| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
netlink: do not free nlk->groups while lockless readers can use it
netlink_realloc_groups() uses krealloc() under netlink_table_grab().
Whenever NLGRPSZ(groups) lands in a different kmalloc bucket, the old
bitmap is freed immediately.
Two readers of nlk->groups / nlk->ngroups do not hold the netlink
table lock:
1) sk_diag_dump_groups(). Hashed (bound) sockets are dumped from the
rhashtable walk in __netlink_diag_dump(), which only holds RCU.
Only the mc_list part of the dump takes nl_table_lock.
2) netlink_native_seq_show() (/proc/net/netlink), whose walk has been
lockless since commit 21e4902aea80 ("netlink: Lockless lookup with
RCU grace period in socket release").
Both can read a freed buffer, and sk_diag_dump_groups() can also read
past the end of the old (smaller) buffer if it happens to load the old
@groups pointer together with the new @ngroups value, copying the
result into a NETLINK_DIAG_GROUPS attribute.
This is the same class of bug that commit f773608026ee ("netlink:
access nlk groups safely in netlink bind and getname") fixed for bind()
and getname(); these two readers were missed. Simply grabbing the table
lock in sk_diag_dump_groups() is not an option, because it is also
called with nl_table_lock already held from the mc_list section of the
dump.
Make the lockless readers safe instead:
- Allocate a new bitmap and free the old one after an RCU grace period,
instead of relying on the implicit kfree() done by krealloc().
- Publish @groups before @ngroups, both with release semantics, and have
the lockless readers load @ngroups first. A reader can then never pair
the new (bigger) size with the old (smaller) buffer, and a reader
picking up the new pointer while still seeing the old size is
guaranteed to see the initialized bitmap.
netlink_realloc_groups() is called from process context (bind() and
setsockopt()), so kfree_rcu_mightsleep() can be used, once the table
has been released. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/i2c: Disable IRQ on unbind
Currently, struct xe_i2c is freed before SGUnit IRQ is disabled in unbind
path, leaving a potential UAF in case I2C IRQ is hit during this small
window. Explicitly disable I2C IRQ in xe_i2c_remove() and fix this.
(cherry picked from commit 8ba5c8b8ab3fd362267c11df2cd5a90ee46f6e24) |
| In the Linux kernel, the following vulnerability has been resolved:
posix-cpu-timers: Prevent freeing a timer which is queued on the expiry list
Kijo analyzed another race in the POSIX CPU timer code:
Commit bf635681c906 converted cpu_timer::firing from a tristate value to a
boolean. This lost the distinction between "not owned by the firing list"
and "still owned, but delivery was canceled". The resulting race is:
expiry handler timer_settime() timer_delete()
-------------- --------------- --------------
collect timer onto
private firing list
firing = true
observes firing = true
firing = false
return TIMER_RETRY
wait for handler
observes firing = false
finish deletion
unhash and free timer
resume list traversal
read freed elist.next
-> UAF
The firing bit is clearly the wrong indicator since that commit.
Check whether the timer is queued on the expiry list or not instead. If it
is queued clear the firing bit to prevent signal delivery as before and
return TIMER_RETRY so the caller unlocks the timer which allows the expiry
code to make progress and remove it from the list. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: don't free driver-owned scan requests
When an interface goes down while a scan is running, cfg80211 completes
the scan towards userspace and frees the scan request. However, the
driver can be convinced that it owns the request, since the cancellation
is (intended to be) asynchronous.
The WARN_ON() in the netdev notifier was meant to catch this, but it's
not actually avoidable, so it triggers and we get a UAF in scan_done().
There doesn't seem to be a great way around it, so just track that the
driver is still convinced it owns the request, and then just free it on
completion if it was already cancelled. Also remove the warnings since
they can trigger in the intended architecture. |
| In the Linux kernel, the following vulnerability has been resolved:
drop_monitor: use timer_shutdown_sync() to prevent timer rearming during teardown
In drop_monitor teardown paths (net_dm_trace_off_set(),
net_dm_hw_monitor_stop(), and error unwind paths in net_dm_trace_on_set()
and net_dm_hw_monitor_start()), per-CPU timers are stopped using
timer_delete_sync() followed by cancel_work_sync().
