From: Ido Schimmel Date: Tue, 2 Dec 2025 17:44:11 +0000 (+0100) Subject: mlxsw: spectrum_router: Fix possible neighbour reference count leak X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b6b638bda240395dff49a87403b2e32493e56d2a;p=thirdparty%2Flinux.git mlxsw: spectrum_router: Fix possible neighbour reference count leak mlxsw_sp_router_schedule_work() takes a reference on a neighbour, expecting a work item to release it later on. However, we might fail to schedule the work item, in which case the neighbour reference count will be leaked. Fix by taking the reference just before scheduling the work item. Note that mlxsw_sp_router_schedule_work() can receive a NULL neighbour pointer, but neigh_clone() handles that correctly. Spotted during code review, did not actually observe the reference count leak. Fixes: 151b89f6025a ("mlxsw: spectrum_router: Reuse work neighbor initialization in work scheduler") Reviewed-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/ec2934ae4aca187a8d8c9329a08ce93cca411378.1764695650.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index a2033837182e..f4e9ecaeb104 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -2858,6 +2858,11 @@ static int mlxsw_sp_router_schedule_work(struct net *net, if (!net_work) return NOTIFY_BAD; + /* Take a reference to ensure the neighbour won't be destructed until + * we drop the reference in the work item. + */ + neigh_clone(n); + INIT_WORK(&net_work->work, cb); net_work->mlxsw_sp = router->mlxsw_sp; net_work->n = n; @@ -2881,11 +2886,6 @@ static int mlxsw_sp_router_schedule_neigh_work(struct mlxsw_sp_router *router, struct net *net; net = neigh_parms_net(n->parms); - - /* Take a reference to ensure the neighbour won't be destructed until we - * drop the reference in delayed work. - */ - neigh_clone(n); return mlxsw_sp_router_schedule_work(net, router, n, mlxsw_sp_router_neigh_event_work); }