| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
virt: acrn: Fix irqfd use-after-free during eventfd shutdown
acrn_irqfd_deassign() and the eventfd EPOLLHUP wakeup can race and free
the same struct hsm_irqfd:
CPU0 CPU1
---- ----
eventfd_release()
wake_up_poll(EPOLLHUP)
hsm_irqfd_wakeup()
queue_work(&irqfd->shutdown)
acrn_irqfd_deassign()
hsm_irqfd_shutdown()
list_del_init()
eventfd_ctx_remove_wait_queue()
eventfd_ctx_put()
kfree(irqfd)
hsm_irqfd_shutdown_work()
container_of(work, ..., shutdown)
irqfd->vm <-- use-after-free
The deassign path freed the irqfd while a shutdown work item was
already queued by EPOLLHUP (or vice versa), so the work item could
resurrect a dangling pointer through container_of().
Switch to the lifetime model used by KVM irqfds:
- Deassign/deinit only deactivate the irqfd: remove it from vm->irqfds
under irqfds_lock and queue the cleanup work.
- hsm_irqfd_shutdown_work() becomes the sole owner that unhooks the
eventfd waitqueue entry, drops the eventfd reference and frees the
irqfd.
- A new HSM_IRQFD_FLAG_SHUTDOWN bit guarded by test_and_set_bit()
ensures the cleanup work is queued at most once, no matter how many
of {EPOLLHUP, deassign, deinit} fire concurrently. This is safe to
call from the waitqueue callback, which runs with wqh->lock held and
IRQs disabled and therefore cannot take irqfds_lock.
- acrn_irqfd_deassign() flushes vm->irqfd_wq before returning so the
eventfd is fully detached on return. acrn_irqfd_deinit() deactivates
every irqfd, flushes the workqueue and only then destroys it, so no
path can queue_work() onto a torn-down workqueue.
- acrn_irqfd_assign() now installs the eventfd waitqueue entry and
publishes the irqfd to vm->irqfds under irqfds_lock, so the irqfd is
never visible to deassign/deinit before its waitqueue entry is in
place, and any EPOLLHUP that fires in the assign window queues
cleanup work that blocks on irqfds_lock until publication is done. |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: Fix potential UAF in pec_store
Sashiko reports:
In pec_store(), a guard(mutex)(&hwdev->lock) is taken. If the chip write
operation returns an error other than -EOPNOTSUPP, the code jumps to the
put label, which calls put_device(hdev). If this drops the final reference,
the device is freed. When the function then returns, the guard cleanup
function runs and attempts to unlock the freed mutex.
Use scoped_guard() instead of guard() to avoid the problem. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put
In mlx5_eswitch_termtbl_put(), the zero-ref cleanup check reads
tt->ref_count after termtbl_mutex has been released. Two concurrent
callers on the same mlx5_termtbl_handle race: one decrements ref_count
to zero, removes the hash entry, and calls kfree(tt) while the other
has already dropped the mutex and is about to evaluate
if (!tt->ref_count), producing a use-after-free.
Fix this by capturing the result of the decrement into a stack-local
last variable before dropping the mutex. The cleanup decision is now
made entirely under termtbl_mutex, and tt is not touched after
kfree. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb
BT enable fails intermittently with -ETIMEDOUT (-110). The kernel log
shows the HCI Read Local Version command was sent and the firmware
replied with status 0x00 (logged by hci_req_cmd_complete() BT_DBG),
but the waiter in __hci_cmd_sync_sk() never woke up and timed out
after 10 s:
bluetooth hci0: Opcode 0xfc00 // __hci_cmd_sync_sk
bluetooth hci0: opcode 0xfc00 plen 1 // hci_cmd_sync_add
bluetooth hci0: skb len 4 // hci_cmd_sync_alloc
bluetooth hci0: length 1 // hci_req_sync_run
Bluetooth: hci0 cmd_cnt 1 cmd queued 1 // hci_cmd_work
Bluetooth: hci0 type 1 len 4 // hci_send_frame
Bluetooth: opcode 0xfc00 status 0x00 // hci_req_cmd_complete
<-- req_skb NULL: req_complete_skb not set,
hci_cmd_sync_complete() never called,
req_status stays HCI_REQ_PEND -->
<-- 10 s later: wait_event_interruptible_timeout expires -->
bluetooth hci0: end: err -110 // __hci_cmd_sync_sk
The root cause is that hci_send_cmd_sync() clones the sent command
into hdev->req_skb so that hci_req_cmd_complete() can locate the
registered completion callback. Under memory pressure this
skb_clone() fails, leaving hdev->req_skb NULL. The firmware reply
is received and processed, but hci_req_cmd_complete() finds NULL
req_skb, so hci_cmd_sync_complete() is never called, req_status
stays HCI_REQ_PEND, and the waiter times out with -ETIMEDOUT.
req_skb is only used to read bt_cb(skb)->hci callbacks and opcode --
it is never modified. Replace skb_clone() with skb_get(), which
simply increments the reference count of hdev->sent_cmd without
allocating new memory and therefore cannot fail.
