On 11/5/21 9:37 AM, Rafael J. Wysocki wrote: > On Fri, Nov 5, 2021 at 5:19 PM Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: >> On 05/11/2021 16:14, Rafael J. Wysocki wrote: >>> On Fri, Nov 5, 2021 at 12:57 AM Subbaraman Narayanamurthy >>> <quic_subbaram@xxxxxxxxxxx> 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(). >>> Can the subject be more specific, please? >>> >>> The issue appears to be limited to the of_thermal_ family of >>> functions, but the subject doesn't reflect that at all. >>> >>>> Suggested-by: David Collins <quic_collinsd@xxxxxxxxxxx> >>>> Signed-off-by: Subbaraman Narayanamurthy <quic_subbaram@xxxxxxxxxxx> >>> Daniel, any concerns regarding the code changes below? >> I've a concern about the root cause but I did not have time to >> investigate how to fix it nicely. >> >> thermal_of is responsible of introducing itself between the thermal core >> code and the backend. So it defines the ops which in turn call the >> sensor ops leading us to this problem. >> >> So, without a better solution, this fix can be applied until we rethink >> the thermal_of approach. >> >> Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> > Thanks! > > I've queued it up for 5.16-rc as "thermal: Fix NULL pointer > dereferences in of_thermal_ functions". Thanks, Daniel and Rafael. So, I guess I don't need to send v3 with fixing commit subject right? -Subbaraman
