From owner-svn-src-head@freebsd.org Mon May 27 12:41:42 2019 Return-Path: <owner-svn-src-head@freebsd.org> Delivered-To: svn-src-head@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 6B31B15813E6; Mon, 27 May 2019 12:41:42 +0000 (UTC) (envelope-from ae@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::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.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0E0556B7FE; Mon, 27 May 2019 12:41:42 +0000 (UTC) (envelope-from ae@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id D7701301D; Mon, 27 May 2019 12:41:41 +0000 (UTC) (envelope-from ae@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x4RCfflf047129; Mon, 27 May 2019 12:41:41 GMT (envelope-from ae@FreeBSD.org) Received: (from ae@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x4RCffTm047128; Mon, 27 May 2019 12:41:41 GMT (envelope-from ae@FreeBSD.org) Message-Id: <201905271241.x4RCffTm047128@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: ae set sender to ae@FreeBSD.org using -f From: "Andrey V. Elsukov" <ae@FreeBSD.org> Date: Mon, 27 May 2019 12:41:41 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348303 - head/sys/net X-SVN-Group: head X-SVN-Commit-Author: ae X-SVN-Commit-Paths: head/sys/net X-SVN-Commit-Revision: 348303 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 0E0556B7FE X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.96)[-0.955,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current <svn-src-head.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-head>, <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/> List-Post: <mailto:svn-src-head@freebsd.org> List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-head>, <mailto:svn-src-head-request@freebsd.org?subject=subscribe> X-List-Received-Date: Mon, 27 May 2019 12:41:42 -0000 Author: ae Date: Mon May 27 12:41:41 2019 New Revision: 348303 URL: https://svnweb.freebsd.org/changeset/base/348303 Log: Fix possible NULL pointer dereference. bpf_mtap() can invoke catchpacket() for already detached descriptor. And this can lead to NULL pointer dereference, since bd_bif pointer was reset to NULL in bpf_detachd_locked(). To avoid this, use NET_EPOCH_WAIT() when descriptor is removed from interface's descriptors list. After the wait it is safe to modify descriptor's content. Submitted by: kib Reported by: slavash MFC after: 1 week Modified: head/sys/net/bpf.c Modified: head/sys/net/bpf.c ============================================================================== --- head/sys/net/bpf.c Mon May 27 06:37:23 2019 (r348302) +++ head/sys/net/bpf.c Mon May 27 12:41:41 2019 (r348303) @@ -850,10 +850,15 @@ bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) /* Check if descriptor is attached */ if ((bp = d->bd_bif) == NULL) return; + /* + * Remove d from the interface's descriptor list. + * And wait until bpf_[m]tap*() will finish their possible work + * with descriptor. + */ + CK_LIST_REMOVE(d, bd_next); + NET_EPOCH_WAIT(); BPFD_LOCK(d); - /* Remove d from the interface's descriptor list. */ - CK_LIST_REMOVE(d, bd_next); /* Save bd_writer value */ error = d->bd_writer; ifp = bp->bif_ifp;