However, there is a circular dependency between send_timer and
dm_alert_work:
1) sched_send_work() (timer callback) schedules dm_alert_work.
2) send_dm_alert() / net_dm_hw_summary_work() calls reset_per_cpu_data()
or net_dm_hw_reset_per_cpu_data().
3) If memory allocation fails under memory pressure in the reset
function, it re-arms the timer via mod_timer(&data->send_timer, ...).
If dm_alert_work is running concurrently while timer_delete_sync()
executes on another CPU, an allocation failure in the worker will
re-arm the timer after timer_delete_sync() has already returned.
Once cancel_work_sync() completes and module_put() is called, the timer
remains active in the timer wheel. If the module is then unloaded, the
timer will fire and execute sched_send_work() in freed memory,
triggering a kernel panic / use-after-free.
Switch from timer_delete_sync() to timer_shutdown_sync(). This guarantees
that any in-flight timer handler has finished and prevents subsequent
re-arming attempts from running workers from succeeding. When monitoring
is restarted later, timer_setup() is invoked, which cleanly
re-initializes the timer. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: virtio: reset device before deleting virtqueues
virtsnd_remove() and virtsnd_freeze() delete the virtqueues before
resetting the device. del_vqs() frees the vring backing, but does not
provide a generic device quiesce operation. In particular, modern
virtio-pci keeps enabled queues active until the device is reset.
Reset the device before deleting the virtqueues so it can no longer
access the vring memory when that memory is released. This also covers
probe failures after DRIVER_OK, which unwind through virtsnd_remove(). |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: get the wiphy out of a dying network namespace
When a network namespace is destroyed, cfg80211_pernet_exit() moves any
wiphy back to the initial namespace, and just warns if that fails. But
moving an interface can fail (due to allocation failures), and then the
wiphy is left behind with a garbage netns pointer:
Kernel mode fault at addr 0x30
genlmsg_multicast_netns.constprop.0+0x46/0xcf [cfg80211]
nl80211_notify_wiphy+0xcd/0xe8 [cfg80211]
wiphy_unregister+0x169/0x3fc [cfg80211]
Note that commit debac3a20dec ("net: Remove conflicting altnames for
dying netns in __dev_change_net_namespace().") fixed another path
that could reach it without allocation failures.
Remove interfaces that cannot be moved instead of failing the switch,
so that the wiphy always ends up in the initial namespace. In this
case the netdev core will unregister the interfaces anyway. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: core: Fix potential UAF after asynchronous card release
Usually a sound driver releases the resources assigned to the card via
snd_card_free(), and it synchronizes with the whole release procedure.
However, when the card is released asynchronously via
snd_card_free_when_closed() like USB-audio driver, the situation is
slightly different; although the snd_card_disconnect() call at the
disconnection guarantees that any newer accesses will be gated, the
in-flight tasks might be still accessing to the underlying card->dev
device even after the disconnection, which would cause a
use-after-free in the end, as reported by fuzzers.
For addressing the bug above, this patch takes the refcount of
card->dev at initialization of the card object, and releases at its
destructor. This assures the availability of the card->dev in its
whole lifecycle. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()
kvmhv_emulate_tlbie_all_lpid() iterates the nested-guest IDR and drops
mmu_lock before calling kvmhv_emulate_tlbie_lpid(), but does not hold a
reference on the kvm_nested_guest pointer obtained from the IDR. A
concurrent vCPU issuing a single-LPID tlbie (is=2, ric=2) can race
through kvmhv_flush_nested() -> kvmhv_remove_nested() -> idr_remove /
--refcnt -> kvmhv_release_nested() -> kfree(gp) in that window, leaving
the iterating vCPU with a dangling pointer. The subsequent
mutex_lock(&gp->tlb_lock) and accesses to gp->shadow_pgtable,
gp->shadow_lpid and gp->l1_host all touch freed memory. The free path
is fully L1-controlled.
Fix this by incrementing gp->refcnt inside the loop before dropping
mmu_lock, mirroring what kvmhv_get_nested() does, and releasing the
reference with kvmhv_put_nested() after the per-guest work completes.
