Hi Stefan,
On 2019/7/26 17:11, Stefan Hajnoczi wrote:
> Most lo_do_lookup() have already checked that the parent inode exists.
> lo_lookup() hasn't and can therefore hit a NULL pointer dereference when
> lo_inode(req, parent) returns NULL.
>
> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
> ---
> contrib/virtiofsd/passthrough_ll.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/contrib/virtiofsd/passthrough_ll.c
> b/contrib/virtiofsd/passthrough_ll.c
> index 9ae1381618..277a17fc03 100644
> --- a/contrib/virtiofsd/passthrough_ll.c
> +++ b/contrib/virtiofsd/passthrough_ll.c
> @@ -766,6 +766,10 @@ 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);
>
> + if (!dir) {
> + return EBADF;
> + }
> +
I worry about that dir will be released or set NULL just after NULL
checking. Or could we use some lock to prevent the simultaneity?
Thanks,
Jun
> memset(e, 0, sizeof(*e));
> e->attr_timeout = lo->timeout;
> e->entry_timeout = lo->timeout;
>
