From owner-freebsd-bugs@freebsd.org Wed Jun 19 15:05:51 2019 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7283215BB54C for ; Wed, 19 Jun 2019 15:05:51 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 08D8F69CBC for ; Wed, 19 Jun 2019 15:05:51 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id BD8D315BB54B; Wed, 19 Jun 2019 15:05:50 +0000 (UTC) Delivered-To: bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9B1F115BB54A for ; Wed, 19 Jun 2019 15:05:50 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 378B469CB9 for ; Wed, 19 Jun 2019 15:05:50 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 6F6998B6 for ; Wed, 19 Jun 2019 15:05:49 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x5JF5neh053497 for ; Wed, 19 Jun 2019 15:05:49 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x5JF5n2Q053488 for bugs@FreeBSD.org; Wed, 19 Jun 2019 15:05:49 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 238707] [PATCH][LOR] Lock order reversal: rtentry vs "nd6 list" Date: Wed, 19 Jun 2019 15:05:49 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: arnaud.ysmal@stormshield.eu X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Jun 2019 15:05:51 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D238707 Bug ID: 238707 Summary: [PATCH][LOR] Lock order reversal: rtentry vs "nd6 list" Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: arnaud.ysmal@stormshield.eu Created attachment 205221 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D205221&action= =3Dedit Patch to move the unlock of the rtentry just before the call of rt_notifyde= lete Hi, I encounter the following lor in the function rtrequest1_fib (in the RTM_DE= LETE case of the switch). When deleting a rtentry, it is returned locked by rt_unlinkrte then during = the call to rt_notifydelete the "nd6 list" lock is locked. In the RTM_ADD switch case, the old_rt in unlink by rt_unlinkrte then unloc= ked and passed to the rt_notifydelete, with this I assume there is no issue to = call rt_notifydelete with a rtentry unlocked. The patch enclosed move the unlock of the rtentry just before the call of rt_notifydelete. The witness trace is the following: [2019-05-01 23:21:12] lock order reversal: [2019-05-01 23:21:12] 1st 0xfffff80036683998 rtentry (rtentry) @ net/route.c:1230 [2019-05-01 23:21:12] 2nd 0xffffffff8147fe68 nd6 list (nd6 list) @ netinet6/nd6_rtr.c:545 [2019-05-01 23:21:12] stack backtrace: [2019-05-01 23:21:12] #0 0xffffffff80544e10 at witness_debugger+0x70 [2019-05-01 23:21:12] #1 0xffffffff80544d10 at witness_checkorder+0xc90 [2019-05-01 23:21:12] #2 0xffffffff804ecfda at __rw_rlock+0x3a [2019-05-01 23:21:12] #3 0xffffffff8068f798 at defrouter_lookup+0x28 [2019-05-01 23:21:12] #4 0xffffffff80689b40 at nd6_rtrequest+0x50 [2019-05-01 23:21:12] #5 0xffffffff805f4a66 at rtrequest1_fib+0x286 [2019-05-01 23:21:12] #6 0xffffffff805f89ff at route_output+0x77f [2019-05-01 23:21:12] #7 0xffffffff8056ef7f at sosend_generic+0x43f [2019-05-01 23:21:12] #8 0xffffffff8054f90d at soo_write+0x2d [2019-05-01 23:21:12] #9 0xffffffff80548b0a at dofilewrite+0x8a [2019-05-01 23:21:12] #10 0xffffffff805487e8 at kern_writev+0x68 [2019-05-01 23:21:12] #11 0xffffffff80548776 at sys_write+0x86 [2019-05-01 23:21:12] #12 0xffffffff80753bf9 at amd64_syscall+0x299 [2019-05-01 23:21:12] #13 0xffffffff80734bed at fast_syscall_common+0x101 --=20 You are receiving this mail because: You are the assignee for the bug.=