diff mbox series

[044/104] virtiofsd: prevent ".." escape in lo_do_lookup()

Message ID 20191212163904.159893-45-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: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tools/virtiofsd/passthrough_ll.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Sergio Lopez Jan. 16, 2020, 2:33 p.m. UTC | #1 
Dr. David Alan Gilbert (git) <dgilbert@redhat.com> writes:

> From: Stefan Hajnoczi <stefanha@redhat.com>
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  tools/virtiofsd/passthrough_ll.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

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 84e9d8916f..cf5b43531a 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -624,12 +624,17 @@  static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
     int res;
     int saverr;
     struct lo_data *lo = lo_data(req);
-    struct lo_inode *inode;
+    struct lo_inode *inode, *dir = lo_inode(req, parent);
 
     memset(e, 0, sizeof(*e));
     e->attr_timeout = lo->timeout;
     e->entry_timeout = lo->timeout;
 
+    /* Do not allow escaping root directory */
+    if (dir == &lo->root && strcmp(name, "..") == 0) {
+        name = ".";
+    }
+
     newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
     if (newfd == -1) {
         goto out_err;