This issue was first observed as a use-after-free in ttyport_close()
when ttyport_open() failed, which was investigated in an earlier
patch series [1]. That investigation led to the discovery of the
true root cause described above.
[1] https://lore.kernel.org/all/20250430111617.1151390-1-quic_cxin@quicinc.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
cdx: Fix double free when sysfs file creation fails
In cdx_create_res_attr(), if sysfs_create_bin_file() fails, the code
frees res_attr but doesn't set cdx_dev->res_attr[num] to NULL. This
leaves a dangling pointer in the array. Then cdx_destroy_res_attr()
frees the already-freed memory. Fix the double free by initializing
cdx_dev->res_attr[num] after sysfs_create_bin_file() completes. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF
A previous commit protected against races between ptdump and CPA collapse,
however one still exists between attribute changes and collapse as reported
by Denis V. Lunev (linked).
When an attribute change arises, a lockless page table walker obtains a PTE
entry, which is later written to via set_pte_atomic():
...
-> change_page_attr_set_clr()
-> __change_page_attr_set_clr()
-> __change_page_attr()
-> _lookup_address_cpa()
-> lookup_address_in_pgd_attr()
-> [ lockless page table walker ]
-> set_pte_atomic()
There is nothing preventing a concurrent CPA collapse which can free the
PTE that was retrieved here, resulting in a use-after-free.
With the mmap write lock taken on init_mm over CPA collapse, resolve this
race by acquiring an mmap read lock on init_mm over
__change_page_attr_set_clr().
This locks across the whole operation over which the walk and the PTE
entry write occurs, solving the race.
It is safe to do this here, as no spinlocks are held upon entry to
__change_page_attr_set_clr().
However, the lock must not be held over an allocation, as allocation can
trigger reclaim and shrinkers may call into CPA recursively, making
deadlocks possible (init_mm -> ... -> fs_reclaim -> init_mm).
A page table is allocated when a huge page needs to be split:
-> change_page_attr_set_clr()
-> __change_page_attr_set_clr()
-> __change_page_attr()
-> split_large_page()
[ pagetable_alloc() ]
-> __split_large_page()
Avoid deadlocks by dropping the mmap lock across pagetable_alloc() in
split_large_page() and track whether this is needed by adding a new
'init_mm_read_locked' flag to struct cpa_data.
This is safe as __split_large_page() (called with locks re-established)
revalidates that the page table entry is the same as it was prior to the
locks being dropped and __change_page_attr() repeats the entire page table
walk whenever a split occurs, so concurrent split and collapse are
accounted for.
Concurrent ptdump is also safe as the lock is only dropped over page table
allocation during which time the page table has not yet been modified.
The CPA_COLLAPSE flag is only set by set_memory_rox(), which exclusively
operates upon vmalloc ranges, and on x86 only within the module mapping
space.
This is important, because some callers directly invoke
__change_page_attr_set_clr(), bypassing this lock. However, none of these
operate within the module mapping space.
* cpa_process_alias() - a recursive helper called by
__change_page_attr_set_clr().
* __set_memory_enc_pgtable() - operates on the direct mapping and (via
__vmbus_establish_gpadl()) the vmalloc mapping space.
* __set_pages_[n]p() - called by set_direct_map_[invalid, default,
valid]_noflush(), __kernel_map_pages() - operates on the direct map.
* kernel_[un]map_pages_in_pgd() - operates on EFI ranges.
This work is based upon Denis V. Lunev's excellent analysis of the bug
with gratitude.
[ dhansen: move to imperative voice in changelog ] |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: pin DFS superblock in iterator callback
tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()
takes its active reference only after iterate_supers_type() has dropped
s_umount and its passive reference. Concurrent DFS automount expiry can
therefore free the superblock before cifs_sb_active() uses it.
