From owner-svn-src-projects@freebsd.org Fri Jun 21 23:29:30 2019 Return-Path: Delivered-To: svn-src-projects@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 8161015C3969 for ; Fri, 21 Jun 2019 23:29:30 +0000 (UTC) (envelope-from asomers@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 21D5687225; Fri, 21 Jun 2019 23:29:30 +0000 (UTC) (envelope-from asomers@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 EAC8921D1; Fri, 21 Jun 2019 23:29:29 +0000 (UTC) (envelope-from asomers@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x5LNTTrh074640; Fri, 21 Jun 2019 23:29:29 GMT (envelope-from asomers@FreeBSD.org) Received: (from asomers@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x5LNTT4Q074639; Fri, 21 Jun 2019 23:29:29 GMT (envelope-from asomers@FreeBSD.org) Message-Id: <201906212329.x5LNTT4Q074639@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: asomers set sender to asomers@FreeBSD.org using -f From: Alan Somers Date: Fri, 21 Jun 2019 23:29:29 +0000 (UTC) To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r349282 - projects/fuse2/sys/fs/fuse X-SVN-Group: projects X-SVN-Commit-Author: asomers X-SVN-Commit-Paths: projects/fuse2/sys/fs/fuse X-SVN-Commit-Revision: 349282 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 21D5687225 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(-0.95)[-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-projects@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the src " projects" tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Jun 2019 23:29:30 -0000 Author: asomers Date: Fri Jun 21 23:29:29 2019 New Revision: 349282 URL: https://svnweb.freebsd.org/changeset/base/349282 Log: fusefs: fix corruption on short reads caused by r349279 Even if a short read is caused by EOF, it's still necessary to bzero the remaining buffer, because that buffer could become valid as a result of a future ftruncate or pwrite operation. Reported by: fsx Sponsored by: The FreeBSD Foundation Modified: projects/fuse2/sys/fs/fuse/fuse_io.c Modified: projects/fuse2/sys/fs/fuse/fuse_io.c ============================================================================== --- projects/fuse2/sys/fs/fuse/fuse_io.c Fri Jun 21 23:29:16 2019 (r349281) +++ projects/fuse2/sys/fs/fuse/fuse_io.c Fri Jun 21 23:29:29 2019 (r349282) @@ -899,33 +899,37 @@ fuse_io_strategy(struct vnode *vp, struct buf *bp) error = fuse_read_directbackend(vp, uiop, cred, fufh); if (!error && uiop->uio_resid) { - /* - * A short read with no error, when not using direct io, - * and when no writes are cached, indicates EOF. - * Update the file size accordingly. - */ + int nread = bp->b_bcount - uiop->uio_resid; + int left = uiop->uio_resid; + bzero((char *)bp->b_data + nread, left); + if (fuse_data_cache_mode != FUSE_CACHE_WB || (fvdat->flag & FN_SIZECHANGE) == 0) { - SDT_PROBE2(fusefs, , io, trace, 1, - "Short read of a clean file"); - /* + /* + * A short read with no error, when not using + * direct io, and when no writes are cached, + * indicates EOF. Update the file size + * accordingly. We must still bzero the + * remaining buffer so uninitialized data + * doesn't get exposed by a future truncate + * that extends the file. + * * XXX To prevent lock order problems, we must * truncate the file upstack */ + SDT_PROBE2(fusefs, , io, trace, 1, + "Short read of a clean file"); } else { /* * If dirty writes _are_ cached beyond EOF, * that indicates a newly created hole that the - * server doesn't know about. Fill it in. + * server doesn't know about. * XXX: we don't currently track whether dirty * writes are cached beyond EOF, before EOF, or * both. */ SDT_PROBE2(fusefs, , io, trace, 1, "Short read of a dirty file"); - int nread = bp->b_bcount - uiop->uio_resid; - int left = uiop->uio_resid; - bzero((char *)bp->b_data + nread, left); uiop->uio_resid = 0; }