| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: cs35l34: drain threaded IRQ before runtime suspend
cs35l34_runtime_suspend() currently switches the codec into
regcache_cache_only(true), asserts reset low, and powers the device off
without first quiescing the threaded IRQ registered by
devm_request_threaded_irq(). That leaves a window where
cs35l34_irq_thread() can still run after suspend has removed live
hardware access.
A running system can reach this during runtime PM while the driver still
has critical fault IRQs unmasked. If the threaded handler runs in that
window, it reads volatile INT_STATUS_1..4 after cache_only has been
enabled, ignores the regmap_read() failures, and can still execute the
PROT_RELEASE_CTL release sequence or the BST fault power-down writes.
Use disable_irq() before entering cache_only/reset-low/power-off so any
in-flight threaded handler is drained and no new IRQ thread can run
while the device is suspended. Re-enable the IRQ only after
runtime_resume() has restored live register access with regcache_sync().
Since probe only logs request_threaded_irq() failures and keeps going,
track whether the IRQ was actually installed before disabling or
re-enabling it. |
| In the Linux kernel, the following vulnerability has been resolved:
nvme: add missing SRCU grace period in error path
nvme_alloc_ns() error path at out_unlink_ns removes ns from the
namespace head siblings list with list_del_rcu(&ns->siblings) but
does not wait for SRCU readers before freeing the namespace struct.
Multipath code iterates the head->list under srcu_read_lock() in
nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent
reader can still hold a reference to ns when kfree(ns) runs.
The normal removal path in nvme_ns_remove() correctly calls
synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for
in-progress readers. Add the same grace period in the error path. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: fsl-edma: tracing: no ptr dereference during log output
The fsl edma events store a pointer to a struct fsl_edma_engine in the
ringbuffer and dereference it when a log entry is printed. At this time,
the pointer may no longer be valid.
Event injection can be used to trigger a crash:
$ cd /sys/kernel/tracing
$ echo 'value = 0' > events/fsl_edma/edma_writeb/inject
$ cat trace
The log output needs only edma->membase. Add a membase field at the end
of the event and use the new field for log output. Keep the existing
fields for backward compatibility. |
| In the Linux kernel, the following vulnerability has been resolved:
dm: fix resume-vs-remove race
If the user issues the resume ioctl and the remove ioctl at the same
time, it may be possible that the device is resumed after it is suspended
in __dm_destroy. The result is that the table is destroyed without
calling the postsuspend method.
Dm targets expect that they may be removed only after the postsuspend
method method was called. If we break this expectation, it can cause
misbehavior in various targets. For example - in the dm-integrity target,
the reboot notifier is not unregistered, leading to use-after-free.
Fix this bug by refusing to resume if the device is being destroyed. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Consume the locked rmap value in the lockless rmap walk
__kvm_rmap_lock() deliberately elides the rmap lock when it observes an
empty rmap. In that case kvm_rmap_lock_readonly() also re-enables
preemption and returns zero, so the caller holds neither the rmap lock
nor a preemption reference. The elision documents the invariant it
relies on:
* Elide the lock if the rmap is empty, as lockless walkers (read-only
* mode) don't need to (and can't) walk an empty rmap, nor can they add
* entries to the rmap. I.e. the only paths that process empty rmaps
* do so while holding mmu_lock for write, and are mutually exclusive.
kvm_rmap_age_gfn_range() ignores the returned value and unconditionally
enters for_each_rmap_spte_lockless(). The iterator started with
rmap_get_first(), which re-reads rmap_head->val rather than using the
value returned by the lock. If a writer populates the rmap between the
lock's read and the iterator's re-read, the aging path walks the newly
installed rmap without holding its lock.
For a KVM_RMAP_MANY rmap this leaves the walker following a
pte_list_desc chain that it never locked. A writer holding mmu_lock for
write may free that chain (e.g. kvm_zap_all_rmap_sptes() on the recycle
path, or any rmap zap) via kmem_cache_free() while the walk is in
progress, giving a slab use-after-free. Nothing serialises the two: the
aging path runs without mmu_lock when CONFIG_KVM_MMU_LOCKLESS_AGING=y,
and the rmap lock that would otherwise exclude the writer was elided.