A deterministic KASAN test reproduces the race as:
BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80
The same test passes with this change applied.
Take the active reference in the callback while iterate_supers_type()
still holds s_umount shared. cifs_put_tcp_super() remains the matching
release. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: Decoupling ep1_in_urb in caiaq dev
The epq_in_urb object belonging to the caiaq device is coupled within
the struct snd_usb_caiaqdev. After usb_submit_urb(epq_in_urb, GFP_KERNEL)
executes successfully, epq_in_urb is successfully added to the urbp_list
queue of the dummy HCD driver (userspace specifies dummy_hcd as the HCD
layer driver for the caiaq USB device).
When init_card() calls snd_usb_caiaq_send_command() which subsequently
fails due to a timeout, and proceeds to call snd_card_free() to release
the card, the embedded ep1_in_urb object is also freed. When the dummy
HCD driver detects that the URB has been unlinked, it returns the URB
(by usb_hcd_giveback_urb()), which triggers [1].
Decouple the ep1_in_urb object from the struct snd_usb_caiaqdev and switch
to using a pointer instead. Separately allocate and manage the memory for
ep1_in_urb to prevent the release of the snd_card memory object from
interfering with it.
midi_out_urb has the same issue as ep1_in_urb and is handled in the same
way.
[1]
BUG: KASAN: slab-use-after-free in usb_free_urb+0x24/0x120 drivers/usb/core/urb.c:96
Write of size 4 at addr ffff88803cee1050 by task ktimers/1/29
Call Trace:
usb_free_urb+0x24/0x120 drivers/usb/core/urb.c:96
dummy_timer+0xaac/0x4d50 drivers/usb/gadget/udc/dummy_hcd.c:2019
__run_hrtimer kernel/time/hrtimer.c:2067 [inline]
__hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2124
hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2141
Allocated by task 36:
snd_card_new+0x7b/0x110 sound/core/init.c:184
create_card sound/usb/caiaq/device.c:429 [inline]
snd_probe+0x236/0x1af0 sound/usb/caiaq/device.c:544
Freed by task 36:
snd_card_free_when_closed sound/core/init.c:630 [inline]
snd_card_free+0x138/0x1d0 sound/core/init.c:662
snd_probe+0x162b/0x1af0 sound/usb/caiaq/device.c:553 |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: E-Switch, prevent mc_list repopulation during vport disable
In mlx5_esw_vport_disable(), move esw_apply_vport_rx_mode() ahead
of esw_vport_change_handle_locked() so vport->allmulti_rule is
NULL before the change handler observes it.
During FW-fatal recovery the disable runs while dev->state ==
INTERNAL_ERROR. The promisc query inside esw_update_vport_rx_mode()
fails and returns early, leaving vport->allmulti_rule intact, so
esw_update_vport_mc_promisc() runs and adds MLX5_ACTION_ADD entries
to vport->mc_list whose flow rules are then installed in the FDB
by esw_add_mc_addr(). esw_destroy_legacy_table() tears down the
FDB with those refs still held, corrupting the sub-tree and
leaving dangling flow_rule pointers in vport->mc_list.
Two-stage failure on `echo 1 > /sys/bus/pci/devices/<bdf>/reset`:
refcount_t: underflow; use-after-free.
tree_put_node+0xef/0x110 [mlx5_core]
clean_tree+0x44/0xd0 [mlx5_core] (x5)
mlx5_fs_core_cleanup+0x57/0x1c0 [mlx5_core]
mlx5_unload+0x65/0xd0 [mlx5_core]
... mlx5_health_try_recover
BUG: unable to handle page fault for address: 0000000003000055
down_write+0x1c/0x60
mlx5_del_flow_rules+0x33/0x1f0 [mlx5_core]
esw_del_mc_addr+0x7b/0x170 [mlx5_core]
esw_apply_vport_addr_list+0x56/0xf0 [mlx5_core]
esw_vport_change_handle_locked+0x28b/0x310 [mlx5_core]
mlx5_esw_vport_enable+0x270/0x4a0 [mlx5_core]
... mlx5_load ... mlx5_health_try_recover
esw_apply_vport_rx_mode(false, false) clears vport->allmulti_rule
via its local state machine even when the FW del fails. With the
rule NULL the !IS_ERR_OR_NULL(allmulti_rule) gate in the change
handler closes, no rules are installed during disable, and the
reload starts with a clean mc_list. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix use-after-free race in sample_restore_put()
Concurrent teardown of TC sample rules sharing the same restore
context may re-read restore->count after dropping restore_lock.
