linux-stable.git/drivers/base/power/runtime.c, branch linux-5.15.y

PM: runtime: Fix a race condition related to device removal

2026-04-18T08:33:21+00:00

[ Upstream commit 29ab768277617452d88c0607c9299cdc63b6e9ff ]

The following code in pm_runtime_work() may dereference the dev->parent
pointer after the parent device has been freed:

	/* Maybe the parent is now able to suspend. */
	if (parent && !parent->power.ignore_children) {
		spin_unlock(&dev->power.lock);

		spin_lock(&parent->power.lock);
		rpm_idle(parent, RPM_ASYNC);
		spin_unlock(&parent->power.lock);

		spin_lock(&dev->power.lock);
	}

Fix this by inserting a flush_work() call in pm_runtime_remove().

Without this patch blktest block/001 triggers the following complaint
sporadically:

BUG: KASAN: slab-use-after-free in lock_acquire+0x70/0x160
Read of size 1 at addr ffff88812bef7198 by task kworker/u553:1/3081
Workqueue: pm pm_runtime_work
Call Trace:
 
 dump_stack_lvl+0x61/0x80
 print_address_description.constprop.0+0x8b/0x310
 print_report+0xfd/0x1d7
 kasan_report+0xd8/0x1d0
 __kasan_check_byte+0x42/0x60
 lock_acquire.part.0+0x38/0x230
 lock_acquire+0x70/0x160
 _raw_spin_lock+0x36/0x50
 rpm_suspend+0xc6a/0xfe0
 rpm_idle+0x578/0x770
 pm_runtime_work+0xee/0x120
 process_one_work+0xde3/0x1410
 worker_thread+0x5eb/0xfe0
 kthread+0x37b/0x480
 ret_from_fork+0x6cb/0x920
 ret_from_fork_asm+0x11/0x20
 

Allocated by task 4314:
 kasan_save_stack+0x2a/0x50
 kasan_save_track+0x18/0x40
 kasan_save_alloc_info+0x3d/0x50
 __kasan_kmalloc+0xa0/0xb0
 __kmalloc_noprof+0x311/0x990
 scsi_alloc_target+0x122/0xb60 [scsi_mod]
 __scsi_scan_target+0x101/0x460 [scsi_mod]
 scsi_scan_channel+0x179/0x1c0 [scsi_mod]
 scsi_scan_host_selected+0x259/0x2d0 [scsi_mod]
 store_scan+0x2d2/0x390 [scsi_mod]
 dev_attr_store+0x43/0x80
 sysfs_kf_write+0xde/0x140
 kernfs_fop_write_iter+0x3ef/0x670
 vfs_write+0x506/0x1470
 ksys_write+0xfd/0x230
 __x64_sys_write+0x76/0xc0
 x64_sys_call+0x213/0x1810
 do_syscall_64+0xee/0xfc0
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Freed by task 4314:
 kasan_save_stack+0x2a/0x50
 kasan_save_track+0x18/0x40
 kasan_save_free_info+0x3f/0x50
 __kasan_slab_free+0x67/0x80
 kfree+0x225/0x6c0
 scsi_target_dev_release+0x3d/0x60 [scsi_mod]
 device_release+0xa3/0x220
 kobject_cleanup+0x105/0x3a0
 kobject_put+0x72/0xd0
 put_device+0x17/0x20
 scsi_device_dev_release+0xacf/0x12c0 [scsi_mod]
 device_release+0xa3/0x220
 kobject_cleanup+0x105/0x3a0
 kobject_put+0x72/0xd0
 put_device+0x17/0x20
 scsi_device_put+0x7f/0xc0 [scsi_mod]
 sdev_store_delete+0xa5/0x120 [scsi_mod]
 dev_attr_store+0x43/0x80
 sysfs_kf_write+0xde/0x140
 kernfs_fop_write_iter+0x3ef/0x670
 vfs_write+0x506/0x1470
 ksys_write+0xfd/0x230
 __x64_sys_write+0x76/0xc0
 x64_sys_call+0x213/0x1810

