devlink: rate: Unset parent pointer in devl_rate_nodes_destroy

2025-12-01T10:43:33+00:00

[ Upstream commit f94c1a114ac209977bdf5ca841b98424295ab1f0 ] The function devl_rate_nodes_destroy is documented to "Unset parent for all rate objects". However, it was only calling the driver-specific `rate_leaf_parent_set` or `rate_node_parent_set` ops and decrementing the parent's refcount, without actually setting the `devlink_rate->parent` pointer to NULL. This leaves a dangling pointer in the `devlink_rate` struct, which cause refcount error in netdevsim[1] and mlx5[2]. In addition, this is inconsistent with the behavior of `devlink_nl_rate_parent_node_set`, where the parent pointer is correctly cleared. This patch fixes the issue by explicitly setting `devlink_rate->parent` to NULL after notifying the driver, thus fulfilling the function's documented behavior for all rate objects. [1] repro steps: echo 1 > /sys/bus/netdevsim/new_device devlink dev eswitch set netdevsim/netdevsim1 mode switchdev echo 1 > /sys/bus/netdevsim/devices/netdevsim1/sriov_numvfs devlink port function rate add netdevsim/netdevsim1/test_node devlink port function rate set netdevsim/netdevsim1/128 parent test_node echo 1 > /sys/bus/netdevsim/del_device dmesg: refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 8 PID: 1530 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0 CPU: 8 UID: 0 PID: 1530 Comm: bash Not tainted 6.18.0-rc4+ #1 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:refcount_warn_saturate+0x42/0xe0 Call Trace: devl_rate_leaf_destroy+0x8d/0x90 __nsim_dev_port_del+0x6c/0x70 [netdevsim] nsim_dev_reload_destroy+0x11c/0x140 [netdevsim] nsim_drv_remove+0x2b/0xb0 [netdevsim] device_release_driver_internal+0x194/0x1f0 bus_remove_device+0xc6/0x130 device_del+0x159/0x3c0 device_unregister+0x1a/0x60 del_device_store+0x111/0x170 [netdevsim] kernfs_fop_write_iter+0x12e/0x1e0 vfs_write+0x215/0x3d0 ksys_write+0x5f/0xd0 do_syscall_64+0x55/0x10f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [2] devlink dev eswitch set pci/0000:08:00.0 mode switchdev devlink port add pci/0000:08:00.0 flavour pcisf pfnum 0 sfnum 1000 devlink port function rate add pci/0000:08:00.0/group1 devlink port function rate set pci/0000:08:00.0/32768 parent group1 modprobe -r mlx5_ib mlx5_fwctl mlx5_core dmesg: refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 7 PID: 16151 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0 CPU: 7 UID: 0 PID: 16151 Comm: bash Not tainted 6.17.0-rc7_for_upstream_min_debug_2025_10_02_12_44 #1 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:refcount_warn_saturate+0x42/0xe0 Call Trace: devl_rate_leaf_destroy+0x8d/0x90 mlx5_esw_offloads_devlink_port_unregister+0x33/0x60 [mlx5_core] mlx5_esw_offloads_unload_rep+0x3f/0x50 [mlx5_core] mlx5_eswitch_unload_sf_vport+0x40/0x90 [mlx5_core] mlx5_sf_esw_event+0xc4/0x120 [mlx5_core] notifier_call_chain+0x33/0xa0 blocking_notifier_call_chain+0x3b/0x50 mlx5_eswitch_disable_locked+0x50/0x110 [mlx5_core] mlx5_eswitch_disable+0x63/0x90 [mlx5_core] mlx5_unload+0x1d/0x170 [mlx5_core] mlx5_uninit_one+0xa2/0x130 [mlx5_core] remove_one+0x78/0xd0 [mlx5_core] pci_device_remove+0x39/0xa0 device_release_driver_internal+0x194/0x1f0 unbind_store+0x99/0xa0 kernfs_fop_write_iter+0x12e/0x1e0 vfs_write+0x215/0x3d0 ksys_write+0x5f/0xd0 do_syscall_64+0x53/0x1f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Fixes: d75559845078 ("devlink: Allow setting parent node of rate objects") Signed-off-by: Shay Drory Reviewed-by: Carolina Jubran Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/1763381149-1234377-1-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

devlink: introduce a helper for netlink multicast send

2023-12-19T14:31:40+00:00

Introduce a helper devlink_nl_notify_send() so each object notification function does not have to call genlmsg_multicast_netns() with the same arguments. Signed-off-by: Jiri Pirko Signed-off-by: Paolo Abeni

devlink: send notifications only if there are listeners

2023-12-19T14:31:40+00:00

Introduce devlink_nl_notify_need() helper and using it to check at the beginning of notification functions to avoid overhead of composing notification messages in case nobody listens. Signed-off-by: Jiri Pirko Signed-off-by: Paolo Abeni

devlink: use devl_is_registered() helper instead xa_get_mark()

2023-12-19T14:31:40+00:00

Instead of checking the xarray mark directly using xa_get_mark() helper use devl_is_registered() helper which wraps it up. Note that there are couple more users of xa_get_mark() left which are going to be handled by the next patch. Signed-off-by: Jiri Pirko Signed-off-by: Paolo Abeni

devlink: rename netlink callback to be aligned with the generated ones

2023-10-23T23:12:47+00:00

All remaining doit and dumpit netlink callback functions are going to be used by generated split ops. They expect certain name format. Rename the callback to be aligned with generated names. Signed-off-by: Jiri Pirko Reviewed-by: Jacob Keller Link: https://lore.kernel.org/r/20231021112711.660606-8-jiri@resnulli.us Signed-off-by: Jakub Kicinski

devlink: push rate related code into separate file

2023-08-28T15:02:23+00:00

Cut out another chunk from leftover.c and put rate related code into a separate file. Signed-off-by: Jiri Pirko Link: https://lore.kernel.org/r/20230828061657.300667-12-jiri@resnulli.us Signed-off-by: Jakub Kicinski

kernel/linux.git/net/devlink/rate.c, branch v6.12.80

devlink: rate: Unset parent pointer in devl_rate_nodes_destroy

devlink: introduce a helper for netlink multicast send

devlink: send notifications only if there are listeners

devlink: use devl_is_registered() helper instead xa_get_mark()

devlink: rename netlink callback to be aligned with the generated ones

devlink: push rate related code into separate file