165 lines
4.9 KiB
Diff
165 lines
4.9 KiB
Diff
From 69ac47502848c37ca3ede00f432c0675d9eef42c Mon Sep 17 00:00:00 2001
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From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
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Date: Mon, 27 Jan 2020 19:01:18 +0100
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Subject: [PATCH 047/116] virtiofsd: validate path components
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
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Message-id: <20200127190227.40942-44-dgilbert@redhat.com>
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Patchwork-id: 93498
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O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 043/112] virtiofsd: validate path components
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Bugzilla: 1694164
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RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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RH-Acked-by: Sergio Lopez Pascual <slp@redhat.com>
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From: Stefan Hajnoczi <stefanha@redhat.com>
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Several FUSE requests contain single path components. A correct FUSE
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client sends well-formed path components but there is currently no input
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validation in case something went wrong or the client is malicious.
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Refuse ".", "..", and paths containing '/' when we expect a path
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component.
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Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
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Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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(cherry picked from commit 25dae28c58d7e706b5d5db99042c9db3cef2e657)
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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tools/virtiofsd/passthrough_ll.c | 59 ++++++++++++++++++++++++++++++++++++----
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1 file changed, 53 insertions(+), 6 deletions(-)
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diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
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index ac380ef..e375406 100644
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--- a/tools/virtiofsd/passthrough_ll.c
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+++ b/tools/virtiofsd/passthrough_ll.c
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@@ -133,6 +133,21 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n);
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static struct lo_inode *lo_find(struct lo_data *lo, struct stat *st);
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+static int is_dot_or_dotdot(const char *name)
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+{
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+ return name[0] == '.' &&
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+ (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'));
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+}
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+
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+/* Is `path` a single path component that is not "." or ".."? */
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+static int is_safe_path_component(const char *path)
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+{
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+ if (strchr(path, '/')) {
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+ return 0;
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+ }
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+
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+ return !is_dot_or_dotdot(path);
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+}
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static struct lo_data *lo_data(fuse_req_t req)
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{
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@@ -681,6 +696,15 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
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parent, name);
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}
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+ /*
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+ * Don't use is_safe_path_component(), allow "." and ".." for NFS export
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+ * support.
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+ */
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+ if (strchr(name, '/')) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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+
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err = lo_do_lookup(req, parent, name, &e);
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if (err) {
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fuse_reply_err(req, err);
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@@ -762,6 +786,11 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent,
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struct fuse_entry_param e;
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struct lo_cred old = {};
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+ if (!is_safe_path_component(name)) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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+
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dir = lo_inode(req, parent);
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if (!dir) {
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fuse_reply_err(req, EBADF);
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@@ -863,6 +892,11 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t parent,
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struct fuse_entry_param e;
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int saverr;
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+ if (!is_safe_path_component(name)) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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+
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inode = lo_inode(req, ino);
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if (!inode) {
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fuse_reply_err(req, EBADF);
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@@ -904,6 +938,10 @@ out_err:
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static void lo_rmdir(fuse_req_t req, fuse_ino_t parent, const char *name)
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{
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int res;
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+ if (!is_safe_path_component(name)) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
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@@ -916,6 +954,11 @@ static void lo_rename(fuse_req_t req, fuse_ino_t parent, const char *name,
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{
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int res;
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+ if (!is_safe_path_component(name) || !is_safe_path_component(newname)) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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+
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if (flags) {
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fuse_reply_err(req, EINVAL);
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return;
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@@ -930,6 +973,11 @@ static void lo_unlink(fuse_req_t req, fuse_ino_t parent, const char *name)
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{
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int res;
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+ if (!is_safe_path_component(name)) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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+
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res = unlinkat(lo_fd(req, parent), name, 0);
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fuse_reply_err(req, res == -1 ? errno : 0);
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@@ -1093,12 +1141,6 @@ out_err:
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fuse_reply_err(req, error);
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}
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-static int is_dot_or_dotdot(const char *name)
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-{
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- return name[0] == '.' &&
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- (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'));
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-}
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-
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static void lo_do_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
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off_t offset, struct fuse_file_info *fi, int plus)
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{
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@@ -1248,6 +1290,11 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
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parent, name);
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}
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+ if (!is_safe_path_component(name)) {
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+ fuse_reply_err(req, EINVAL);
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+ return;
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+ }
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+
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err = lo_change_cred(req, &old);
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if (err) {
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goto out;
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--
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1.8.3.1
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