[PATCH v2 4/4] thermal/of: Fix free after use in thermal_of_unregister()
From: Daniel Lezcano
Date: Tue Aug 09 2022 - 04:57:05 EST
The thermal zone is freed after being unregistered. The release method
devm_thermal_zone_device_register() calls
-> thermal_of_zone_device_unregister()
This one calls thermal_zone_device_unregister() which frees the
thermal zone. However, thermal_of_zone_device_unregister() does access
this freed pointer to free different resources allocated by the
thermal_of framework which is invalid.
It results in a kernel panic:
[ 1.915140] thermal_sys: Failed to find thermal zone for tmu id=2
[ 1.921279] qoriq_thermal 1f80000.tmu: Failed to register sensors
[ 1.927395] qoriq_thermal: probe of 1f80000.tmu failed with error -22
[ 1.934189] Unable to handle kernel paging request at virtual address 01adadadadadad88
[ 1.942146] Mem abort info:
[ 1.944948] ESR = 0x0000000096000004
[ 1.948708] EC = 0x25: DABT (current EL), IL = 32 bits
[ 1.954042] SET = 0, FnV = 0
[ 1.957107] EA = 0, S1PTW = 0
[ 1.960253] FSC = 0x04: level 0 translation fault
[ 1.965147] Data abort info:
[ 1.968030] ISV = 0, ISS = 0x00000004
[ 1.971878] CM = 0, WnR = 0
[ 1.974852] [01adadadadadad88] address between user and kernel address ranges
[ 1.982016] Internal error: Oops: 96000004 [#1] SMP
[ 1.986907] Modules linked in:
[ 1.989969] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-next-20220808-00080-g1c46f44502e0 #1697
[ 1.999135] Hardware name: Kontron KBox A-230-LS (DT)
[ 2.004199] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 2.011185] pc : kfree+0x5c/0x3c0
[ 2.014516] lr : devm_thermal_of_zone_release+0x38/0x60
[ 2.019761] sp : ffff80000a22bad0
[ 2.023081] x29: ffff80000a22bad0 x28: 0000000000000000 x27: ffff800009960464
[ 2.030245] x26: ffff800009a16960 x25: 0000000000000006 x24: ffff800009f09a40
[ 2.037407] x23: ffff800009ab9008 x22: ffff800008d0eea8 x21: 01adadadadadad80
[ 2.044569] x20: 6b6b6b6b6b6b6b6b x19: ffff00200232b800 x18: 00000000fffffffb
[ 2.051731] x17: ffff800008d0eea0 x16: ffff800008d07d44 x15: ffff800008d0d154
[ 2.056647] usb 1-1: new high-speed USB device number 2 using xhci-hcd
[ 2.058893] x14: ffff800008d0cddc x13: ffff8000088d1c2c x12: ffff8000088d5034
[ 2.072597] x11: ffff8000088d46d4 x10: 0000000000000000 x9 : ffff800008d0eea8
[ 2.079759] x8 : ffff002000b1a158 x7 : bbbbbbbbbbbbbbbb x6 : ffff80000a0f53b8
[ 2.086921] x5 : ffff80000a22b960 x4 : 0000000000000000 x3 : 0000000000000000
[ 2.094082] x2 : fffffc0000000000 x1 : ffff002000838040 x0 : 01adb1adadadad80
[ 2.101244] Call trace:
[ 2.103692] kfree+0x5c/0x3c0
[ 2.106666] devm_thermal_of_zone_release+0x38/0x60
[ 2.111561] release_nodes+0x64/0xd0
[ 2.115146] devres_release_all+0xbc/0x350
[ 2.119253] device_unbind_cleanup+0x20/0x70
[ 2.123536] really_probe+0x1a0/0x2e4
[ 2.127208] __driver_probe_device+0x80/0xec
[ 2.131490] driver_probe_device+0x44/0x130
[ 2.135685] __driver_attach+0x104/0x1b4
[ 2.139619] bus_for_each_dev+0x7c/0xe0
[ 2.143465] driver_attach+0x30/0x40
[ 2.147048] bus_add_driver+0x160/0x210
[ 2.150894] driver_register+0x84/0x140
[ 2.154741] __platform_driver_register+0x34/0x40
[ 2.159461] qoriq_tmu_init+0x28/0x34
[ 2.163133] do_one_initcall+0x50/0x250
[ 2.166979] kernel_init_freeable+0x278/0x31c
[ 2.171349] kernel_init+0x30/0x140
[ 2.174847] ret_from_fork+0x10/0x20
[ 2.178433] Code: b25657e2 d34cfc00 d37ae400 8b020015 (f94006a1)
[ 2.184546] ---[ end trace 0000000000000000 ]---
Store the allocated resource pointers before the thermal zone is free
and use them to release the resource after unregistering the thermal
zone.
Reported-by: Michael Walle <michael@xxxxxxxx>
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Tested-by: Michael Walle <michael@xxxxxxxx>
---
drivers/thermal/thermal_of.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
index 3effc729be4b..fd2fb84bf246 100644
--- a/drivers/thermal/thermal_of.c
+++ b/drivers/thermal/thermal_of.c
@@ -596,11 +596,15 @@ static int thermal_of_unbind(struct thermal_zone_device *tz,
*/
void thermal_of_zone_unregister(struct thermal_zone_device *tz)
{
+ struct thermal_trip *trips = tz->trips;
+ struct thermal_zone_params *tzp = tz->tzp;
+ struct thermal_zone_device_ops *ops = tz->ops;
+
thermal_zone_device_disable(tz);
thermal_zone_device_unregister(tz);
- kfree(tz->trips);
- kfree(tz->tzp);
- kfree(tz->ops);
+ kfree(trips);
+ kfree(tzp);
+ kfree(ops);
}
EXPORT_SYMBOL_GPL(thermal_of_zone_unregister);
--
2.34.1