hwmon: (core) Fix double-free in __hwmon_device_register()

digetx · gregkh · commit ffea8daac4c5 · 2020-01-29T15:02:37.000+01:00
commit 74e3512 upstream. Fix double-free that happens when thermal zone setup fails, see KASAN log below. ================================================================== BUG: KASAN: double-free or invalid-free in __hwmon_device_register+0x5dc/0xa7c CPU: 0 PID: 132 Comm: kworker/0:2 Tainted: G B 4.19.0-rc8-next-20181016-00042-gb52cd80401e9-dirty #41 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) Workqueue: events deferred_probe_work_func Backtrace: [<c0110540>] (dump_backtrace) from [<c0110944>] (show_stack+0x20/0x24) [<c0110924>] (show_stack) from [<c105cb08>] (dump_stack+0x9c/0xb0) [<c105ca6c>] (dump_stack) from [<c02fdaec>] (print_address_description+0x68/0x250) [<c02fda84>] (print_address_description) from [<c02fd4ac>] (kasan_report_invalid_free+0x68/0x88) [<c02fd444>] (kasan_report_invalid_free) from [<c02fc85c>] (__kasan_slab_free+0x1f4/0x200) [<c02fc668>] (__kasan_slab_free) from [<c02fd0c0>] (kasan_slab_free+0x14/0x18) [<c02fd0ac>] (kasan_slab_free) from [<c02f9c6c>] (kfree+0x90/0x294) [<c02f9bdc>] (kfree) from [<c0b41bbc>] (__hwmon_device_register+0x5dc/0xa7c) [<c0b415e0>] (__hwmon_device_register) from [<c0b421e8>] (hwmon_device_register_with_info+0xa0/0xa8) [<c0b42148>] (hwmon_device_register_with_info) from [<c0b42324>] (devm_hwmon_device_register_with_info+0x74/0xb4) [<c0b422b0>] (devm_hwmon_device_register_with_info) from [<c0b4481c>] (lm90_probe+0x414/0x578) [<c0b44408>] (lm90_probe) from [<c0aeeff4>] (i2c_device_probe+0x35c/0x384) [<c0aeec98>] (i2c_device_probe) from [<c08776cc>] (really_probe+0x290/0x3e4) [<c087743c>] (really_probe) from [<c0877a2c>] (driver_probe_device+0x80/0x1c4) [<c08779ac>] (driver_probe_device) from [<c0877da8>] (__device_attach_driver+0x104/0x11c) [<c0877ca4>] (__device_attach_driver) from [<c0874dd8>] (bus_for_each_drv+0xa4/0xc8) [<c0874d34>] (bus_for_each_drv) from [<c08773b0>] (__device_attach+0xf0/0x15c) [<c08772c0>] (__device_attach) from [<c0877e24>] (device_initial_probe+0x1c/0x20) [<c0877e08>] (device_initial_probe) from [<c08762f4>] (bus_probe_device+0xdc/0xec) [<c0876218>] (bus_probe_device) from [<c0876a08>] (deferred_probe_work_func+0xa8/0xd4) [<c0876960>] (deferred_probe_work_func) from [<c01527c4>] (process_one_work+0x3dc/0x96c) [<c01523e8>] (process_one_work) from [<c01541e0>] (worker_thread+0x4ec/0x8bc) [<c0153cf4>] (worker_thread) from [<c015b238>] (kthread+0x230/0x240) [<c015b008>] (kthread) from [<c01010bc>] (ret_from_fork+0x14/0x38) Exception stack(0xcf743fb0 to 0xcf743ff8) 3fa0: 00000000 00000000 00000000 00000000 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 Allocated by task 132: kasan_kmalloc.part.1+0x58/0xf4 kasan_kmalloc+0x90/0xa4 kmem_cache_alloc_trace+0x90/0x2a0 __hwmon_device_register+0xbc/0xa7c hwmon_device_register_with_info+0xa0/0xa8 devm_hwmon_device_register_with_info+0x74/0xb4 lm90_probe+0x414/0x578 i2c_device_probe+0x35c/0x384 really_probe+0x290/0x3e4 driver_probe_device+0x80/0x1c4 __device_attach_driver+0x104/0x11c bus_for_each_drv+0xa4/0xc8 __device_attach+0xf0/0x15c device_initial_probe+0x1c/0x20 bus_probe_device+0xdc/0xec deferred_probe_work_func+0xa8/0xd4 process_one_work+0x3dc/0x96c worker_thread+0x4ec/0x8bc kthread+0x230/0x240 ret_from_fork+0x14/0x38 (null) Freed by task 132: __kasan_slab_free+0x12c/0x200 kasan_slab_free+0x14/0x18 kfree+0x90/0x294 hwmon_dev_release+0x1c/0x20 device_release+0x4c/0xe8 kobject_put+0xac/0x11c device_unregister+0x2c/0x30 __hwmon_device_register+0xa58/0xa7c hwmon_device_register_with_info+0xa0/0xa8 devm_hwmon_device_register_with_info+0x74/0xb4 lm90_probe+0x414/0x578 i2c_device_probe+0x35c/0x384 really_probe+0x290/0x3e4 driver_probe_device+0x80/0x1c4 __device_attach_driver+0x104/0x11c bus_for_each_drv+0xa4/0xc8 __device_attach+0xf0/0x15c device_initial_probe+0x1c/0x20 bus_probe_device+0xdc/0xec deferred_probe_work_func+0xa8/0xd4 process_one_work+0x3dc/0x96c worker_thread+0x4ec/0x8bc kthread+0x230/0x240 ret_from_fork+0x14/0x38 (null) Cc: <stable@vger.kernel.org> # v4.15+ Fixes: 47c332d ("hwmon: Deal with errors from the thermal subsystem") Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
@@ -631,17 +631,17 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
 				if (info[i]->config[j] & HWMON_T_INPUT) {
 					err = hwmon_thermal_add_sensor(dev,
 								hwdev, j);
-					if (err)
-						goto free_device;
+					if (err) {
+						device_unregister(hdev);
+						goto ida_remove;
+					}
 				}
 			}
 		}
 	}
 
 	return hdev;
 
-free_device:
-	device_unregister(hdev);
 free_hwmon:
 	kfree(hwdev);
 ida_remove:

Original file line number	Diff line number	Diff line change
`@@ -631,17 +631,17 @@ __hwmon_device_register(struct device dev, const char name, void *drvdata,`
`631`	`631`	`if (info[i]->config[j] & HWMON_T_INPUT) {`
`632`	`632`	`err = hwmon_thermal_add_sensor(dev,`
`633`	`633`	`hwdev, j);`
`634`		`- if (err)`
`635`		`- goto free_device;`
	`634`	`+ if (err) {`
	`635`	`+ device_unregister(hdev);`
	`636`	`+ goto ida_remove;`
	`637`	`+ }`
`636`	`638`	`}`
`637`	`639`	`}`
`638`	`640`	`}`
`639`	`641`	`}`
`640`	`642`
`641`	`643`	`return hdev;`
`642`	`644`
`643`		`-free_device:`
`644`		`- device_unregister(hdev);`
`645`	`645`	`free_hwmon:`
`646`	`646`	`kfree(hwdev);`
`647`	`647`	`ida_remove:`