From nobody Fri Oct 3 11:40:38 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1579808606; cv=none; d=zohomail.com; s=zohoarc; b=m3bgMfzKcL0c95RRdEsE/NXmDaEWaNx2SfBl17zrUOqjL90TMrKw6sjrKH+rH/H1VyMN5Vte+N3eyWbCb73jOSaTzQa8l2nHb8neWe94CgtW7LMC5qjce4D5xbNAaxkpdI0weMOSFgm7mAb/STTUDY0OBk6CgHSIkmTvqRpPc/M= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1579808606; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=b+gBkcT6H9ekHWJEoo9WCsPfsxwOkjZv4SrVsIPUVjg=; b=ACgRgghnS+FYWyFOOLqRz9v8QbnF6+/jEaxrSxA5AOTeUZb7u2EUo+YQQtv2EeaEDiZXs/wN8YD71FjrCcLC/dGBkIn1lp4V/mvAYP8CXudmPTs9ztUHkQJjs6l1S4IbnW03jV0RloMtqvrWePe1BFWsySEXVbCfPBSygpiTUOQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1579808606117560.9839485996642; Thu, 23 Jan 2020 11:43:26 -0800 (PST) Received: from localhost ([::1]:60422 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuiNw-0004Oq-Ui for importer@patchew.org; Thu, 23 Jan 2020 14:43:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41240) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iufds-0004sQ-C3 for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:47:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iufdq-0006Ut-Ah for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:47:40 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:47899 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iufdq-0006Uh-4f for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:47:38 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-325-jYu5Xoh3MVKa-QjhKJ5exg-1; Thu, 23 Jan 2020 11:47:36 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 84B976B313 for ; Thu, 23 Jan 2020 16:47:35 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-110.ams2.redhat.com [10.36.116.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id CDC6428993; Thu, 23 Jan 2020 16:47:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579798058; 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: in-reply-to:in-reply-to:references:references; bh=b+gBkcT6H9ekHWJEoo9WCsPfsxwOkjZv4SrVsIPUVjg=; b=HsvpTQvok4cXh4aU+Wcx6QpucshmaQ28cbQpvzbZeeA5uo5sCg2Dy2Zts0TmxdVrLPdhUN gQA7Uq4Bc+eBkajMBuDGFKr62HiFZuj88jSnXTMizxNlQeUFVxUXHexG58PXCUw1Sj1Rhl zKIGgubkwmY0V3eQrWp0CB3ky7PGDxs= From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com Subject: [PULL 038/108] virtiofsd: passthrough_ll: add fd_map to hide file descriptors Date: Thu, 23 Jan 2020 16:45:20 +0000 Message-Id: <20200123164630.91498-39-dgilbert@redhat.com> In-Reply-To: <20200123164630.91498-1-dgilbert@redhat.com> References: <20200123164630.91498-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: jYu5Xoh3MVKa-QjhKJ5exg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" From: Stefan Hajnoczi Do not expose file descriptor numbers to clients. This prevents the abuse of internal file descriptors (like stdin/stdout). Signed-off-by: Stefan Hajnoczi Fix from: Signed-off-by: Xiao Yang dgilbert: Added lseek Reviewed-by: Masayoshi Mizuma Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 116 +++++++++++++++++++++++++------ 1 file changed, 94 insertions(+), 22 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index 5f5a72fdbb..9815bfa5c5 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -60,6 +60,7 @@ struct lo_map_elem { union { struct lo_inode *inode; struct lo_dirp *dirp; + int fd; ssize_t freelist; }; bool in_use; @@ -107,6 +108,7 @@ struct lo_data { struct lo_inode root; /* protected by lo->mutex */ struct lo_map ino_map; /* protected by lo->mutex */ struct lo_map dirp_map; /* protected by lo->mutex */ + struct lo_map fd_map; /* protected by lo->mutex */ }; =20 static const struct fuse_opt lo_opts[] =3D { @@ -236,6 +238,20 @@ static void lo_map_remove(struct