From: Jan Beulich jbeulich@suse.com
commit 2991397d23ec597405b116d96de3813420bdcbc3 upstream.
Commit 3194a1746e8a ("xen-netback: don't "handle" error by BUG()") dropped respective a BUG_ON() without noticing that with this the variable's value wouldn't be consumed anymore. With gnttab_set_map_op() setting all status fields to a non-zero value, in case of an error no slot should have a status of GNTST_okay (zero).
This is part of XSA-367.
Cc: stable@vger.kernel.org Reported-by: kernel test robot lkp@intel.com Signed-off-by: Jan Beulich jbeulich@suse.com Reviewed-by: Juergen Gross jgross@suse.com Link: https://lore.kernel.org/r/d933f495-619a-0086-5fb4-1ec3cf81a8fc@suse.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/xen-netback/netback.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
--- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1792,11 +1792,21 @@ int xenvif_tx_action(struct xenvif_queue return 0;
gnttab_batch_copy(queue->tx_copy_ops, nr_cops); - if (nr_mops != 0) + if (nr_mops != 0) { ret = gnttab_map_refs(queue->tx_map_ops, NULL, queue->pages_to_map, nr_mops); + if (ret) { + unsigned int i; + + netdev_err(queue->vif->dev, "Map fail: nr %u ret %d\n", + nr_mops, ret); + for (i = 0; i < nr_mops; ++i) + WARN_ON_ONCE(queue->tx_map_ops[i].status == + GNTST_okay); + } + }
work_done = xenvif_tx_submit(queue);