Because the empty path re-enables preemption, the interval between the
two reads can span an arbitrary scheduling delay.
Fix the class of bug by having the lockless walk consume the value
returned by the lock instead of re-reading the rmap. Split
rmap_get_first() into __rmap_get_first(), which starts an iterator from
an already-read rmap value, and make for_each_rmap_spte_lockless() take
that value and call __rmap_get_first() directly.
kvm_rmap_age_gfn_range() passes the value returned by
kvm_rmap_lock_readonly(): when the lock was elided the value is zero,
__rmap_get_first() returns NULL, and the walk is skipped. No lockless
walker re-reads the rmap, so the lock-elision invariant cannot be
violated, and no lock()-without-paired-unlock() path is added to the
aging code. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF
The atlas driver requests its hardware data-ready IRQ with
devm_request_threaded_irq(); its threaded handler queues an irq_work,
atlas_work_handler(), that calls iio_trigger_poll(data->trig).
The IRQ is devm-managed, so free_irq() runs from the devres unwind after
atlas_remove() returns without flushing that irq_work. Once a buffer is
enabled, conversion-complete IRQs keep firing and queueing it; a pending
irq_work can therefore run after the unwind has freed atlas_data/indio_dev
and the trigger, when atlas_work_handler() derives the atlas_data pointer
via container_of() and dereferences data->trig, a use-after-free.
Call iio_trigger_poll_nested() directly from the threaded handler instead
of bouncing through irq_work. free_irq() then drains the threaded handler,
closing the window; other iio drivers with a threaded data-ready IRQ do the
same (e.g. bmi270).
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: buffer: Fix potential use-after-free in anonymous buffer release
An anonymous buffer handle holds a reference to the underlying IIO device.
The reference is dropped in the buffer handle's release function. If the
device has been removed, either through unbind or hot-unplug, the buffer
handle might hold the last reference.
The release function takes the mutex for the buffer using a guard, which
means the unlock happens after all the code in the function, including
`iio_device_put()`. If the anonymous buffer holds the last reference this
might free both the IIO device and the buffer, which contains the mutex,
leading to use-after-free when the mutex is unlocked.
Fix this by using a scoped guard just around the buffer dmabuf list access,
making sure the mutex is unlocked before releasing the IIO device.
Version 10 of the patch that introduced this issue used this exact scheme
of first unlocking and then dropping the reference [1]. During review it
was suggested to use a guard instead, and version 11 made that change [2]. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: fix stale receive device on merged fragments
Fragment reassembly reuses the skb from the highest-numbered buffered
fragment as the merged packet. When that fragment was received on a hard
interface which is deleted before the chain completes, the merged skb can
re-enter the receive path with a stale skb->dev and skb_iif.
batadv_batman_skb_recv() passes such merged packets through the normal
receive handlers again. DAT and bridge loop avoidance both derive the ARP
header length from skb->dev, so they can dereference the freed net_device
before the packet reaches the local mesh interface.
Refresh the receive device metadata from the current receive device before
running the packet handlers. This keeps internally reinjected merged
fragments consistent with the normal receive path after hard interface
teardown. |
| In the Linux kernel, the following vulnerability has been resolved:
ftrace: Take trace_array reference before accessing its ftrace_ops
The trace instance files set_ftrace_filter and set_ftrace_notrace was
updated to work with specific trace instances (trace_arrays). The issue is
that when these files are opened, there is a small race window where it
will use the ftrace_ops from the inode->private pointer to get a reference
to the trace_array and then take its reference. The problem is that the
ftrace_ops itself could be freed. If the rmdir on the instance happens at
the same time the set_ftrace_filter file is opened, the rmdir could have
also freed the ftrace_ops and referencing it will cause a use-after-free
bug and crash the kernel.
