8c2eb7b646
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:
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| .. | ||
| chrome | ||
| goldfish | ||
| mellanox | ||
| mips | ||
| olpc | ||
| x86 | ||
| Kconfig | ||
| Makefile | ||