This is the same get/put discipline already used at every other
call site that drops mmu_lock while holding a nested-guest pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: wait for RCU readers before releasing dma_device
dma_issue_pending_all() walks the dma_device_list with
list_for_each_entry_rcu() under rcu_read_lock(). dma_device_release()
unlinks the device with list_del_rcu() and then calls
device->device_release() (which in many drivers, such as plx_dma.c,
directly calls kfree()).
Because there is no grace period between unlinking the device and
freeing it, concurrent RCU readers in dma_issue_pending_all() can
access the device after it has been freed.
The lockless walk originally relied on clients holding a dmaengine
reference to pin the provider module, and therefore the device, for as
long as they might traverse the list. Commit 8ad342a86359 ("dmaengine:
Add reference counting to dma_device struct") decoupled the dma_device
lifetime from the module reference, so the device can now be released
while a reader is still walking the list.
Add synchronize_rcu() before the device is freed, so RCU readers are
guaranteed to have finished. Keep it unconditional: providers that do
not implement device_release() free the device themselves once
dma_async_device_unregister() returns. This call will delay for a grace
period with dma_list_mutex held, which is safe and only teardown path is
delayed. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()
When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.
dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:
slab-use-after-free in dma_chan_put+0x3e6/0x4c0
Read of size 8 by task insmod/6319
Freed by task 6319:
kfree+0x225/0x470
dma_chan_put+0x395/0x4c0
dmaengine_put+0xf8/0x160
Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device. |
| In the Linux kernel, the following vulnerability has been resolved:
i2c: atr: fix dangling adapter pointer on add failure
i2c_atr_add_adapter() stores atr->adapter[chan_id] before
i2c_add_adapter() so that the I2C bus notifier can match child clients
during registration. On failure the channel is freed but the slot was
left pointing at freed memory, which can lead to use-after-free in
i2c_atr_del_adapter() / cleanup and also block reuse with -EEXIST.
Clear the slot on the i2c_add_adapter() error path before freeing chan. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: virt_wifi: don't transfer operstate before register
virt_wifi_newlink() calls netif_stacked_transfer_operstate() before
register_netdevice(). If the lower device is dormant, that queues the
new netdev on lweventlist while it is still uninitialized. If
registration fails after that, for example because of an invalid name
such as "bad/name", free_netdev() immediately frees the object. A
later linkwatch_fire_event() then use-after-frees the list entry.
Move the transfer to after netdev_upper_dev_link(), as macvlan and
ipvlan already do. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: use hlist_del_init_rcu for state_cache and state_cache_input
Commit 14acf9652e56 ("xfrm: defensively unhash xfrm_state lists in
__xfrm_state_delete") converted bydst/bysrc/byseq/byspi from
hlist_del_rcu() to hlist_del_init_rcu() so that a second
__xfrm_state_delete() on the same object becomes a no-op rather than a
write through LIST_POISON pprev. It missed state_cache and
state_cache_input, which kept hlist_del_rcu():
- hlist_del_rcu() leaves pprev = LIST_POISON2 (non-NULL), so
hlist_unhashed() returns false.
- hlist_del_init_rcu() leaves pprev = NULL, so hlist_unhashed()
returns true.
A second __xfrm_state_delete() therefore enters __hlist_del() on the
already-deleted state_cache/state_cache_input nodes and does
WRITE_ONCE(*pprev, next) through LIST_POISON2 — a write use-after-free
once the slab is reused. The corruption can in turn cause a subsequent
hlist_for_each_entry_rcu traversal to follow a dangling next pointer,
producing the read use-after-free reported in xfrm_input_state_lookup().
Switch state_cache and state_cache_input to hlist_del_init_rcu() to
match the other four lists, closing the write use-after-free and, with
it, the read use-after-free it spawns. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: core: Cancel SDIO IRQ work before freeing host
A host controller that uses sdio_signal_irq() schedules host->sdio_irq_work
from its interrupt handler. That work is only cancelled on the suspend
path (mmc_sdio_suspend()), not on the remove/free path, so a worker armed
just before the controller freed its IRQ can run after
mmc_host_classdev_release() has freed the host and dereference it through
container_of().
