commit 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 upstream.
It is incorrect to set the cpufreq syscore shutdown callback pointer
to cpufreq_suspend(), because that function cannot be run in the
syscore stage of system shutdown for two reasons: (a) it may attempt
to carry out actions depending on devices that have already been shut
down at that point and (b) the RCU synchronization carried out by it
may not be able to make progress then.
The latter issue has been present since commit 45975c7d21a1 ("rcu:
Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"),
but the former one has been there since commit 90de2a4aa9f3 ("cpufreq:
suspend cpufreq governors on shutdown") regardless.
Fix that by dropping cpufreq_syscore_ops altogether and making
device_shutdown() call cpufreq_suspend() directly before shutting
down devices, which is along the lines of what system-wide power
management does.
Fixes: 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds")
Fixes: 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ac43432cb1f5c2950408534987e57c2071e24d8f upstream.
There is a race condition between removing glue directory and adding a new
device under the glue dir. It can be reproduced in following test:
CPU1: CPU2:
device_add()
get_device_parent()
class_dir_create_and_add()
kobject_add_internal()
create_dir() // create glue_dir
device_add()
get_device_parent()
kobject_get() // get glue_dir
device_del()
cleanup_glue_dir()
kobject_del(glue_dir)
kobject_add()
kobject_add_internal()
create_dir() // in glue_dir
sysfs_create_dir_ns()
kernfs_create_dir_ns(sd)
sysfs_remove_dir() // glue_dir->sd=NULL
sysfs_put() // free glue_dir->sd
// sd is freed
kernfs_new_node(sd)
kernfs_get(glue_dir)
kernfs_add_one()
kernfs_put()
Before CPU1 remove last child device under glue dir, if CPU2 add a new
device under glue dir, the glue_dir kobject reference count will be
increase to 2 via kobject_get() in get_device_parent(). And CPU2 has
been called kernfs_create_dir_ns(), but not call kernfs_new_node().
Meanwhile, CPU1 call sysfs_remove_dir() and sysfs_put(). This result in
glue_dir->sd is freed and it's reference count will be 0. Then CPU2 call
kernfs_get(glue_dir) will trigger a warning in kernfs_get() and increase
it's reference count to 1. Because glue_dir->sd is freed by CPU1, the next
call kernfs_add_one() by CPU2 will fail(This is also use-after-free)
and call kernfs_put() to decrease reference count. Because the reference
count is decremented to 0, it will also call kmem_cache_free() to free
the glue_dir->sd again. This will result in double free.
In order to avoid this happening, we also should make sure that kernfs_node
for glue_dir is released in CPU1 only when refcount for glue_dir kobj is
1 to fix this race.
The following calltrace is captured in kernel 4.14 with the following patch
applied:
commit 726e41097920 ("drivers: core: Remove glue dirs from sysfs earlier")
--------------------------------------------------------------------------
[ 3.633703] WARNING: CPU: 4 PID: 513 at .../fs/kernfs/dir.c:494
Here is WARN_ON(!atomic_read(&kn->count) in kernfs_get().
....
[ 3.633986] Call trace:
[ 3.633991] kernfs_create_dir_ns+0xa8/0xb0
[ 3.633994] sysfs_create_dir_ns+0x54/0xe8
[ 3.634001] kobject_add_internal+0x22c/0x3f0
[ 3.634005] kobject_add+0xe4/0x118
[ 3.634011] device_add+0x200/0x870
[ 3.634017] _request_firmware+0x958/0xc38
[ 3.634020] request_firmware_into_buf+0x4c/0x70
....
[ 3.634064] kernel BUG at .../mm/slub.c:294!
Here is BUG_ON(object == fp) in set_freepointer().
....
[ 3.634346] Call trace:
[ 3.634351] kmem_cache_free+0x504/0x6b8
[ 3.634355] kernfs_put+0x14c/0x1d8
[ 3.634359] kernfs_create_dir_ns+0x88/0xb0
[ 3.634362] sysfs_create_dir_ns+0x54/0xe8
[ 3.634366] kobject_add_internal+0x22c/0x3f0
[ 3.634370] kobject_add+0xe4/0x118
[ 3.634374] device_add+0x200/0x870
[ 3.634378] _request_firmware+0x958/0xc38
[ 3.634381] request_firmware_into_buf+0x4c/0x70
--------------------------------------------------------------------------
Fixes: 726e41097920 ("drivers: core: Remove glue dirs from sysfs earlier")
Signed-off-by: Muchun Song <smuchun@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Link: https://lore.kernel.org/r/20190727032122.24639-1-smuchun@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 726e41097920a73e4c7c33385dcc0debb1281e18 upstream. For devices with a class, we create a "glue" directory between the parent device and the new device with the class name. This directory is never "explicitely" removed when empty however, this is left to the implicit sysfs removal done by kobject_release() when the object loses its last reference via kobject_put(). This is problematic because as long as it's not been removed from sysfs, it is still present in the class kset and in sysfs directory structure. The presence in the class kset exposes a use after free bug fixed by the previous patch, but the presence in sysfs means that until the kobject is released, which can take a while (especially with kobject debugging), any attempt at re-creating such as binding a new device for that class/parent pair, will result in a sysfs duplicate file name error. This fixes it by instead doing an explicit kobject_del() when the glue dir is empty, by keeping track of the number of child devices of the gluedir. This is made easy by the fact that all glue dir operations are done with a global mutex, and there's already a function (cleanup_glue_dir) called in all the right places taking that mutex that can be enhanced for this. It appears that this was in fact the intent of the function, but the implementation was wrong. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Zubin Mithra <zsm@chromium.org> Cc: Guenter Roeck <groeck@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3297c8fc65af5d40501ea7cddff1b195cae57e4e ]
There is a race window in device_shutdown(), which may cause
-1. parent device shut down before child or
-2. no shutdown on a new probing device.
