From: Vadim Pasternak vadimp@mellanox.com
[ Upstream commit 8c2eb7b6468ad4aa5600aed01aa0715f921a3f8b ]
Add devm_free_irq() call to mlxreg-hotplug remove() for clean release of devices irq resource. Fix debugobjects warning triggered by rmmod It prevents of use-after-free memory, related to mlxreg_hotplug_work_handler.
Issue has been reported as debugobjects warning triggered by 'rmmod mlxtreg-hotplug' flow, while running kernel with CONFIG_DEBUG_OBJECTS* options.
[ 2489.623551] ODEBUG: free active (active state 0) object type: work_struct hint: mlxreg_hotplug_work_handler+0x0/0x7f0 [mlxreg_hotplug] [ 2489.637097] WARNING: CPU: 5 PID: 3924 at lib/debugobjects.c:328 debug_print_object+0xfe/0x180 [ 2489.637165] RIP: 0010:debug_print_object+0xfe/0x180 ? [ 2489.637214] Call Trace: [ 2489.637225] __debug_check_no_obj_freed+0x25e/0x320 [ 2489.637231] kfree+0x82/0x110 [ 2489.637238] release_nodes+0x33c/0x4e0 [ 2489.637242] ? devres_remove_group+0x1b0/0x1b0 [ 2489.637247] device_release_driver_internal+0x146/0x270 [ 2489.637251] driver_detach+0x73/0xe0 [ 2489.637254] bus_remove_driver+0xa1/0x170 [ 2489.637261] __x64_sys_delete_module+0x29e/0x320 [ 2489.637265] ? __ia32_sys_delete_module+0x320/0x320 [ 2489.637268] ? blkcg_exit_queue+0x20/0x20 [ 2489.637273] ? task_work_run+0x7d/0x100 [ 2489.637278] ? exit_to_usermode_loop+0x5b/0xf0 [ 2489.637281] do_syscall_64+0x73/0x160 [ 2489.637287] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 2489.637290] RIP: 0033:0x7f95c3596fd7
The difference in release flow with and with no devm_free_irq is listed below:
bus: 'platform': remove driver mlxreg-hotplug mlxreg_hotplug_remove(start) -> devm_free_irq (with new code) mlxreg_hotplug_remove (end) release_nodes (start) mlxreg-hotplug: DEVRES REL devm_hwmon_release (8 bytes) device: 'hwmon3': device_unregister PM: Removing info for No Bus:hwmon3 mlxreg-hotplug: DEVRES REL devm_kzalloc_release (88 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (6 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (5 bytes) mlxreg-hotplug: DEVRES REL devm_irq_release (16 bytes) (no new code) mlxreg-hotplug: DEVRES REL devm_kzalloc_release (1376 bytes) ------------[ cut here ]------------ (no new code): ODEBUG: free active (active state 0) object type: work_struct hint: mlxreg_hotplug_work_handler
release_nodes(end) driver: 'mlxreg-hotplug': driver_release
Fixes: 1f976f6978bf ("platform/x86: Move Mellanox platform hotplug driver to platform/mellanox") Signed-off-by: Vadim Pasternak vadimp@mellanox.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/mellanox/mlxreg-hotplug.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/platform/mellanox/mlxreg-hotplug.c b/drivers/platform/mellanox/mlxreg-hotplug.c index eca16d00e310..d52c821b8584 100644 --- a/drivers/platform/mellanox/mlxreg-hotplug.c +++ b/drivers/platform/mellanox/mlxreg-hotplug.c @@ -673,6 +673,7 @@ static int mlxreg_hotplug_remove(struct platform_device *pdev)
/* Clean interrupts setup. */ mlxreg_hotplug_unset_irq(priv); + devm_free_irq(&pdev->dev, priv->irq, priv);
return 0; }