diff mbox series

[070/104] virtiofsd: fail when parent inode isn't known in lo_do_lookup()

Message ID 20191212163904.159893-71-dgilbert@redhat.com (mailing list archive)
State New, archived
Headers show
Series virtiofs daemon [all] | expand

Commit Message

Dr. David Alan Gilbert Dec. 12, 2019, 4:38 p.m. UTC
From: Miklos Szeredi <mszeredi@redhat.com>

The Linux file handle APIs (struct export_operations) can access inodes
that are not attached to parents because path name traversal is not
performed.  Refuse if there is no parent in lo_do_lookup().

Also clean up lo_do_lookup() while we're here.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tools/virtiofsd/passthrough_ll.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

Comments

Misono Tomohiro Jan. 16, 2020, 7:17 a.m. UTC | #1
Looks good to me.
 Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>

> ---
>  tools/virtiofsd/passthrough_ll.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
> index 1618db5a92..ef8b88e3d1 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -778,6 +778,15 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
>      struct lo_data *lo = lo_data(req);
>      struct lo_inode *inode, *dir = lo_inode(req, parent);
>  
> +    /*
> +     * name_to_handle_at() and open_by_handle_at() can reach here with fuse
> +     * mount point in guest, but we don't have its inode info in the
> +     * ino_map.
> +     */
> +    if (!dir) {
> +        return ENOENT;
> +    }
> +
>      memset(e, 0, sizeof(*e));
>      e->attr_timeout = lo->timeout;
>      e->entry_timeout = lo->timeout;
> @@ -787,7 +796,7 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
>          name = ".";
>      }
>  
> -    newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
> +    newfd = openat(dir->fd, name, O_PATH | O_NOFOLLOW);
>      if (newfd == -1) {
>          goto out_err;
>      }
> @@ -797,7 +806,7 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
>          goto out_err;
>      }
>  
> -    inode = lo_find(lo_data(req), &e->attr);
> +    inode = lo_find(lo, &e->attr);
>      if (inode) {
>          close(newfd);
>          newfd = -1;
> @@ -813,6 +822,7 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
>          inode->is_symlink = S_ISLNK(e->attr.st_mode);
>          inode->refcount = 1;
>          inode->fd = newfd;
> +        newfd = -1;
>          inode->ino = e->attr.st_ino;
>          inode->dev = e->attr.st_dev;
Sergio Lopez Pascual Jan. 20, 2020, 10:08 a.m. UTC | #2
Dr. David Alan Gilbert (git) <dgilbert@redhat.com> writes:

> From: Miklos Szeredi <mszeredi@redhat.com>
>
> The Linux file handle APIs (struct export_operations) can access inodes
> that are not attached to parents because path name traversal is not
> performed.  Refuse if there is no parent in lo_do_lookup().
>
> Also clean up lo_do_lookup() while we're here.
>
> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  tools/virtiofsd/passthrough_ll.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)

Reviewed-by: Sergio Lopez <slp@redhat.com>
diff mbox series

Patch

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 1618db5a92..ef8b88e3d1 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -778,6 +778,15 @@  static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
     struct lo_data *lo = lo_data(req);
     struct lo_inode *inode, *dir = lo_inode(req, parent);
 
+    /*
+     * name_to_handle_at() and open_by_handle_at() can reach here with fuse
+     * mount point in guest, but we don't have its inode info in the
+     * ino_map.
+     */
+    if (!dir) {
+        return ENOENT;
+    }
+
     memset(e, 0, sizeof(*e));
     e->attr_timeout = lo->timeout;
     e->entry_timeout = lo->timeout;
@@ -787,7 +796,7 @@  static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
         name = ".";
     }
 
-    newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
+    newfd = openat(dir->fd, name, O_PATH | O_NOFOLLOW);
     if (newfd == -1) {
         goto out_err;
     }
@@ -797,7 +806,7 @@  static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
         goto out_err;
     }
 
-    inode = lo_find(lo_data(req), &e->attr);
+    inode = lo_find(lo, &e->attr);
     if (inode) {
         close(newfd);
         newfd = -1;
@@ -813,6 +822,7 @@  static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
         inode->is_symlink = S_ISLNK(e->attr.st_mode);
         inode->refcount = 1;
         inode->fd = newfd;
+        newfd = -1;
         inode->ino = e->attr.st_ino;
         inode->dev = e->attr.st_dev;