For 1st, taking the following scenario:
device_shutdown new plugin device
list_del_init(parent_dev);
spin_unlock(list_lock);
device_add(child)
probe child
shutdown parent_dev
--> now child is on the tail of devices_kset
For 2nd, taking the following scenario:
device_shutdown new plugin device
device_add(dev)
device_lock(dev);
...
device_unlock(dev);
probe dev
--> now, the new occurred dev has no opportunity to shutdown
To fix this race issue, just prevent the new probing request. With this
logic, device_shutdown() is more similar to dpm_prepare().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 84d0c27d6233a9ba0578b20f5a09701eb66cee42 upstream. syzbot is hitting WARN() at kernfs_add_one() [1]. This is because kernfs_create_link() is confused by previous device_add() call which continued without setting dev->kobj.parent field when get_device_parent() failed by memory allocation fault injection. Fix this by propagating the error from class_dir_create_and_add() to the calllers of get_device_parent(). [1] https://syzkaller.appspot.com/bug?id=fae0fb607989ea744526d1c082a5b8de6529116f Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+df47f81c226b31d89fb1@syzkaller.appspotmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f77af15165847406b15d8f70c382c4cb15846b2a upstream.
The TPM class has some common shutdown code that must be executed for
all drivers. This adds some needed functionality for that.
Signed-off-by: Josh Zimmerman <joshz@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 74d6b3ceaa17 ("tpm: fix suspend/resume paths for TPM 2.0")
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH: "Here are the "big" driver core patches for 4.9-rc1. Also in here are a number of debugfs fixes that cropped up due to the changes that happened in 4.8 for that filesystem. Overall, nothing major, just a few fixes and cleanups. All of these have been in linux-next with no reported issues" * tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits) drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent() drivers: dma-coherent: Fix DMA coherent size for less than page MAINTAINERS: extend firmware_class maintainer list debugfs: propagate release() call result driver-core: platform: Catch errors from calls to irq_get_irq_data sysfs print name of undiscoverable attribute group carl9170: fix debugfs crashes b43legacy: fix debugfs crash b43: fix debugfs crash debugfs: introduce a public file_operations accessor device core: Remove deprecated create_singlethread_workqueue drivers/base dmam_declare_coherent_memory leaks platform: don't return 0 from platform_get_irq[_byname]() on error cpu: clean up register_cpu func dma-mapping: use vma_pages(). drivers: dma-coherent: use vma_pages(). attribute_container: Fix typo base: soc: make it explicitly non-modular drivers: base: dma-mapping: page align the size when unmap_kernel_range platform driver: fix use-after-free in platform_device_del() ...
The global mutex of 'gdp_mutex' is used to serialize creating/querying glue dir and its cleanup. Turns out it isn't a perfect way because part(kobj_kset_leave()) of the actual cleanup action() is done inside the release handler of the glue dir kobject. That means gdp_mutex has to be held before releasing the last reference count of the glue dir kobject. This patch moves glue dir's cleanup after kobject_del() in device_del() for avoiding the race. Cc: Yijing Wang <wangyijing@huawei.com> Reported-by: Chandra Sekhar Lingutla <clingutla@codeaurora.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If device_add_property_set() is called for a device, a secondary fwnode is allocated and assigned to the device but currently not freed once the device is removed. This can be triggered on Apple Macs if a Thunderbolt device is plugged in on boot since Apple's NHI EFI driver sets a number of properties for that device which are leaked on unplug. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If multiple devices share single firmware node like it is case with MFD devices, the same firmware node (ACPI) is assigned to all of them. The function also modifies the shared firmware node in order to preserve secondary firmware node of the device in question. If the new device which is sharing the firmware node does not have secondary node it will be NULL which will be assigned to the secondary node of the shared firmware node losing all built-in properties. Prevent this by setting the secondary firmware node only if the replacement is non-NULL. Print also warning if someone tries to overwrite secondary node that has already been assigned. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>