At that point another thread may already have completed cleanup and
freed the restore object.
Use the result of the refcount decrement while holding restore_lock to
determine whether cleanup is needed. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Skip vport under deletion in report ID acquisition
qla24xx_report_id_acquisition() format-1 handling walks ha->vp_list under
vport_slock, takes a vref_count on the matching vport and calls
qla_update_host_map() to register its port id.
A vport teardown via qla24xx_vport_delete() sets VPORT_DELETE, then
qla24xx_disable_vp() removes the vport from the host_map btree and zeroes
vha->d_id (RESET_AL_PA). The vport is only unlinked from vp_list later,
in qla24xx_deallocate_vp_id(), which clears vp_map[idx] (RESET_VP_IDX)
but does not touch host_map. In the window in between, report ID
acquisition can still find the vport on vp_list and call
qla_update_host_map(); with d_id already zeroed it takes the
btree_insert32() path and re-inserts the dying vport into host_map.
Nothing cleans that entry afterwards, so once scsi_host_put() frees the
vha a later host_map lookup dereferences freed memory.
Skip a vport that has VPORT_DELETE set before taking the reference, so it
is neither re-registered nor scheduled for DPC re-registration. This
mirrors the existing guard in qla2x00_alert_all_vps(). |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: reject dynamic fdb entries that reference a nexthop id
The commit cited in the Fixes tag allowed VXLAN FDB entries to point to
FDB nexthops so that overlay traffic could be load balanced across
multiple VTEPs. Such entries can only be configured from user space,
cannot be learned and cannot roam. They only make sense with a user space
control plane such as E-VPN where data plane learning is disabled.
Despite that, the VXLAN driver does not currently prevent such entries
from being configured with the "dynamic" flag. The per-nexthop FDB list
is only protected by the per-device hash lock, which is not sufficient
when two VXLAN devices point to the same FDB nexthop and therefore share
the list. Aging runs in softirq context without RTNL, so an entry deleted
by one device can race with an addition or deletion from the other,
leading to list corruption:
list_del corruption. next->prev should be ffff8881069d9548, but was
dead000000000122. (next=ffff8881069d9448)
WARNING: CPU: 0 PID: 90 at lib/list_debug.c:65
__list_del_entry_valid_or_report+0x1aa/0x210
...
vxlan_fdb_destroy+0x5b8/0xad0
vxlan_cleanup+0x328/0x450
call_timer_fn+0x2a/0x1c0
run_timer_softirq+0x18c/0x210
BUG: KASAN: slab-use-after-free in vxlan_fdb_destroy
Fix this by rejecting the bogus configuration of dynamic FDB entries that
point to FDB nexthops, both when created and when an existing entry is
updated. As such, the per-nexthop FDB list is only ever mutated under the
RTNL lock. Add test cases to make sure that this does not regress in the
future. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/ism: folio_put() after error
dmb->cpu_addr was allocated via folio_alloc(). Use folio_put() instead of
kfree() in the error exit of ism_alloc_dmb() to avoid slab allocator
corruption.
While at it, reset dmb->cpu_addr after folio_put to avoid unintentional UAF
by future callers. |
| In the Linux kernel, the following vulnerability has been resolved:
mac802154: fix use-after-free of sdata via queued RX frames
The RX softirq producer ieee802154_subif_frame() queues received beacon
and MAC-command frames onto local->rx_beacon_list / rx_mac_cmd_list and
schedules a process-context worker, storing a raw mac_pkt->sdata (and
skb->dev == sdata->dev) with neither a reference nor any locking:
- the lists have no lock: the softirq producer list_add_tail()s while the
mac_wq worker list_del()s, so sibling interfaces on the same phy corrupt
the list;
- the workers dereference the interface after it may have been freed.
mac802154_rx_mac_cmd_worker() touches mac_pkt->sdata directly, and
mac802154_rx_beacon_worker() -> mac802154_process_beacon() dereferences
skb->dev (== sdata->dev). Removing an interface frees its sdata
(netdev_priv) while a queued frame still points at it, so a later worker
run is a use-after-free.