Instead, pass in the trace_array as the file private data (NULL for the
top level instance), and then pass both the trace_array and the ftrace_ops
to the ftrace_regex_open() function. If the trace_array is NULL, then it
just uses the ftrace_ops without the need to take its reference (like
normal). If the ftrace_ops is NULL, that is only the case for the top
level instance and the global_ops can be used.
This allows the trace_array to have its reference incremented before
touching the ftrace_ops that could also be freed when the instance is. |
| In the Linux kernel, the following vulnerability has been resolved:
futex: Prevent rcuwait use-after-free during requeue PI
On PREEMPT_RT, FUTEX_CMP_REQUEUE_PI can trigger a KASAN report
(slab-out-of-bounds) in futex_requeue_pi_complete() invocation of
rcuwait_wake_up().
The futex_q used by futex_wait_requeue_pi() is allocated on the waiter's
stack. An early wakeup can race with a PI requeue as follows:
waiter requeue task
------ ------------
futex_wait_requeue_pi()
futex_do_wait()
schedule()
futex_requeue
futex_proxy_trylock_atomic()
futex_requeue_pi_prepare()
Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IN_PROGRESS
* timeout/ signal wakes waiter *
futex_requeue_pi_wakeup_sync()
Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT
requeue_pi_wake_futex
futex_requeue_pi_complete()
cmpxchg Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_LOCKED
rcuwait_wait_event()
if (atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT)
break /* no schedule() */
/* q.pi_state->owner == current */
futex_private_hash_put()
/* return from syscall */
rcuwait_wake_up(&q->requeue_wait)
/* q is gone */
futex_requeue_pi_complete() publishes Q_REQUEUE_PI_LOCKED before
calling rcuwait_wake_up(). The waiter observes this state in
rcuwait_wait_event() before invoking schedule() in rcuwait_wait_event().
Here, the waiter is free leave the syscall before requeue task can
complete the wake.
To address this race skip rcuwait_wake_up() in the Q_REQUEUE_PI_LOCKED
case.
This state is only published by requeue_pi_wake_futex(), which saves
q->task before futex_requeue_pi_complete() and wakes the waiter via
wake_up_state().
This wake is intended to wake the waiter from its futex_do_wait() sleep.
If the waiter is still sleeping there, it can not get into the
Q_REQUEUE_PI_WAIT state (and require this removed wake).
Should the waiter be woken up from futex_do_wait() by other means (as in
this example) and sleep in futex_requeue_pi_wakeup_sync() then the
wake_up_state() from requeue_pi_wake_futex() will wake it, too.
Should the waiter task terminate before wake_up_state() had a chance to
wake the task then the task pointer does not become invalid because the
futex_hash_bucket::lock is held and the task pointer is RCU protected.
[bigeasy: Updated comment and commit message] |
| In the Linux kernel, the following vulnerability has been resolved:
s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects
In order to traverse or add/remove ap_matrix_mdev objects in the
matrix_dev->mdev_list, the matrix_dev->guests_lock mutex must be held.
There are two functions that access the list without holding the mutex:
vfio_ap_mdev_probe function
~~~~~~~~~~~~~~~~~~~~~~~~~~~
The vfio_ap_mdev_probe function uses the matrix_dev->mdevs_lock
mutex to guard the add of a newly created ap_matrix_mdev object to the
matrix_dev->mdev_list. This mutex does not protect list access; its purpose
is to guard against concurrent access to fields contained in an
ap_matrix_mdev object. This could lead to kernel memory corruption or
use-after-free if another mdev is created or removed concurrently.
The adding of an ap_matrix_mdev object to matrix_dev->mdev_list
is now guarded by the matrix_dev->guests_lock which is the correct
way to protect against concurrent mdev_list access.
Also removed the following two lines of code because the matrix_mdev is
allocated via vfio_alloc_device macro which uses kzalloc, so req_trigger
and cfg_chg_trigger are already zero-initialised when the struct is
allocated before the call to vfio_register_emulated_iommu_dev. This
prevents a window whereby these triggers are set to NULL after
the device is exposed to userspace.
matrix_mdev->req_trigger = NULL;
matrix_mdev->cfg_chg_trigger = NULL;
vfio_ap_mdev_for_queue function
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The status_show function that supports display of the status attribute of
the devices in /sys/bus/ap/devices calls the vfio_ap_mdev_for_queue
function which iterates the matrix_dev->mdev_list to find the object
representing the queue device whose status is to be displayed. In order to
traverse this list, the matrix_dev->guests_lock mutex must be held.
