kernel/linux.git/drivers/base/power, branch v6.6.131

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

2026-03-25T10:06:07+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: sleep: wakeirq: harden dev_pm_clear_wake_irq() against races

2026-03-04T12:19:29+00:00

[ Upstream commit 5c9ecd8e6437cd55a38ea4f1e1d19cee8e226cb8 ] dev_pm_clear_wake_irq() currently uses a dangerous pattern where dev->power.wakeirq is read and checked for NULL outside the lock. If two callers invoke this function concurrently, both might see a valid pointer and proceed. This could result in a double-free when the second caller acquires the lock and tries to release the same object. Address this by removing the lockless check of dev->power.wakeirq. Instead, acquire dev->power.lock immediately to ensure the check and the subsequent operations are atomic. If dev->power.wakeirq is NULL under the lock, simply unlock and return. This guarantees that concurrent calls cannot race to free the same object. Based on a quick scan of current users, I did not find an actual bug as drivers seem to rely on their own synchronization. However, since asynchronous usage patterns exist (e.g., in drivers/net/wireless/ti/wlcore), I believe a race is theoretically possible if the API is used less carefully in the future. This change hardens the API to be robust against such cases. Fixes: 4990d4fe327b ("PM / Wakeirq: Add automated device wake IRQ handling") Signed-off-by: Gui-Dong Han Link: https://patch.msgid.link/20260203031943.1924-1-hanguidong02@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM: wakeup: Handle empty list in wakeup_sources_walk_start()

2026-03-04T12:19:29+00:00

[ Upstream commit 75ce02f4bc9a8b8350b6b1b01872467b0cc960cc ] In the case of an empty wakeup_sources list, wakeup_sources_walk_start() will return an invalid but non-NULL address. This also affects wrappers of the aforementioned function, like for_each_wakeup_source(). Update wakeup_sources_walk_start() to return NULL in case of an empty list. Fixes: b4941adb24c0 ("PM: wakeup: Add routine to help fetch wakeup source object.") Signed-off-by: Samuel Wu [ rjw: Subject and changelog edits ] Link: https://patch.msgid.link/20260124012133.2451708-2-wusamuel@google.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

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

2026-01-11T14:22:01+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

2025-10-23T14:16:39+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: sleep: core: Clear power.must_resume in noirq suspend error path

2025-10-15T09:57:51+00:00

[ Upstream commit be82483d1b60baf6747884bd74cb7de484deaf76 ] If system suspend is aborted in the "noirq" phase (for instance, due to an error returned by one of the device callbacks), power.is_noirq_suspended will not be set for some devices and device_resume_noirq() will return early for them. Consequently, noirq resume callbacks will not run for them at all because the noirq suspend callbacks have not run for them yet. If any of them has power.must_resume set and late suspend has been skipped for it (due to power.smart_suspend), early resume should be skipped for it either, or its state may become inconsistent (for instance, if the early resume assumes that it will always follow noirq resume). Make that happen by clearing power.must_resume in device_resume_noirq() for devices with power.is_noirq_suspended clear that have been left in suspend by device_suspend_late(), which will subsequently cause device_resume_early() to leave the device in suspend and avoid changing its state. Fixes: 0d4b54c6fee8 ("PM / core: Add LEAVE_SUSPENDED driver flag") Link: https://lore.kernel.org/linux-pm/5d692b81-6f58-4e86-9cb0-ede69a09d799@rowland.harvard.edu/ Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/3381776.aeNJFYEL58@rafael.j.wysocki Signed-off-by: Sasha Levin

PM: runtime: Take active children into account in pm_runtime_get_if_in_use()

2025-08-28T14:28:42+00:00

[ Upstream commit 51888393cc64dd0462d0b96c13ab94873abbc030 ] For all practical purposes, there is no difference between the situation in which a given device is not ignoring children and its active child count is nonzero and the situation in which its runtime PM usage counter is nonzero. However, pm_runtime_get_if_in_use() will only increment the device's usage counter and return 1 in the latter case. For consistency, make it do so in the former case either by adjusting pm_runtime_get_conditional() and update the related kerneldoc comments accordingly. Fixes: c111566bea7c ("PM: runtime: Add pm_runtime_get_if_active()") Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Sakari Ailus Cc: 5.10+ # 5.10+: c0ef3df8dbae: PM: runtime: Simplify pm_runtime_get_if_active() usage Cc: 5.10+ # 5.10+ Link: https://patch.msgid.link/12700973.O9o76ZdvQC@rjwysocki.net Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PM: runtime: Simplify pm_runtime_get_if_active() usage

2025-08-28T14:28:42+00:00

[ Upstream commit c0ef3df8dbaef51ee4cfd58a471adf2eaee6f6b3 ] There are two ways to opportunistically increment a device's runtime PM usage count, calling either pm_runtime_get_if_active() or pm_runtime_get_if_in_use(). The former has an argument to tell whether to ignore the usage count or not, and the latter simply calls the former with ign_usage_count set to false. The other users that want to ignore the usage_count will have to explicitly set that argument to true which is a bit cumbersome. To make this function more practical to use, remove the ign_usage_count argument from the function. The main implementation is in a static function called pm_runtime_get_conditional() and implementations of pm_runtime_get_if_active() and pm_runtime_get_if_in_use() are moved to runtime.c. Signed-off-by: Sakari Ailus Reviewed-by: Alex Elder Reviewed-by: Laurent Pinchart Acked-by: Takashi Iwai # sound/ Reviewed-by: Jacek Lawrynowicz # drivers/accel/ivpu/ Acked-by: Rodrigo Vivi # drivers/gpu/drm/i915/ Reviewed-by: Rodrigo Vivi Acked-by: Bjorn Helgaas # drivers/pci/ Signed-off-by: Rafael J. Wysocki [ Removed changes to code that didn't exist in older trees ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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

2025-08-28T14:28:17+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

pmdomain: governor: Consider CPU latency tolerance from pm_domain_cpu_gov

2025-07-24T06:53:14+00:00

commit 500ba33284416255b9a5b50ace24470b6fe77ea5 upstream. pm_domain_cpu_gov is selecting a cluster idle state but does not consider latency tolerance of child CPUs. This results in deeper cluster idle state whose latency does not meet latency tolerance requirement. Select deeper idle state only if global and device latency tolerance of all child CPUs meet. Test results on SM8750 with 300 usec PM-QoS on CPU0 which is less than domain idle state entry (2150) + exit (1983) usec latency mentioned in devicetree, demonstrate the issue. # echo 300 > /sys/devices/system/cpu/cpu0/power/pm_qos_resume_latency_us Before: (Usage is incrementing) ====== # cat /sys/kernel/debug/pm_genpd/power-domain-cluster0/idle_states State Time Spent(ms) Usage Rejected Above Below S0 29817 537 8 270 0 # cat /sys/kernel/debug/pm_genpd/power-domain-cluster0/idle_states State Time Spent(ms) Usage Rejected Above Below S0 30348 542 8 271 0 After: (Usage is not incrementing due to latency tolerance) ====== # cat /sys/kernel/debug/pm_genpd/power-domain-cluster0/idle_states State Time Spent(ms) Usage Rejected Above Below S0 39319 626 14 307 0 # cat /sys/kernel/debug/pm_genpd/power-domain-cluster0/idle_states State Time Spent(ms) Usage Rejected Above Below S0 39319 626 14 307 0 Signed-off-by: Maulik Shah Fixes: e94999688e3a ("PM / Domains: Add genpd governor for CPUs") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250709-pmdomain_qos-v2-1-976b12257899@oss.qualcomm.com Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman