| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits
Move the handling of fastpath userspace exits into vendor code to ensure
KVM runs vendor specific operations that need to run before userspace gains
control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM
needs to flush the PML buffer prior to exiting to userspace, otherwise any
memory written by the final KVM_RUN might never be flagged as dirty.
Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in
general, as that risks consuming stale state in a fastpath handler. That
will be addressed in a future change. |
| In the Linux kernel, the following vulnerability has been resolved:
rbd: eliminate a race in lock_dwork draining on unmap
Given how rbd_lock_add_request() and rbd_img_exclusive_lock() are
written, lock_dwork may be (re)queued more than it's actually needed:
for example in case a new I/O request comes in while we are in the
middle of rbd_acquire_lock() on behalf of another I/O request. This is
expected and with rbd_release_lock() preemptively canceling lock_dwork
is benign under normal operation.
A more problematic example is maybe_kick_acquire():
if (have_requests || delayed_work_pending(&rbd_dev->lock_dwork)) {
dout("%s rbd_dev %p kicking lock_dwork\n", __func__, rbd_dev);
mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
}
It's not unrealistic for lock_dwork to get canceled right after
delayed_work_pending() returns true and for mod_delayed_work() to
requeue it right there anyway. This is a classic TOCTOU race.
When it comes to unmapping the image, there is an implicit assumption
of no self-initiated exclusive lock activity past the point of return
from rbd_dev_image_unlock() which unlocks the lock if it happens to be
held. This unlock is assumed to be final and lock_dwork (as well as
all other exclusive lock tasks, really) isn't expected to get queued
again. However, lock_dwork is canceled only in cancel_tasks_sync()
(i.e. later in the unmap sequence) and on top of that the cancellation
can get in effect nullified by maybe_kick_acquire(). This may result
in rbd_acquire_lock() executing after rbd_dev_device_release() and
rbd_dev_image_release() run and free and/or reset a bunch of things.
One of the possible failure modes then is a violated
rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
in rbd_dev_header_info() which is called via rbd_dev_refresh() from
rbd_post_acquire_action().
Redo exclusive lock task draining to provide saner semantics and try
to meet the assumptions around rbd_dev_image_unlock(). |
| In the Linux kernel, the following vulnerability has been resolved:
parport: Fix race between port and client registration
The parport subsystem registers port devices before they are fully
initialised, resulting in a race condition where client drivers such
as lp can attach to ports that are not completely initialised or even
being torn down.
When the port and client drivers are built as modules and loaded
around the same time during boot, this occasionally results in a
crash. I was able to make this happen reliably in a VM with a
PC-style parallel port by patching parport_pc to fail probing:
> --- a/drivers/parport/parport_pc.c
> +++ b/drivers/parport/parport_pc.c
> @@ -2069,7 +2069,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base,
> if (!p)
> goto out3;
>
> - base_res = request_region(base, 3, p->name);
> + base_res = NULL;
> if (!base_res)
> goto out4;
>
and then running:
while true; do
modprobe lp & modprobe parport_pc
wait
rmmod lp parport_pc
done
for a few seconds.
In the long term I think port registration should be changed to put
the call to device_add() inside parport_announce_port(), but since the
latter currently cannot fail this will require changing all port
drivers.
For now, add a flag to indicate whether a port has been "announced"
and only try to attach client drivers to ports when the flag is set. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: close TOCTOU race while computing rcv_wnd
The MPTCP output path access locklessly the MPTCP-level ack_seq
in multiple times, using possibly different values for the data_ack
in the DSS option and to compute the announced rcv wnd for the same
packet.
Refactor the cote to avoid inconsistencies which may confuse the
peer. Also ensure that the MPTCP level rcv wnd is updated only when
the egress packet actually contains a DSS ack. |
| When an audio channel's buffer needs to be resized, the sound(4) driver checks that the buffer is not memory-mapped and then drops the channel lock to allocate a new buffer. An mmap(2) call on another thread can complete during this window, after which the resize path frees the now-mapped buffer without rechecking.
An unprivileged local user with access to a sound device can exploit this race to trigger a use-after-free in the kernel, potentially escalating privileges. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/gem: Try to fix change_handle ioctl, attempt 4
[airlied: just added some comments on how to reenable]
On-list because the cat is out of the bag and we're clearly not good
enough to figure this out in private. The story thus far:
5e28b7b94408 ("drm: Set old handle to NULL before prime swap in
change_handle") tried to fix a race condition between the gem_close and
gem_change_handle ioctls, but got a few things wrong:
- There's a confusion with the local variable handle, which is actually
the new handle, and so the two-stage trick was actually applied to the
wrong idr slot. 7164d78559b0 ("drm/gem: fix race between
change_handle and handle_delete") tried to fix that by adding yet
another code block, but forgot to add the error handling. Which meant
we now have two paths, both kinda wrong.
- dc366607c41c ("drm: Replace old pointer to new idr") tried to apply
another fix, but inconsistently, again because of the handle confusion
- this would be the right fix (kinda, somewhat, it's a mess) if we'd
do the two-stage approach for the new handle. Except that wasn't the
intent of the original fix.
We also didn't have an igt merged for the original ioctl, which is a big
no-go. This was attempted to address off-list in the original bugfix,
and amd QA people claimed the bug was fixed now. Very clearly that's not
the case. Here's my attempt to sort this out:
- Rename the local variable to new_handle, the old aliasing with
args->handle is just too dangerously confusing.
- Merge the gem obj lookup with the two-stage idr_replace so that we
avoid getting ourselves confused there.
- This means we don't have a surplus temporary reference anymore, only
an inherited from the idr. A concurrent gem_close on the new_handle
could steal that. Fix that with the same two-stage approach
create_tail uses. This is a bit overkill as documented in the comment,
but I also don't trust my ability to understand this all correctly, so
go with the established pattern we have from other ioctls instead for
maximum paranoia.
- Adjust error paths. I've tried to make the error and success paths
common, because they are identical except for which handle is removed
and on which we call idr_replace to (re)install the object again. But
that made things messier to read, so I've left it at the more verbose
version, which unfortunately hides the symmetry in the entire code
flow a bit.
- While at it, also replace the 7 space indent with 1 tab.
And finally, because I flat out don't trust my abilities here at all
anymore:
- Disable the ioctl until we have the igt situation and everything else
sorted out on-list and with full consensus.
v2:
Sashiko noticed that I didn't handle the error path for idr_replace
correctly, it must be checked with IS_ERR_OR_NULL like in
gem_handle_delete. So yeah, definitely should just the existing paths
1:1 because this is endless amounts of tricky.
Also add the Fixes: line for the original ioctl, I forgot that too. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "wireguard: device: enable threaded NAPI"
This reverts commit 933466fc50a8e4eb167acbd0d8ec96a078462e9c which is
commit db9ae3b6b43c79b1ba87eea849fd65efa05b4b2e upstream.
We have had three independent production user reports in combination
with Cilium utilizing WireGuard as encryption underneath that k8s Pod
E/W traffic to certain peer nodes fully stalled. The situation appears
as follows:
- Occurs very rarely but at random times under heavy networking load.
- Once the issue triggers the decryption side stops working completely
for that WireGuard peer, other peers keep working fine. The stall
happens also for newly initiated connections towards that particular
WireGuard peer.
- Only the decryption side is affected, never the encryption side.
- Once it triggers, it never recovers and remains in this state,
the CPU/mem on that node looks normal, no leak, busy loop or crash.
- bpftrace on the affected system shows that wg_prev_queue_enqueue
fails, thus the MAX_QUEUED_PACKETS (1024 skbs!) for the peer's
rx_queue is reached.
- Also, bpftrace shows that wg_packet_rx_poll for that peer is never
called again after reaching this state for that peer. For other
peers wg_packet_rx_poll does get called normally.
- Commit db9ae3b ("wireguard: device: enable threaded NAPI")
switched WireGuard to threaded NAPI by default. The default has
not been changed for triggering the issue, neither did CPU
hotplugging occur (i.e. 5bd8de2 ("wireguard: queueing: always
return valid online CPU in wg_cpumask_choose_online()")).
- The issue has been observed with stable kernels of v5.15 as well as
v6.1. It was reported to us that v5.10 stable is working fine, and
no report on v6.6 stable either (somewhat related discussion in [0]
though).
- In the WireGuard driver the only material difference between v5.10
stable and v5.15 stable is the switch to threaded NAPI by default.
[0] https://lore.kernel.org/netdev/CA+wXwBTT74RErDGAnj98PqS=wvdh8eM1pi4q6tTdExtjnokKqA@mail.gmail.com/
Breakdown of the problem:
1) skbs arriving for decryption are enqueued to the peer->rx_queue in
wg_packet_consume_data via wg_queue_enqueue_per_device_and_peer.
2) The latter only moves the skb into the MPSC peer queue if it does
not surpass MAX_QUEUED_PACKETS (1024) which is kept track in an
atomic counter via wg_prev_queue_enqueue.
3) In case enqueueing was successful, the skb is also queued up
in the device queue, round-robin picks a next online CPU, and
schedules the decryption worker.
4) The wg_packet_decrypt_worker, once scheduled, picks these up
from the queue, decrypts the packets and once done calls into
wg_queue_enqueue_per_peer_rx.
5) The latter updates the state to PACKET_STATE_CRYPTED on success
and calls napi_schedule on the per peer->napi instance.
6) NAPI then polls via wg_packet_rx_poll. wg_prev_queue_peek checks
on the peer->rx_queue. It will wg_prev_queue_dequeue if the
queue->peeked skb was not cached yet, or just return the latter
otherwise. (wg_prev_queue_drop_peeked later clears the cache.)
7) From an ordering perspective, the peer->rx_queue has skbs in order
while the device queue with the per-CPU worker threads from a
global ordering PoV can finish the decryption and signal the skb
PACKET_STATE_CRYPTED out of order.
8) A situation can be observed that the first packet coming in will
be stuck waiting for the decryption worker to be scheduled for
a longer time when the system is under pressure.
9) While this is the case, the other CPUs in the meantime finish
decryption and call into napi_schedule.
10) Now in wg_packet_rx_poll it picks up the first in-order skb
from the peer->rx_queue and sees that its state is still
PACKET_STATE_UNCRYPTED. The NAPI poll routine then exits e
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
dm: fix unlocked test for dm_suspended_md
The function dm_blk_report_zones tests if the device is suspended with
the "dm_suspended_md" call. However, this function is called without
holding any locks, so the device may be suspended just after it.
Move the call to dm_suspended_md after dm_get_live_table, so that the
device can't be suspended after the suspended state was tested. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL
The SCTP_SENDALL path in sctp_sendmsg() iterates ep->asocs with
list_for_each_entry_safe(), which caches the next entry in @tmp before
the loop body runs. The body calls sctp_sendmsg_to_asoc(), which may
drop the socket lock inside sctp_wait_for_sndbuf().
While the lock is dropped, another thread can SCTP_SOCKOPT_PEELOFF the
association cached in @tmp, migrating it to a new endpoint via
sctp_sock_migrate() (list_del_init() + list_add_tail() to
newep->asocs), and optionally close the new socket which frees the
association via kfree_rcu(). The cached @tmp can also be freed by a
network ABORT for that association, processed in softirq while the
lock is dropped.
sctp_wait_for_sndbuf() revalidates @asoc (the current entry) on re-lock
via the "sk != asoc->base.sk" and "asoc->base.dead" checks, but nothing
revalidates @tmp. After a successful return, the iterator advances to
the stale @tmp, yielding either a use-after-free (if the peeled socket
was closed) or a list-walk onto the new endpoint's list head (type
confusion of &newep->asocs as a struct sctp_association *).
Both are reachable from CapEff=0; the type-confusion path gives
controlled indirect call via the outqueue.sched->init_sid pointer.
Fix by re-deriving @tmp from @asoc after sctp_sendmsg_to_asoc()
returns. @asoc is known to still be on ep->asocs at that point: the
only callers that list_del an association from ep->asocs are
sctp_association_free() (which sets asoc->base.dead) and
sctp_assoc_migrate() (which changes asoc->base.sk), and
sctp_wait_for_sndbuf() checks both under the lock before any
successful return; a tripped check propagates as err < 0 and the loop
bails before the re-derive.