To fix this, the guests_lock mutex is taken prior to taking the
matrix_dev->mdevs_lock mutex in the status_show function. It is taken
there rather than the vfio_ap_mdev_for_queue function - where it is
needed - because it must be taken prior to the mdevs_lock mutex in order to
adhere to the proper locking order and prevent a lockdep splat; also
because the mdevs_lock is needed there to access fields within
the matrix_mdev object in that function.
See the vfio-ap-locking.rst in the linux kernel tree. |
| In the Linux kernel, the following vulnerability has been resolved:
nvme-fc: fix double free of fabrics options when nvme_add_ctrl() fails
nvmf_create_ctrl() owns the fabrics options and frees them whenever
->create_ctrl() returns an error, so a transport must not free them on
its own error paths. nvme-fc tracks this by testing ctrl->ctrl.opts in
nvme_fc_ctrl_free(), which requires nvme_fc_init_ctrl() to clear that
pointer on every error exit.
The coupling is implicit, and commit 1a9e218195a5 ("nvme: split device
add from initialization") broke it by adding a second error exit. When
nvme_add_ctrl() fails, nvme_fc_init_ctrl() jumps to out_put_ctrl:, past
the "ctrl->ctrl.opts = NULL" that only sits on the fail_ctrl: path, so
nvme_fc_ctrl_free() frees the options and nvmf_create_ctrl() frees them
a second time:
BUG: KASAN: slab-use-after-free in nvmf_free_options+0x30/0x190
nvmf_free_options+0x30/0x190 drivers/nvme/host/fabrics.c:1284
nvmf_create_ctrl drivers/nvme/host/fabrics.c:1374 [inline]
Freed by task 5534:
nvme_fc_ctrl_free drivers/nvme/host/fc.c:2374 [inline]
nvme_fc_init_ctrl+0xe17/0x1450 drivers/nvme/host/fc.c:3605
nvme_add_ctrl() fails when dev_set_name() cannot allocate, so this is
reachable under memory pressure or fault injection. Without KASAN the
options are freed twice.
Rather than clear the pointer on the second exit as well, derive
ownership the way nvme-tcp, nvme-rdma and nvme-loop do, from list
membership: their free_ctrl leaves the options alone unless the
controller made it onto the transport list.
The list cannot simply be populated on the success path as it is there.
nvme-fc runs the initial connect synchronously via flush_delayed_work(),
and the controller has to be reachable on rport->ctrl_list for the whole
of it: nvme_fc_unregister_remoteport() needs to find it to signal
connectivity loss, nvme_fc_match_disconn_ls() matches an incoming
Disconnect Association LS against ctrl->association_id, which is only
assigned during that window, nvme_fc_resume_controller() needs it on
remoteport re-registration, and nvme_fc_existing_controller() uses it to
reject a duplicate connect racing the one in flight.
Keep the insertion where it is and add a fail_unlist: label, falling
into fail_ctrl:, for the error paths that run after it. The earlier
error paths never reach the insertion and keep using fail_ctrl:
directly, so the list is only touched where the controller is actually
on it.
nvme_fc_ctrl_free() cannot use the plain "goto free_ctrl" the other
transports use, because it still has to put_device(), release the rport
reference and free the ida entry for resources taken before the
insertion. Sample list_empty() under rport->lock instead.
ctrl->ctrl.opts also stays valid for the whole teardown now. That is
not the bug being fixed, but it removes some fragility around the old
idiom: nvme_free_ctrl() calls nvme_auth_free() before ->free_ctrl(), and
ctrl_max_dhchaps() dereferences ctrl->opts without a NULL check when
ctrl->dhchap_ctxs is set, which nvme-fc permits since NVMF_ALLOWED_OPTS
allows the dhchap options. The nvme sysfs attributes that dereference
ctrl->opts, such as hostnqn and address, evaluate their is_visible()
test once at device_add() time and stay readable until
cdev_device_del(). |
| In the Linux kernel, the following vulnerability has been resolved:
dm: fix race when loading and unloading a table
If the userspace calls two concurrent table load ioctls and one of them
succeeds and the other fails, there is a race condition because
dm_setup_md_queue walks &md->table_devices without any lock. If the walk
races with dm_table_destroy -> free_devices -> dm_put_table_device, there
is access to invalid memory.
