From owner-dev-commits-src-branches@freebsd.org Tue Jun 8 13:38:05 2021 Return-Path: Delivered-To: dev-commits-src-branches@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 6BDA465F90D; Tue, 8 Jun 2021 13:38:05 +0000 (UTC) (envelope-from git@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) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FzrsT1Fpnz4qJ9; Tue, 8 Jun 2021 13:38:05 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id EB01A1D81; Tue, 8 Jun 2021 13:38:04 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 158Dc43J074975; Tue, 8 Jun 2021 13:38:04 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 158Dc4tL074974; Tue, 8 Jun 2021 13:38:04 GMT (envelope-from git) Date: Tue, 8 Jun 2021 13:38:04 GMT Message-Id: <202106081338.158Dc4tL074974@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: cb5fe9aa9fa0 - stable/13 - amd64: Clear the local TSS when creating a new thread MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: cb5fe9aa9fa0376078abc173b27605b6096dc681 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-branches@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commits to the stable branches of the FreeBSD src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Jun 2021 13:38:05 -0000 The branch stable/13 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=cb5fe9aa9fa0376078abc173b27605b6096dc681 commit cb5fe9aa9fa0376078abc173b27605b6096dc681 Author: Mark Johnston AuthorDate: 2021-06-01 23:38:22 +0000 Commit: Mark Johnston CommitDate: 2021-06-08 13:33:59 +0000 amd64: Clear the local TSS when creating a new thread Otherwise it is copied from the creating thread. Then, if either thread exits, the other is left with a dangling pointer, typically resulting in a page fault upon the next context switch. Reported by: syzkaller Reviewed by: kib Sponsored by: The FreeBSD Foundation (cherry picked from commit 8cd05b883330049d536a40e2f4c9ff92d0e6944e) --- sys/amd64/amd64/vm_machdep.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c index 1acc5dc55c85..7d65269410e0 100644 --- a/sys/amd64/amd64/vm_machdep.c +++ b/sys/amd64/amd64/vm_machdep.c @@ -189,6 +189,8 @@ copy_thread(struct thread *td1, struct thread *td2) * pcb2->pcb_[fg]sbase: cloned above */ + pcb2->pcb_tssp = NULL; + /* Setup to release spin count in fork_exit(). */ td2->td_md.md_spinlock_count = 1; td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;