From nobody Sun Jan 02 20:56:17 2022 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id A913D1918882; Sun, 2 Jan 2022 20:56:18 +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 4JRrl61Qr8z3Bmy; Sun, 2 Jan 2022 20:56:18 +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 11E7E18DB9; Sun, 2 Jan 2022 20:56:18 +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 202KuHQc004262; Sun, 2 Jan 2022 20:56:17 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 202KuHDI004261; Sun, 2 Jan 2022 20:56:17 GMT (envelope-from git) Date: Sun, 2 Jan 2022 20:56:17 GMT Message-Id: <202201022056.202KuHDI004261@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Jessica Clarke Subject: git: 324150d6dab8 - main - ufs: Avoid subobject overflow in snapshot expunge code List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: jrtc27 X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 324150d6dab8a5fcde98c6cc1869da0becb7c3bb Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1641156978; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=2tWauTwmAGAqeD/p7aaHGW2uz11VK/bPVZ9L08l1yJY=; b=QcUs0v4DpyRlZcxjT27MOCXhlLOhZhRqGNfRwMLD2ub7dnpKxR4KirxkPyoOv//5XqLn6m ClNrvzfv6+KcXJZ1XaeAugcsM18MSd22GCKlbE1KQuPSziQsLHB2DAtryGvT/qlVFkgcZb 1k8o9OKKrLUq2qtS0NpwceGyjtv7ejYgI55FEpCv8LJeDAB9a4PGvEuOmkyRRKMbjzxFPX w03Srrd4YVEG9pO72X7a/g0bh/uk+xFCkF3F21cXaTlTJaS3Opg35o4dp/4JJouTg59Prm 2MIlVJCppv6sh8DXS5+qAH4jfBH/01rQUhcN2eUgEjZtu/Ez8/tlM4DEavFqAg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1641156978; a=rsa-sha256; cv=none; b=F/lDx5ZXSWZa0FF+8NCb93h02jI6Jo084oN8T8l1YU024uLMC6FHJmYGdl2ZXq9fgnKqoy w5tFQwWHUzVL4OeCOH9GMEw4bU1qJ+PJfXLf8tVucl6PutOEvqUOb66XV5RjchbOrL5lwA t3paBUGaDoWUAXAZoE5M74f/vxwPf1rS2fAgp/MqRcUcCI+YjUt3So2pGW5VAOw+gPA8p6 biI1shrjj8StvB8OPTLiegx6JNuUzWNy519jUkuHtFG1fC0yDC31t/f+++CoNy9nqhwNBL tzxcZzGLPAtHvf4Tb7+WBtfYQopLTowz+u8PLfA7MYPDYOqPT9g1lWENJNzh+g== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by jrtc27: URL: https://cgit.FreeBSD.org/src/commit/?id=324150d6dab8a5fcde98c6cc1869da0becb7c3bb commit 324150d6dab8a5fcde98c6cc1869da0becb7c3bb Author: Jessica Clarke AuthorDate: 2022-01-02 20:55:49 +0000 Commit: Jessica Clarke CommitDate: 2022-01-02 20:55:49 +0000 ufs: Avoid subobject overflow in snapshot expunge code The code here tries to be smart and zeroes out both di_db and di_ib with a single bzero call, thereby overrunning the di_db subobject. This is fine on most architectures, if a little dodgy. However, on CHERI, the compiler can optionally restrict the bounds on pointers to subobjects to just that subobject, in order to mitigate intra-object buffer overflows, and this is enabled in CheriBSD's pure-capability kernels. Instead, use separate bzero calls for each array, and let the compiler optimise it as it sees fit; even if it's not generating inline zeroing code, Clang will happily optimise two consecutive bzero's to a single larger call. Reviewed by: mckusick Differential Revision: https://reviews.freebsd.org/D33651 --- sys/ufs/ffs/ffs_snapshot.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sys/ufs/ffs/ffs_snapshot.c b/sys/ufs/ffs/ffs_snapshot.c index 59e5012c0019..c5063bf5f747 100644 --- a/sys/ufs/ffs/ffs_snapshot.c +++ b/sys/ufs/ffs/ffs_snapshot.c @@ -1084,7 +1084,8 @@ expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) dip->di_size = 0; dip->di_blocks = 0; dip->di_flags &= ~SF_SNAPSHOT; - bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t)); + bzero(dip->di_db, UFS_NDADDR * sizeof(ufs1_daddr_t)); + bzero(dip->di_ib, UFS_NIADDR * sizeof(ufs1_daddr_t)); bdwrite(bp); /* * Now go through and expunge all the blocks in the file @@ -1366,7 +1367,8 @@ expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) dip->di_size = 0; dip->di_blocks = 0; dip->di_flags &= ~SF_SNAPSHOT; - bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t)); + bzero(dip->di_db, UFS_NDADDR * sizeof(ufs2_daddr_t)); + bzero(dip->di_ib, UFS_NIADDR * sizeof(ufs2_daddr_t)); if (clearmode || cancelip->i_effnlink == 0) dip->di_mode = 0; else