Fix this race by extending the lock over the list walk. |
| In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()
skb_zerocopy() copies frags from @from into @to. On an
skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive
operation on the source skb the copy helper does not own. That completes
@from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the
SKBFL_SHARED_FRAG page-ownership marker.
Both callers already report the failure on their own drop path.
nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in
the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by
dropping it here.
On Open vSwitch's OVS_ACTION_ATTR_USERSPACE path the skb is not freed on
this error: do_execute_actions() ignores output_userspace()'s return
value and, unless the upcall was the last action, keeps forwarding the
same skb through the flow's remaining actions. The uarg is completed
while that skb is still in flight, telling the producer its buffers are
free, and SKBFL_SHARED_FRAG is cleared on an skb the rest of the stack
still handles. That flag is what makes esp_input() call skb_cow_data()
instead of decrypting in place, so a later local ESP delivery can
decrypt over frags the skb does not own privately.
Leave error reporting to the callers. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_midi2: fix use-after-free in string attribute show path
f_midi2_opts_str_show() takes the string lock internally, but its
callers dereference the opts->info.<field> pointer before calling it,
outside the lock. This races with f_midi2_opts_str_store(), which
frees the old string under opts->lock when the attribute is written
concurrently, the show path can read a pointer that gets freed
before the lock inside str_show() is even taken.
Change f_midi2_opts_str_show() to take a pointer to the string field,
matching the existing pattern in f_midi2_opts_str_store(), and
dereference it only after the lock is held. Update all three callers
(iface_name, block name, and the EP string option macro) accordingly. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: qcom-pmic: cancel reset_work on stop
pdphy_stop() disables IRQs but leaves reset_work pending. If the IRQ
handler schedules it just before disable_irq(), the work runs after
remove() frees the struct via devm.
Call cancel_work_sync() after disabling IRQs to close the window.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
media: usbtv: keep device alive while ALSA card exists
The ALSA PCM callbacks store the driver state in pcm->private_data. An
open PCM file can outlive USB disconnect because usbtv_audio_free() uses
snd_card_free_when_closed(). The disconnect path can then drop the V4L2
device reference and free struct usbtv before ALSA releases the substream,
so a later close dereferences freed memory in snd_usbtv_pcm_close().
Take a V4L2 device reference for the ALSA card and drop it from the card
private_free callback. This keeps struct usbtv valid until ALSA has closed
the remaining files and freed the card. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: bpf: serialize device reference release in struct_ops destroy path
__hid_bpf_ops_destroy_device() and hid_bpf_unreg() can race on the
same registration reference, double-putting struct hid_device and
freeing it while hid_destroy_device() still uses it. Serialize the
remove/NULL decision under hdev->bpf.prog_list_lock so exactly one
path releases each registration reference: unreg re-checks ops->hdev
under the lock and returns without putting when the destroy path
already cleared it; all put_device() calls happen after the lock is
dropped, which is safe because a concurrent unreg then observes
ops->hdev == NULL under the lock.
Background: each successful attach (hid_bpf_ops_reg) acquires one
device reference (hid_get_device()). Two paths can release it:
- device destruction: hid_destroy_device() -> hid_bpf_destroy_device()
-> __hid_bpf_ops_destroy_device(), which walks hdev->bpf.prog_list
under rcu_read_lock() and drops one reference per attached program;
- BPF link release: bpf map delete (no BPF_F_LINK) synchronously calls
st_ops->unreg() -> hid_bpf_unreg(), which drops the reference for
its own registration.