The SCTP_ABORT path in sctp_sendmsg_check_sflags() returns 0 and the
loop hits 'continue' before sctp_sendmsg_to_asoc() is ever called, so
the @tmp cached by list_for_each_entry_safe() still covers the
lock-held free that ba59fb027307 ("sctp: walk the list of asoc
safely") was added for. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: check if target buffer list is still legacy on recycle
There's a gap between when the buffer was grabbed and when it
potentially gets recycled, where if the list is empty, someone could've
upgraded it to a ring provided type. This can happen if the request
is forced via io-wq. The legacy recycling is missing checking if the
buffer_list still exists, and if it's of the correct type. Add those
checks. |
| In the Linux kernel, the following vulnerability has been resolved:
openvswitch: defer tunnel netdev_put to RCU release
ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already
detached the device. Dropping the netdev reference in destroy can race
with concurrent readers that still observe vport->dev.
Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let
vport_netdev_free() drop the reference from the RCU callback, matching
the non-tunnel destroy path and avoiding additional synchronization
under RTNL. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: unconditionally bump set->nelems before insertion
In case that the set is full, a new element gets published then removed
without waiting for the RCU grace period, while RCU reader can be
walking over it already.
To address this issue, add the element transaction even if set is full,
but toggle the set_full flag to report -ENFILE so the abort path safely
unwinds the set to its previous state.
As for element updates, decrement set->nelems to restore it.
A simpler fix is to call synchronize_rcu() in the error path.
However, with a large batch adding elements to already maxed-out set,
this could cause noticeable slowdown of such batches. |
| In the Linux kernel, the following vulnerability has been resolved:
bonding: annotate data-races around slave->last_rx
slave->last_rx and slave->target_last_arp_rx[...] can be read and written
locklessly. Add READ_ONCE() and WRITE_ONCE() annotations.
syzbot reported:
BUG: KCSAN: data-race in bond_rcv_validate / bond_rcv_validate
write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 1:
bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335
bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533
__netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039
__netif_receive_skb_one_core net/core/dev.c:6150 [inline]
__netif_receive_skb+0x59/0x270 net/core/dev.c:6265
netif_receive_skb_internal net/core/dev.c:6351 [inline]
netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410
...
write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 0:
bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335
bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533
__netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039
__netif_receive_skb_one_core net/core/dev.c:6150 [inline]
__netif_receive_skb+0x59/0x270 net/core/dev.c:6265
netif_receive_skb_internal net/core/dev.c:6351 [inline]
netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410
br_netif_receive_skb net/bridge/br_input.c:30 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
...
value changed: 0x0000000100005365 -> 0x0000000100005366 |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (w83791d) Convert macros to functions to avoid TOCTOU
The macro FAN_FROM_REG evaluates its arguments multiple times. When used
in lockless contexts involving shared driver data, this leads to
Time-of-Check to Time-of-Use (TOCTOU) race conditions, potentially
causing divide-by-zero errors.
Convert the macro to a static function. This guarantees that arguments
are evaluated only once (pass-by-value), preventing the race
conditions.
Additionally, in store_fan_div, move the calculation of the minimum
limit inside the update lock. This ensures that the read-modify-write
sequence operates on consistent data.
Adhere to the principle of minimal changes by only converting macros
that evaluate arguments multiple times and are used in lockless
contexts. |
| Time-of-check time-of-use (toctou) race condition in Windows Projected File System allows an authorized attacker to perform tampering locally. |
| An issue in gnutls v.3.8.13 allows an attacker to obtain sensitive information via failing to reject end-entity X.509 certificates that contain a contradictory combination of Key Usage (KU) and Extended Key Usage (EKU) |
| Time-of-check time-of-use (toctou) race condition in Reliable Multicast Transport Driver (RMCAST) allows an authorized attacker to elevate privileges locally. |
| Use after free in Windows Kernel-Mode Drivers allows an authorized attacker to elevate privileges locally. |
| Time-of-check time-of-use (toctou) race condition in Windows Error Reporting allows an authorized attacker to elevate privileges locally. |
| Time-of-check time-of-use (toctou) race condition in Windows Setup Files Cleanup allows an authorized attacker to elevate privileges locally. |
