On Wed, Jun 07, 2023 at 08:35:29PM +0200, Greg Kroah-Hartman wrote: > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe. > > > > On Tue, Jun 06, 2023 at 11:28:31AM -0700, Samuel Mendoza-Jonas wrote: > > From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > > > > commit fb4554c2232e44d595920f4d5c66cf8f7d13f9bc upstream. > > > > Descriptor table is a shared resource; two fget() on the same descriptor > > may return different struct file references. get_tap_ptr_ring() is > > called after we'd found (and pinned) the socket we'll be using and it > > tries to find the private tun/tap data structures associated with it. > > Redoing the lookup by the same file descriptor we'd used to get the > > socket is racy - we need to same struct file. > > > > Thanks to Jason for spotting a braino in the original variant of patch - > > I'd missed the use of fd == -1 for disabling backend, and in that case > > we can end up with sock == NULL and sock != oldsock. > > > > Cc: stable@xxxxxxxxxx > > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> > > Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > I did not sign off on this patch, where did that come from? > > Please be more careful. > > thanks, > > greg k-h Ah my apologies, that must have come from the commit to the other stable branches. Thanks, Sam