lo_map *map, size_t k= ey) map->freelist =3D key; } =20 +/* Assumes lo->mutex is held */ +static ssize_t lo_add_fd_mapping(fuse_req_t req, int fd) +{ + struct lo_map_elem *elem; + + elem =3D lo_map_alloc_elem(&lo_data(req)->fd_map); + if (!elem) { + return -1; + } + + elem->fd =3D fd; + return elem - lo_data(req)->fd_map.elems; +} + /* Assumes lo->mutex is held */ static ssize_t lo_add_dirp_mapping(fuse_req_t req, struct lo_dirp *dirp) { @@ -350,6 +366,22 @@ static int utimensat_empty_nofollow(struct lo_inode *i= node, return utimensat(AT_FDCWD, procname, tv, 0); } =20 +static int lo_fi_fd(fuse_req_t req, struct fuse_file_info *fi) +{ + struct lo_data *lo =3D lo_data(req); + struct lo_map_elem *elem; + + pthread_mutex_lock(&lo->mutex); + elem =3D lo_map_get(&lo->fd_map, fi->fh); + pthread_mutex_unlock(&lo->mutex); + + if (!elem) { + return -1; + } + + return elem->fd; +} + static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, int valid, struct fuse_file_info *fi) { @@ -358,6 +390,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, = struct stat *attr, struct lo_inode *inode; int ifd; int res; + int fd; =20 inode =3D lo_inode(req, ino); if (!inode) { @@ -367,9 +400,14 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,= struct stat *attr, =20 ifd =3D inode->fd; =20 + /* If fi->fh is invalid we'll report EBADF later */ + if (fi) { + fd =3D lo_fi_fd(req, fi); + } + if (valid & FUSE_SET_ATTR_MODE) { if (fi) { - res =3D fchmod(fi->fh, attr->st_mode); + res =3D fchmod(fd, attr->st_mode); } else { sprintf(procname, "/proc/self/fd/%i", ifd); res =3D chmod(procname, attr->st_mode); @@ -389,7 +427,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, = struct stat *attr, } if (valid & FUSE_SET_ATTR_SIZE) { if (fi) { - res =3D ftruncate(fi->fh, attr->st_size); + res =3D ftruncate(fd, attr->st_size); } else { sprintf(procname, "/proc/self/fd/%i", ifd); res =3D truncate(procname, attr->st_size); @@ -419,7 +457,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, = struct stat *attr, } =20 if (fi) { - res =3D futimens(fi->fh, tv); + res =3D futimens(fd, tv); } else { res =3D utimensat_empty_nofollow(inode, tv); } @@ -1096,7 +1134,18 @@ static void lo_create(fuse_req_t req, fuse_ino_t par= ent, const char *name, lo_restore_cred(&old); =20 if (!err) { - fi->fh =3D fd; + ssize_t fh; + + pthread_mutex_lock(&lo->mutex); + fh =3D lo_add_fd_mapping(req, fd); + pthread_mutex_unlock(&lo->mutex); + if (fh =3D=3D -1) { + close(fd); + fuse_reply_err(req, ENOMEM); + return; + } + + fi->fh =3D fh; err =3D lo_do_lookup(req, parent, name, &e); } if (lo->cache =3D=3D CACHE_NEVER) { @@ -1140,6 +1189,7 @@ static void lo_fsyncdir(fuse_req_t req, fuse_ino_t in= o, int datasync, static void lo_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info = *fi) { int fd; + ssize_t fh; char buf[64]; struct lo_data *lo =3D lo_data(req); =20 @@ -1175,7 +1225,16 @@ static void lo_open(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi) return (void)fuse_reply_err(req, errno); } =20 - fi->fh =3D fd; + pthread_mutex_lock(&lo->mutex); + fh =3D lo_add_fd_mapping(req, fd); + pthread_mutex_unlock(&lo->mutex); + if (fh =3D=3D -1) { + close(fd); + fuse_reply_err(req, ENOMEM); + return; + } + + fi->fh =3D fh; if (lo->cache =3D=3D CACHE_NEVER) { fi->direct_io =3D 1; } else if (lo->cache =3D=3D CACHE_ALWAYS) { @@ -1187,9 +1246,18 @@ static void lo_open(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi) static void lo_release(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) { + struct lo_data *lo =3D lo_data(req); + int fd; + (void)ino; =20 - close(fi->fh); + fd =3D