The coordination handshake (e->hdev = NULL on the destroy side vs
"if (!hdev) return" on the unreg side) is a TOCTOU check: the two
paths run under different lock domains (rcu_read_lock vs
prog_list_lock), so a concurrent unreg can read ops->hdev as
non-NULL, block on prog_list_lock, and then proceed while the
destroy traversal executes - both paths then drop the same
reference. The refcount reaches zero legitimately (each decrement
is individually valid), so no refcount_t saturation fires: the
device is simply freed while the transport is still inside
hid_destroy_device(), and subsequent teardown touches freed memory.
The fix serializes the remove/NULL decision under prog_list_lock on
both sides and moves the destroy-side puts outside the lock. With
the lock held, plain reads/writes of ops->hdev are sufficient; no
READ_ONCE/WRITE_ONCE are added, keeping the patch minimal.
Unlocked-read safety: the unlocked read of ops->hdev at the top of
hid_bpf_unreg() cannot touch a freed device, because the unreg path
itself still holds this registration's reference (released only by
its own hid_put_device() after the lock is dropped), and a destroy
traversal that already cleared ops->hdev makes the lock-internal
re-check return early without any put. At most one of the two
paths releases each registration reference. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Have show_event_filters/triggers files take trace array ref
The newly added files show_event_filters and show_event_triggers that show
all filters or triggers that are set within the trace array do not take a
reference for the trace array it is showing. Without taking a reference,
the trace_array may be freed via "rmdir" while a task is reading one of
theses files. Those files iterate all the events within an instance
(trace_array) and nothing prevents that instance from being freed while
its data is being read. This causes a use-after-free crash.
Have the open of both those files take the trace_array reference via the
trace_array_get() that prevents the trace_array from being freed while the
files are opened. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/vfio-ap: fix stale pqap_hook pointer on error in vfio_ap_mdev_set_kvm()
In vfio_ap_mdev_set_kvm(), kvm->arch.crypto.pqap_hook is set to
&matrix_mdev->pqap_hook before the update locks are acquired and the
mdev list is checked for a conflicting assignment. If another mdev is
already attached to the same KVM instance, the function returns -EPERM
without restoring the hook pointer, leaving kvm->arch.crypto.pqap_hook
pointing at the failing matrix_mdev instead of the mdev that legitimately
owns the KVM.
Since matrix_mdev->kvm is never set on this error path,
vfio_ap_mdev_unset_kvm() will not clean up the hook when matrix_mdev
is later closed. If matrix_mdev is subsequently freed, any PQAP
instruction executed by the guest will dereference the stale pointer
through pqap_hook_rwsem, resulting in a use-after-free.
Since kvm->arch.crypto.pqap_hook is only set in the vfio_ap_mdev_set_kvm()
function and is cleared in the vfio_ap_mdev_unset_kvm() function, a check
for 'kvm->arch.crypto.pqap_hook != NULL' is all that is needed to determine
whether it belongs to another mdev. This will alleviate the need to iterate
the matrix_dev->mdev_list list to see if the kvm object is assigned to
another mdev.This was introduced in v3 to alleviate the need to take the
mdevs_lock while iterating the list; however, this did not prevent a
potential race condition.
The pqap_hook_rwsem(write) is now performed inside
get_update_locks_for_kvm(), which is updated to acquire
pqap_hook_rwsem(write) between kvm->lock and mdevs_lock. This ordering
is consistent with the PQAP intercept path, which acquires pqap_hook_rwsem
in read mode while srcu is held under vcpu->mutex, establishing the
dependency: kvm->lock -> vcpu->mutex -> srcu -> pqap_hook_rwsem(read).
The pqap_hook_rwsem is now released inside the
release_update_locks_for_kvm(), which is updated to release
pqap_hook_rwsem(write) between mdevs_lock and kvm->lock.
Additionally, kvm_put_kvm() in vfio_ap_mdev_unset_kvm() is moved
after release_update_locks_for_kvm(). Previously it was called while
kvm->lock was held; if it were ever the last reference, kvm_destroy_vm()
would run under kvm->lock, which would deadlock. |