Reproduced under KASAN by flooding a victim interface with MAC command
frames and removing it (the beacon path is the same class via skb->dev):
BUG: KASAN: slab-use-after-free in mac802154_rx_mac_cmd_worker+0x463/0x630 [mac802154]
Read of size 4 at addr ffff888002f9ea18 by task kworker/u8:1/31
Workqueue: phy0-mac-cmds mac802154_rx_mac_cmd_worker [mac802154]
Call Trace:
mac802154_rx_mac_cmd_worker+0x463/0x630 [mac802154]
process_one_work+0x611/0xe80
worker_thread+0x52e/0xdc0
kthread+0x30c/0x630
ret_from_fork+0x2fd/0x3e0
Fix both lists together:
- add local->rx_lock and take it around every list access: the softirq
producer (plain spin_lock, softirq context) and the workers and flush
(spin_lock_bh, process context);
- pin the interface for the lifetime of a queued frame with
netdev_hold()/netdev_put(), so the worker can safely dereference sdata /
skb->dev even while the interface is being removed;
- dequeue under the lock at the head and loop-drain the whole list in the
workers (they previously processed one frame per run and relied on a
later enqueue to drain the rest);
- drop not-yet-started frames of an interface before it is unregistered,
from ieee802154_if_remove() (after the RCU grace period) and from the
ieee802154_remove_interfaces() loop -- the latter is the whole-phy
teardown path, which does not go through ieee802154_if_remove().
An in-flight worker that already dequeued a frame keeps its own netdev
reference; unregister_netdevice() then waits it out in netdev_run_todo(),
which runs at rtnl_unlock() (rtnl released) and after the interface has
been closed, so it does not pin rtnl. A worker blocked in an association
TX only delays that one interface's unregister (the usual "waiting for %s
to become free"), it does not hold rtnl. netdev_hold() is used for this
reason instead of a cancel_work_sync() under rtnl, which would block on
the worker's unbounded MLME TX wait via ieee802154_sync_queue().
The mac-command worker additionally skips processing for a stopped
interface (ieee802154_sdata_running()), avoiding a needless association
response during teardown. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/mm/pat: Allocate split page tables as kernel page tables
A PTE is allocated directly without going through the standard page table
allocation routines (such as pte_alloc_one_kernel()) when the CPA code
splits a large page (__split_large_page()).
This means the page table constructor is never called nor is the page table
marked as a kernel page table.
The former results in the folio associated with the page table not being
marked as a page table (__pagetable_ctor() is never called thus neither is
__folio_set_pgtable()) nor are statistics updated to reflect
it (lruvec_stat_add_folio() is never called).
The latter issue of failing to mark the page table as a kernel page
table (ptdesc_set_kernel() is never called) is far more problematic.
Since commit:
5ba2f0a15564 ("mm: introduce deferred freeing for kernel page tables")
kernel page table freeing has been batched and since the
subsequent commit:
e37d5a2d60a3 ("iommu/sva: invalidate stale IOTLB entries for kernel address space")
IOTLB cache entries for kernel page tables have been invalidated upon
being freed.
Since split page tables are freed without this invalidation, the IOTLB
can contain stale entries for them.
Resolve the issue by using the ordinary PTE allocation API at split time.
This results in these kernel page tables invoking a page table constructor,
and thus requires a page table destructor.
Destructors are not always present, like for early allocated direct map
page tables). Conditionally call pagetable_dtor_free() if the PG_table
folio flag for the ptdesc is set, otherwise we free the page table via
pagetable_free().
Regardless of which path is taken page tables marked as kernel page tables,
which now includes split page tables, take the correct route through
pagetable_free_kernel().
There is a user-visible side effect in that split page tables will appear
in nr_page_table_pages in /proc/vmstat (as do other kernel page tables
allocated after early boot), however this is a positive change.
This issue started being markedly problematic after commit:
5ba2f0a15564 ("mm: introduce deferred freeing for kernel page tables")
so choose this as the Fixes target.
[ dhansen: rephrase in imperative mood ] |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Unlink NVMe unsol ctx before freeing on LS reject error
qla_nvme_xmt_ls_rsp() obtains uctx, which was linked into
fcport->unsol_ctx_head by qla2xxx_process_purls_iocb() and is still linked
when the NVMe transport calls back to transmit the LS response. On the
error (out:) path the function frees uctx with kfree() but never removes
it from the list. This leaves a freed node in fcport->unsol_ctx_head: the
next list_add_tail() for that fcport writes through the freed node, and a
subsequent list_del() can corrupt the list or panic.