lo_fi_fd(req, fi); + + pthread_mutex_lock(&lo->mutex); + lo_map_remove(&lo->fd_map, fi->fh); + pthread_mutex_unlock(&lo->mutex); + + close(fd); fuse_reply_err(req, 0); } =20 @@ -1197,7 +1265,7 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi) { int res; (void)ino; - res =3D close(dup(fi->fh)); + res =3D close(dup(lo_fi_fd(req, fi))); fuse_reply_err(req, res =3D=3D -1 ? errno : 0); } =20 @@ -1224,7 +1292,7 @@ static void lo_fsync(fuse_req_t req, fuse_ino_t ino, = int datasync, return (void)fuse_reply_err(req, errno); } } else { - fd =3D fi->fh; + fd =3D lo_fi_fd(req, fi); } =20 if (datasync) { @@ -1251,7 +1319,7 @@ static void lo_read(fuse_req_t req, fuse_ino_t ino, s= ize_t size, off_t offset, } =20 buf.buf[0].flags =3D FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK; - buf.buf[0].fd =3D fi->fh; + buf.buf[0].fd =3D lo_fi_fd(req, fi); buf.buf[0].pos =3D offset; =20 fuse_reply_data(req, &buf); @@ -1266,7 +1334,7 @@ static void lo_write_buf(fuse_req_t req, fuse_ino_t i= no, struct fuse_bufvec out_buf =3D FUSE_BUFVEC_INIT(fuse_buf_size(in_buf)); =20 out_buf.buf[0].flags =3D FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK; - out_buf.buf[0].fd =3D fi->fh; + out_buf.buf[0].fd =3D lo_fi_fd(req, fi); out_buf.buf[0].pos =3D off; =20 if (lo_debug(req)) { @@ -1303,7 +1371,7 @@ static void lo_fallocate(fuse_req_t req, fuse_ino_t i= no, int mode, off_t offset, (void)ino; =20 #ifdef CONFIG_FALLOCATE - err =3D fallocate(fi->fh, mode, offset, length); + err =3D fallocate(lo_fi_fd(req, fi), mode, offset, length); if (err < 0) { err =3D errno; } @@ -1314,7 +1382,7 @@ static void lo_fallocate(fuse_req_t req, fuse_ino_t i= no, int mode, off_t offset, return; } =20 - err =3D posix_fallocate(fi->fh, offset, length); + err =3D posix_fallocate(lo_fi_fd(req, fi), offset, length); #endif =20 fuse_reply_err(req, err); @@ -1326,7 +1394,7 @@ static void lo_flock(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi, int res; (void)ino; =20 - res =3D flock(fi->fh, op); + res =3D flock(lo_fi_fd(req, fi), op); =20 fuse_reply_err(req, res =3D=3D -1 ? errno : 0); } @@ -1551,17 +1619,19 @@ static void lo_copy_file_range(fuse_req_t req, fuse= _ino_t ino_in, off_t off_in, off_t off_out, struct fuse_file_info *fi_ou= t, size_t len, int flags) { + int in_fd, out_fd; ssize_t res; =20 - if (lo_debug(req)) - fuse_log(FUSE_LOG_DEBUG, - "lo_copy_file_range(ino=3D%" PRIu64 "/fd=3D%lu, " - "off=3D%lu, ino=3D%" PRIu64 "/fd=3D%lu, " - "off=3D%lu, size=3D%zd, flags=3D0x%x)\n", - ino_in, fi_in->fh, off_in, ino_out, fi_out->fh, off_out, = len, - flags); + in_fd =3D lo_fi_fd(req, fi_in); + out_fd =3D lo_fi_fd(req, fi_out); + + fuse_log(FUSE_LOG_DEBUG, + "lo_copy_file_range(ino=3D%" PRIu64 "/fd=3D%d, " + "off=3D%lu, ino=3D%" PRIu64 "/fd=3D%d, " + "off=3D%lu, size=3D%zd, flags=3D0x%x)\n", + ino_in, in_fd, off_in, ino_out, out_fd, off_out, len, flags); =20 - res =3D copy_file_range(fi_in->fh, &off_in, fi_out->fh, &off_out, len,= flags); + res =3D copy_file_range(in_fd, &off_in, out_fd, &off_out, len, flags); if (res < 0) { fuse_reply_err(req, -errno); } else { @@ -1576,7 +1646,7 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, = off_t off, int whence, off_t res; =20 (void)ino; - res =3D lseek(fi->fh, off, whence); + res =3D lseek(lo_fi_fd(req, fi), off, whence); if (res !=3D -1) { fuse_reply_lseek(req, res); } else { @@ -1661,6 +1731,7 @@ int main(int argc, char *argv[]) root_elem->inode =3D &lo.root; =20 lo_map_init(&lo.dirp_map); + lo_map_init(&lo.fd_map); =20 if (fuse_parse_cmdline(&args, &opts) !=3D 0) { return 1; @@ -1758,6 +1829,7 @@ err_out2: err_out1: fuse_opt_free_args(&args); =20 + lo_map_destroy(&lo.fd_map); lo_map_destroy(&lo.dirp_map); lo_map_destroy(&lo.ino_map); =20 --=20 2.24.1