kern/kern_intr.c:1275 >> #15 0xffffffff808f57a4 in fork_exit (callout=3D0xffffffff808f84a0 >> , arg=3D0xfffff800032c47c0, frame=3D0xfffffe022815dac0) at >> /usr/home/adrian/work/freebsd/head/src/sys/kern/kern_fork.c:1011 >> #16 0xffffffff80d14f2e in fork_trampoline () at >> /usr/home/adrian/work/freebsd/head/src/sys/amd64/amd64/exception.S:609 >> #17 0x0000000000000000 in ?? () >> Current language: auto; currently minimal >> >> (kgdb) print *(struct llentry *)c_arg >> $2 =3D {lle_next =3D {le_next =3D 0x0, le_prev =3D 0xfffff8005e867dc8}, >> r_l3addr =3D {addr4 =3D {s_addr =3D 16782508}, addr6 =3D {__u6_addr =3D >> {__u6_addr8 =3D 0xfffff8005ecc4010 "=EF=BF=BD\024", __u6_addr16 =3D >> 0xfffff8005ecc4010, >> __u6_addr32 =3D 0xfffff8005ecc4010}}}, ll_addr =3D {mac_aligned = =3D >> 110869256150596, mac16 =3D 0xfffff8005ecc4020, mac8 =3D 0xfffff8005ecc40= 20 >> "D\036=EF=BF=BD=EF=BF=BD=EF=BF=BDd"}, spare0 =3D 0, spare1 =3D 0, lle_tb= l =3D 0xfffff8005e867e00, >> lle_head =3D 0xfffff8005e867dc8, lle_free =3D 0xffffffff80a2c5d0 >> , la_hold =3D 0x0, la_numheld =3D 0, la_expire = =3D >> 2110, la_flags =3D 1, la_asked =3D 0, la_preempt =3D 5, ln_state =3D 0, >> ln_router =3D 0, ln_ntick =3D 0, >> lle_refcnt =3D 1, lle_chain =3D {le_next =3D 0x0, le_prev =3D 0x0}, >> lle_timer =3D {c_links =3D {le =3D {le_next =3D 0x0, le_prev =3D >> 0xffffffff81b2d588}, sle =3D {sle_next =3D 0x0}, tqe =3D {tqe_next =3D 0= x0, >> tqe_prev =3D 0xffffffff81b2d588}}, >> c_time =3D 9066299815445, c_precision =3D 322122525000, c_arg =3D >> 0xfffff8005ecc4000, c_func =3D 0xffffffff80a246e0 , c_lock =3D >> 0x0, c_flags =3D 0, c_iflags =3D 144, c_cpu =3D 0}, lle_lock =3D {lock_o= bject >> =3D { >> lo_name =3D 0xffffffff8120fbce "lle", lo_flags =3D 90374144, lo_da= ta >> =3D 0, lo_witness =3D 0xfffffe0000b53c80}, rw_lock =3D 1}} >> >> .. >> >> (kgdb) print *((struct llentry *)c_arg)->lle_tbl >> $4 =3D {llt_link =3D {sle_next =3D 0xdeadc0dedeadc0de}, llt_af =3D -5590= 38242, >> llt_hsize =3D -559038242, lle_head =3D 0xdeadc0dedeadc0de, llt_ifp =3D >> 0xdeadc0dedeadc0de, llt_lookup =3D 0xdeadc0dedeadc0de, >> llt_alloc_entry =3D 0xdeadc0dedeadc0de, llt_delete_entry =3D >> 0xdeadc0dedeadc0de, llt_prefix_free =3D 0xdeadc0dedeadc0de, >> llt_dump_entry =3D 0xdeadc0dedeadc0de, llt_hash =3D 0xdeadc0dedeadc0de, >> llt_match_prefix =3D 0xdeadc0dedeadc0de, >> llt_free_entry =3D 0xdeadc0dedeadc0de, llt_foreach_entry =3D >> 0xdeadc0dedeadc0de, llt_link_entry =3D 0xdeadc0dedeadc0de, >> llt_unlink_entry =3D 0xdeadc0dedeadc0de, llt_fill_sa_entry =3D >> 0xdeadc0dedeadc0de, >> llt_free_tbl =3D 0xdeadc0dedeadc0de} >> >> :( >> >> Any ideas on where next to look? >> >> -adrian >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"