Unlink uctx with list_del() before kfree() on the error path, matching the
other free sites in qla_nvme_release_lsrsp_cmd_kref() and
qla2xxx_process_purls_pkt(). qla2x00_rel_sp() in the failure path only
returns the SRB to its pool and does not invoke sp->put_fn, so the out:
path is the sole free and uctx is always still linked there. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix use-after-free of qpair work on queue teardown
The response queue MSI-X handler qla2xxx_msix_rsp_q() schedules
qla_do_work() via queue_work(ha->wq, &qpair->q_work). qla_do_work()
dereferences the qpair (vha, rsp) and takes qpair->qp_lock.
During teardown, qla2xxx_delete_qpair() deletes the response queue, which
calls free_irq() in qla25xx_free_rsp_que(), and then frees the queue and
the qpair. free_irq() waits for running hardirq handlers but does not
cancel work already placed on ha->wq. A still-pending q_work then runs
qla_do_work() against the freed qpair and response queue, causing a
use-after-free. This is especially likely during full adapter teardown,
where destroy_workqueue(ha->wq) forces pending work to run after the queue
pairs have been freed.
Flush the work item with cancel_work_sync() in qla25xx_free_rsp_que()
after free_irq() has released the interrupt (so no new work can be
queued) and before the response queue and qpair memory are freed (so the
flushed handler still sees valid memory). Guard on rsp->qpair and ha->wq
to match the INIT_WORK() condition and avoid operating on an
uninitialized work_struct. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: safely drain sessions during logoff
SMB3 multichannel allows requests for one session to run on multiple
connections. Wait for all channels bound to a session before freeing
shared session objects.
A deferred byte-range lock remains counted as a running request and only
wakes when its file closes. Wake blocked locks during the drain without
unpublishing or modifying their file objects. Synchronous CANCEL requests
must invoke their cancellation callback to wake pending operations, while
CHANGE_NOTIFY completion remains specific to the asynchronous path.
Serialize session teardown with channel registration and previous-session
cleanup, and use atomic work-state transitions so LOGOFF, CANCEL, and
connection teardown invoke cancellation callbacks only once. |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()
vxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every
MDBE_ATTR_SRC_LIST member, accepts the all-zeros address.
A source list is only accepted on a (*, G) entry, whose source is the
all-zeros address, and for each member of the list an (S, G) entry is
derived from it by substituting the source. Entries are keyed by a plain
memcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present
and holds the all-zeros address and the source list holds it as well, the
derived (S, G) key is byte-identical to the (*, G) key and resolves to the
same entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is
then left with a zero address family.
vxlan_mdb_remote_src_del() removes the forwarding entry of a source before
freeing the source entry:
vxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr);
vxlan_mdb_remote_src_entry_del(ent);
With the keys aliased, the first call deletes the remote of the entry that
owns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second
call then runs on the freed entry, and its hlist_del() reads ->pprev and
->next out of it and writes through them.
Adding the (*, G) entry with NLM_F_REPLACE and no source list marks the
all-zeros source for deletion and reaches this from the sweep at the end
of vxlan_mdb_remote_srcs_replace().
BUG: KASAN: slab-use-after-free in __vxlan_mdb_add+0x1cd/0xd70
Read of size 8 at addr ffff888102852500 by task poc/84
__vxlan_mdb_add+0x1cd/0xd70
vxlan_mdb_add+0xc0/0x140
rtnl_mdb_add+0x157/0x2a0
rtnetlink_rcv_msg+0x207/0x5a0
Allocated by task 84:
__kmalloc_cache_noprof+0x153/0x360
vxlan_mdb_remote_srcs_add+0x2eb/0x440
__vxlan_mdb_add+0x803/0xd70
Freed by task 84:
kfree+0x14c/0x3b0
vxlan_mdb_remote_del+0x129/0x1a0
__vxlan_mdb_del+0x4f/0xe0
vxlan_mdb_remote_src_fwd_del.isra.0+0x162/0x1b0
__vxlan_mdb_add+0x1c5/0xd70
The MDB operations are netns-scoped, so an unprivileged user can perform
them in a new user and network namespace.
Reject the all-zeros address in vxlan_mdb_is_valid_source(), which covers
both call sites. A (*, G) entry is expressed by omitting the source, so
nothing legitimate is refused.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix incorrect free in candidate cleanup in afs_lookup_server()
Fix afs_lookup_server() to not free an existing server's endpoint state
when cleaning up a candidate server. The candidate record doesn't have an
endpoint state yet at this point, so the free for that can just be removed. |
