Re: [RESEND PATCH v2] thermal: Fix a NULL pointer dereference

From: Subbaraman Narayanamurthy
Date: Fri Nov 05 2021 - 16:06:22 EST


On 11/4/21 11:50 PM, Greg KH wrote:
> On Thu, Nov 04, 2021 at 04:57:07PM -0700, Subbaraman Narayanamurthy wrote:
>> of_parse_thermal_zones() parses the thermal-zones node and registers a
>> thermal_zone device for each subnode. However, if a thermal zone is
>> consuming a thermal sensor and that thermal sensor device hasn't probed
>> yet, an attempt to set trip_point_*_temp for that thermal zone device
>> can cause a NULL pointer dereference. Fix it.
>>
>> console:/sys/class/thermal/thermal_zone87 # echo 120000 > trip_point_0_temp
>> ...
>> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
>> ...
>> Call trace:
>> of_thermal_set_trip_temp+0x40/0xc4
>> trip_point_temp_store+0xc0/0x1dc
>> dev_attr_store+0x38/0x88
>> sysfs_kf_write+0x64/0xc0
>> kernfs_fop_write_iter+0x108/0x1d0
>> vfs_write+0x2f4/0x368
>> ksys_write+0x7c/0xec
>> __arm64_sys_write+0x20/0x30
>> el0_svc_common.llvm.7279915941325364641+0xbc/0x1bc
>> do_el0_svc+0x28/0xa0
>> el0_svc+0x14/0x24
>> el0_sync_handler+0x88/0xec
>> el0_sync+0x1c0/0x200
>>
>> While at it, fix the possible NULL pointer dereference in other
>> functions as well: of_thermal_get_temp(), of_thermal_set_emul_temp(),
>> of_thermal_get_trend().
>>
>> Suggested-by: David Collins <quic_collinsd@xxxxxxxxxxx>
>> Signed-off-by: Subbaraman Narayanamurthy <quic_subbaram@xxxxxxxxxxx>
>> ---
>> drivers/thermal/thermal_of.c | 9 ++++++---
>> 1 file changed, 6 insertions(+), 3 deletions(-)
>>
> <formletter>
>
> This is not the correct way to submit patches for inclusion in the
> stable kernel tree. Please read:
> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> for how to do this properly.
>
> </formletter>

Hi Greg,
For this case, is it because I've missed adding "Cc:stable@xxxxxxxxxxxxxxx" in commit text itself and cc-ed stable@xxxxxxxxxxxxxxx directly?

Thanks,
Subbaraman