Reported-by: Ming Lei 
Closes: https://lore.kernel.org/all/ZxdNvLNI8QaOfD2d@fedora/
Reported-by: syzbot+6c905ab800f20cf4086c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68c13942.050a0220.2ff435.000b.GAE@google.com/
Fixes: 5e928f77a09a ("PM: Introduce core framework for run-time PM of I/O devices (rev. 17)")
Signed-off-by: Bart Van Assche 
Link: https://patch.msgid.link/20260312182720.2776083-1-bvanassche@acm.org
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: runtime: Do not clear needs_force_resume with enabled runtime PM

2026-01-19T12:09:53+00:00

commit 359afc8eb02a518fbdd0cbd462c8c2827c6cbec2 upstream.

Commit 89d9cec3b1e9 ("PM: runtime: Clear power.needs_force_resume in
pm_runtime_reinit()") added provisional clearing of power.needs_force_resume
to pm_runtime_reinit(), but it is done unconditionally which is a
mistake because pm_runtime_reinit() may race with driver probing
and removal [1].

To address this, notice that power.needs_force_resume should never
be set when runtime PM is enabled and so it only needs to be cleared
when runtime PM is disabled, and update pm_runtime_init() to only
clear that flag when runtime PM is disabled.

Fixes: 89d9cec3b1e9 ("PM: runtime: Clear power.needs_force_resume in pm_runtime_reinit()")
Reported-by: Ed Tsai 
Closes: https://lore.kernel.org/linux-pm/20251215122154.3180001-1-ed.tsai@mediatek.com/ [1]
Signed-off-by: Rafael J. Wysocki 
Cc: 6.17+  # 6.17+
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/12807571.O9o76ZdvQC@rafael.j.wysocki
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Add new devm functions

2025-10-29T13:03:14+00:00

[ Upstream commit 73db799bf5efc5a04654bb3ff6c9bf63a0dfa473 ]

Add `devm_pm_runtime_set_active_enabled()` and
`devm_pm_runtime_get_noresume()` for simplifying
common cases in drivers.

Signed-off-by: Bence Csókás 
Link: https://patch.msgid.link/20250327195928.680771-3-csokas.bence@prolan.hu
Signed-off-by: Rafael J. Wysocki 
Stable-dep-of: 0792c1984a45 ("iio: imu: inv_icm42600: Simplify pm_runtime setup")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Clear power.needs_force_resume in pm_runtime_reinit()

2025-08-28T14:24:18+00:00

[ Upstream commit 89d9cec3b1e9c49bae9375a2db6dc49bc7468af0 ]

Clear power.needs_force_resume in pm_runtime_reinit() in case it has
been set by pm_runtime_force_suspend() invoked from a driver remove
callback.

Suggested-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/9495163.CDJkKcVGEf@rjwysocki.net
Signed-off-by: Sasha Levin

PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()

2025-06-27T10:05:28+00:00

[ Upstream commit 40d3b40dce375d6f1c1dbf08d79eed3aed6c691d ]

pm_runtime_put_autosuspend() schedules a hrtimer to expire
at "dev->power.timer_expires". If the hrtimer's callback,
pm_suspend_timer_fn(), observes that the current time equals
"dev->power.timer_expires", it unexpectedly bails out instead of
proceeding with runtime suspend.

pm_suspend_timer_fn():

 if (expires > 0 && expires < ktime_get_mono_fast_ns()) {
 	dev->power.timer_expires = 0;
 	rpm_suspend(..)
 }

Additionally, as ->timer_expires is not cleared, all the future auto
suspend requests will not schedule hrtimer to perform auto suspend.

rpm_suspend():

 if ((rpmflags & RPM_AUTO) &&...) {
 	if (!(dev->power.timer_expires && ...) { <-- this will fail.
 		hrtimer_start_range_ns(&dev->power.suspend_timer,...);
 	}
 }

Fix this by as well checking if current time reaches the set expiration.

