From owner-svn-src-all@freebsd.org Thu Mar 5 15:52:35 2020 Return-Path: Delivered-To: svn-src-all@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 502D226D13C; Thu, 5 Mar 2020 15:52:35 +0000 (UTC) (envelope-from kib@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 48YFcz0GC2z415Q; Thu, 5 Mar 2020 15:52:35 +0000 (UTC) (envelope-from kib@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 C13BE991C; Thu, 5 Mar 2020 15:52:34 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 025FqYoS000437; Thu, 5 Mar 2020 15:52:34 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 025FqYXc000436; Thu, 5 Mar 2020 15:52:34 GMT (envelope-from kib@FreeBSD.org) Message-Id: <202003051552.025FqYXc000436@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Thu, 5 Mar 2020 15:52:34 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r358676 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: kib X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 358676 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Mar 2020 15:52:35 -0000 Author: kib Date: Thu Mar 5 15:52:34 2020 New Revision: 358676 URL: https://svnweb.freebsd.org/changeset/base/358676 Log: buffer pager: deref ucred immediately after read. Ucred is passed to bread(9) so that non-local filesystems use proper credentials. But, since clean buffer might be cached unless buf_pager_relbuf is not enabled, it makes credentials to have extra reference until buffer is reclaimed. Ucred reference would prevent jail from destroying if creds are jailed. Dereferencing the read credentials on the valid buffer avoid that, and should be fine because the buffer is valid and does not need re-read. PR: 238032 Reported by: bz Reproduced and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D23775 Modified: head/sys/kern/vfs_bio.c Modified: head/sys/kern/vfs_bio.c ============================================================================== --- head/sys/kern/vfs_bio.c Thu Mar 5 15:51:44 2020 (r358675) +++ head/sys/kern/vfs_bio.c Thu Mar 5 15:52:34 2020 (r358676) @@ -5187,6 +5187,10 @@ again: br_flags, &bp); if (error != 0) goto end_pages; + if (bp->b_rcred == curthread->td_ucred) { + crfree(bp->b_rcred); + bp->b_rcred = NOCRED; + } if (LIST_EMPTY(&bp->b_dep)) { /* * Invalidation clears m->valid, but