[PATCH net-next v1 03/11] xdp: fix leak of IDA cyclic id if rhashtable_insert_slow fails

[Jesper Dangaard Brouer]

Fix error handling case, where inserting ID with rhashtable_insert_slow
fails in xdp_rxq_info_reg_mem_model, which leads to never releasing the IDA
ID, as the lookup in xdp_rxq_info_unreg_mem_model fails and thus
ida_simple_remove() is never called.

Fix by releasing ID via ida_simple_remove(), and mark xdp_rxq->mem.id with
zero, which is already checked in xdp_rxq_info_unreg_mem_model().

Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
---
 net/core/xdp.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/xdp.c b/net/core/xdp.c
index 4b2b194f4f1f..762abeb89847 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -301,6 +301,8 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
        /* Insert allocator into ID lookup table */
        ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
        if (IS_ERR(ptr)) {
+               ida_simple_remove(&mem_id_pool, xdp_rxq->mem.id);
+               xdp_rxq->mem.id = 0;
                errno = PTR_ERR(ptr);
                goto err;
        }