Co-developed-by: Patrick Daly 
Signed-off-by: Patrick Daly 
Signed-off-by: Charan Teja Kalla 
Link: https://patch.msgid.link/20250515064125.1211561-1-quic_charante@quicinc.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: sleep: Adjust check before setting power.must_resume

2025-04-10T12:31:57+00:00

[ Upstream commit eeb87d17aceab7803a5a5bcb6cf2817b745157cf ]

The check before setting power.must_resume in device_suspend_noirq()
does not take power.child_count into account, but it should do that, so
use pm_runtime_need_not_resume() in it for this purpose and adjust the
comment next to it accordingly.

Fixes: 107d47b2b95e ("PM: sleep: core: Simplify the SMART_SUSPEND flag handling")
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/3353728.44csPzL39Z@rjwysocki.net
Signed-off-by: Sasha Levin

PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend()

2024-02-23T07:55:15+00:00

[ Upstream commit b4060db9251f919506e4d672737c6b8ab9a84701 ]

The PM Runtime docs say:

  Drivers in ->remove() callback should undo the runtime PM changes done
  in ->probe(). Usually this means calling pm_runtime_disable(),
  pm_runtime_dont_use_autosuspend() etc.

>From grepping code, it's clear that many people aren't aware of the
need to call pm_runtime_dont_use_autosuspend().

When brainstorming solutions, one idea that came up was to leverage
the new-ish devm_pm_runtime_enable() function. The idea here is that:

 * When the devm action is called we know that the driver is being
   removed. It's the perfect time to undo the use_autosuspend.

 * The code of pm_runtime_dont_use_autosuspend() already handles the
   case of being called when autosuspend wasn't enabled.

Suggested-by: Laurent Pinchart 
Signed-off-by: Douglas Anderson 
Reviewed-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki 
Stable-dep-of: 3d07a411b4fa ("drm/msm/dsi: Use pm_runtime_resume_and_get to prevent refcnt leaks")
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

PM / wakeirq: support enabling wake-up irq after runtime_suspend called

2023-08-11T13:14:00+00:00

[ Upstream commit 259714100d98b50bf04d36a21bf50ca8b829fc11 ]

When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's ->runtime_suspend() which make it enter low-power state.

e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.

                ------------------
               |           ^     ^|
----------------           |     | --------------
 |<---(0)--->|<--(1)--|   (3)   (2)    (4)

if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
->runtime_suspend().

This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running ->runtime_suspend().

Suggested-by: Rafael J. Wysocki 
Signed-off-by: Chunfeng Yun 
Signed-off-by: Rafael J. Wysocki 
Stable-dep-of: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming")
Signed-off-by: Sasha Levin

PM: runtime: Do not call __rpm_callback() from rpm_idle()

2022-12-31T12:14:04+00:00

[ Upstream commit bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88 ]

Calling __rpm_callback() from rpm_idle() after adding device links
support to the former is a clear mistake.

Not only it causes rpm_idle() to carry out unnecessary actions, but it
is also against the assumption regarding the stability of PM-runtime
status across __rpm_callback() invocations, because rpm_suspend() and
rpm_resume() may run in parallel with __rpm_callback() when it is called
by rpm_idle() and the device's PM-runtime status can be updated by any
of them.

Fixes: 21d5c57b3726 ("PM / runtime: Use device links")
Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Adrian Hunter 
Signed-off-by: Sasha Levin

PM: runtime: Redefine pm_runtime_release_supplier()

2022-07-12T14:35:09+00:00

commit 07358194badf73e267289b40b761f5dc56928eab upstream.

Instead of passing an extra bool argument to pm_runtime_release_supplier(),
make its callers take care of triggering a runtime-suspend of the
supplier device as needed.

No expected functional impact.

Suggested-by: Greg Kroah-Hartman 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Greg Kroah-Hartman 
Cc: 5.1+  # 5.1+
Signed-off-by: Greg Kroah-Hartman