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Tue, 21 Jan 2020 12:27:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579609652; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pVe7wvHKBehhCA55QXV1xkHtVCb1hkmnn0QWjHEjOXY=; b=DBzIqdiVw5FvkYgLuVh+IvXFfnzYitWx9zRB+ujK9fd+IS0/UQqCRbgnIsjk/rqkhi9x0e iuu2QRDImdk2erOuxfOTQHm/eQLNP+f5MdcTsSHEalGTP60oRlHTKDWMvZEwwVTnBvK3Jd 1vQ3TOYyCJkQwLPdSNr5fjCof3YRtBw= From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, berrange@redhat.com, slp@redhat.com, philmd@redhat.com Subject: [PATCH v2 037/109] virtiofsd: passthrough_ll: add fd_map to hide file descriptors Date: Tue, 21 Jan 2020 12:23:21 +0000 Message-Id: <20200121122433.50803-38-dgilbert@redhat.com> In-Reply-To: <20200121122433.50803-1-dgilbert@redhat.com> References: <20200121122433.50803-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: wv6TpE9FOx-ZbxFOxgLJmA-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] [fuzzy] X-Received-From: 205.139.110.61 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: , Cc: m.mizuma@jp.fujitsu.com, misono.tomohiro@jp.fujitsu.com 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 --- 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 927473d74a..327b5c1bf8 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -59,6 +59,7 @@ struct lo_map_elem { union { struct lo_inode *inode; struct lo_dirp *dirp; + int fd; ssize_t freelist; }; bool in_use; @@ -106,6 +107,7 @@ 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 { @@ -235,6 +237,20 @@ 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) { @@ -349,6 +365,22 @@ 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) { @@ -357,6 +389,7 @@ 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) { @@ -366,9 +399,14 @@ 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); @@ -388,7 +426,7 @@ 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); @@ -418,7 +456,7 @@ 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); } @@ -1095,7 +1133,18 @@ 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) { @@ -1139,6 +1188,7 @@ 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 @@ -1174,7 +1224,16 @@ 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) { @@ -1186,9 +1245,18 @@ 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 @@ -1196,7 +1264,7 @@ 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 @@ -1223,7 +1291,7 @@ 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) { @@ -1250,7 +1318,7 @@ 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, FUSE_BUF_SPLICE_MOVE); @@ -1265,7 +1333,7 @@ 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)) { @@ -1302,7 +1370,7 @@ 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; } @@ -1313,7 +1381,7 @@ 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); @@ -1325,7 +1393,7 @@ 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); } @@ -1550,17 +1618,19 @@ 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 { @@ -1575,7 +1645,7 @@ 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 { @@ -1660,6 +1730,7 @@ 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; @@ -1757,6 +1828,7 @@ 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