Cancel host->sdio_irq_work in mmc_free_host(), like the existing
host->detect drain added by commit 1036f69e2513 ("mmc: core: Cancel
delayed work before releasing host").
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: mxcmmc: cancel data work and watchdog on remove
mxcmci_remove() frees the host through the devm tail, but neither it nor
mmc_remove_host() drains the driver's own asynchronous state.
host->watchdog, a 10 s timer armed on the DMA path in mxcmci_setup_data(),
is deleted only by the DMA- and IRQ-complete paths, which the remove path
does not explicitly drain; it can therefore fire after the host is freed
and dereference it in mxcmci_watchdog(). host->datawork, armed from the
IRQ handler on the PIO path, is not cancelled by the remove path either.
Free the devm-registered IRQ, then cancel datawork and delete the watchdog
in mxcmci_remove(), before dma_release_channel(). Freeing the IRQ first
keeps a trailing handler from re-arming datawork between the cancel and
the host free. Both callbacks are non-self-rearming.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: mmci: Fix use-after-free in busy-timeout work
ux500_busy_complete() can queue ux500_busy_timeout_work for an R1b
command, but mmci_remove() never cancels it. The work can subsequently
dereference the devm-allocated mmci_host after it has been released.
Mask the controller interrupts and disable the delayed work during
removal. This drains any queued instance and stops an IRQ handler that
is still in progress from queueing the work again once it has been
disabled.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: hsq: Fix use-after-free in retry work
mmc_hsq_pump_requests() queues retry_work when request_atomic() returns
-EBUSY; today sdhci-sprd is the only consumer that implements
request_atomic(). The work is embedded in a devm-allocated mmc_hsq, but
is never cancelled during driver removal. Work still pending at unbind
can therefore run after the devm allocation has been released and
dereference hsq->mmc and hsq->mrq.
Use devm_work_autocancel() to cancel and drain retry_work before the devm
allocation is released. By the time devres cleanup begins,
mmc_remove_host() has already stopped the host, so no new requests can
arm the work.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Close the pre-enable ops error claim window
scx_alloc_and_add_sched() publishes ops->priv before
scx_root_enable_workfn() switches the state to SCX_ENABLING. An error
claimed via scx_bpf_error_bstr() from an associated BPF program in that
window is consumed by scx_disable_workfn(), which takes the pre-enable
shortcut in scx_root_disable(). The shortcut returns without any teardown
and restores SCX_DISABLED with an unconditional scx_set_enable_state() xchg
racing the enable workfn's own transition. The enable then completes with
the claim consumed: the scheduler stays up but can never be disabled again,
and bpf_scx_unreg() frees it while still in use, resulting in a
use-after-free. Both WARN_ON_ONCE()s fire back to back:
WARNING: kernel/sched/ext/ext.c:7522 at
scx_root_enable_workfn+0xeec/0x1be0, CPU#3: scx_enable_help/276
WARNING: kernel/sched/ext/ext.c:6398 at scx_root_disable+0xb50/0xdb8,
CPU#0: sched_ext_helpe/664
scx_root_enable_workfn() switches to SCX_ENABLING before the scheduler
allocation, so ops->priv is never visible while SCX_DISABLED. The allocation
failure path restores SCX_DISABLED. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/ucma: Serialize join and leave on copy_to_user failure
rdma_join_multicast() queues RoCE work that later reads the ucma_multicast
through event->param.ud.private_data, then list_add()s the CMA multicast
at the head of id_priv->mc_list. rdma_leave_multicast() matches only by
sockaddr and destroys the first hit.
ucma_process_join() used to drop ctx->mutex after a successful join and
retake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls
with the same address can therefore insert a second CMA entry before the
first thread's leave. leave then cancels the newer work and the older
worker still dereferences the ucma_multicast that the first thread frees.
Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and,
on -EFAULT, through rdma_leave_multicast() so leave cannot miss this join.
Do not leave if join itself failed: that path never published this address
on mc_list, and a leave-by-addr would destroy an earlier successful join. |
