| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: atmel-mci: Fix use-after-free in atmci_remove due to race condition
In atmci_probe, &host->bh_work is bound with atmci_work_func, and
atmci_interrupt, atmci_timeout_timer and atmci_dma_complete can all
queue this work on system_bh_wq.
If we remove the module, atmci_remove makes cleanup and the memory
allocated for host with devm_kzalloc() is released after the remove
callback returns, while the work mentioned above may still be pending
or running. The sequence of operations that may lead to a UAF bug is
as follows:
CPU0 CPU1
| atmci_interrupt
| queue_work(system_bh_wq,
| &host->bh_work)
atmci_remove |
atmci_cleanup_slot(...) |
atmci_writel(host, ATMCI_IDR, ~0UL) |
timer_delete_sync(&host->timer) |
dma_release_channel(host->dma.chan) |
free_irq(platform_get_irq(pdev, 0), host) |
| atmci_work_func
| // use host
// devm resources released after |
// remove returns, host is freed |
| // use host (use-after-free)
Fix it by canceling the work after all the sources that can schedule
it (IRQ handler, timeout timer and DMA completion callback) have been
stopped, and before proceeding with the remaining cleanup in
atmci_remove. |
| In the Linux kernel, the following vulnerability has been resolved:
net/x25: fix use-after-free of the socket by its timers
The x25 timers are armed with mod_timer() and cancelled with
timer_delete(), so a pending timer holds no reference on the socket and a
cancel does not wait for a callback already running on another CPU.
x25_heartbeat_expiry() also rearms unconditionally, so it can reinstall
sk->sk_timer after __x25_destroy_socket() has passed its cancel point.
The following __sock_put() frees the socket while the timer is still
queued, and the next expiry uses freed memory. KASAN reports a
slab-use-after-free on the kmalloc-2k object freed by close().
timer_delete_sync() cannot be used here: x25_heartbeat_expiry() and
x25_timer_expiry() both reach the cancels from inside the timer they
would wait on, through __x25_destroy_socket() and x25_disconnect().
Arm the timers with sk_reset_timer() and cancel them with sk_stop_timer()
so that an armed timer owns a reference, and release it in both expiry
handlers. Rearm the heartbeat only while sk_hashed(sk) is still true,
since __x25_destroy_socket() unlinks the socket before dropping it. Arm
the deferred destroy timer the same way and drop its reference in
x25_destroy_timer().
Reproduced on net with KASAN, with the heartbeat period shortened so the
window recurs. With this patch the reproducer no longer triggers a
report and /proc/net/x25 drains.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Fix advertising data UAFs
hci_find_adv_instance() returns an adv_info pointer that is valid only
while hdev->lock is held. The advertising command-sync paths perform
instance lookups without that lock and, in some cases, retain the pointer
while waiting for a controller response.
An advertising termination event can therefore interleave as follows:
hci_cmd_sync_work hci_rx_work
hci_find_adv_instance()
__hci_cmd_sync_status()
wait for controller reply hci_dev_lock()
hci_remove_adv_instance()
kfree(adv)
adv->scan_rsp_changed = false
KASAN reported:
BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
hci_schedule_adv_instance_sync+0x390/0x4c0
hci_cmd_sync_work+0x173/0x300
Allocated by task 87:
hci_add_adv_instance+0x538/0xac0
add_advertising+0x885/0x1160
Freed by task 89:
kfree+0x131/0x3c0
hci_remove_adv_instance+0x1d8/0x3b0
hci_le_ext_adv_term_evt+0x17b/0x730
Protect the instance lookup and payload construction in the extended
advertising, scan response, and periodic advertising data paths. Snapshot
the advertising parameters under hdev->lock, but release the lock before
waiting for the controller.
Clear advertising-data dirty bits before issuing their commands and
restore them after a failure using a fresh lookup. Likewise, update the
reported transmit power through a fresh lookup after the parameter command
completes. No adv_info pointer then survives an HCI command wait. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: avoid UAF on sc->tempip in xrep_tempfile_create
LOLLM noticed a potential UAF if the tempfile creation code fails after
it set sc->tempip. Fix that. |
| Use after free in DOM in Google Chrome prior to 151.0.7922.173 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High) |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: prevent in6_dev_get() from resurrecting inet6_dev
in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally
increments its refcount. Device teardown can clear the pointer and drop
the last reference between these operations. The increment then
resurrects an object whose RCU free has already been queued, so callers
can use it after it is freed.
Use refcount_inc_not_zero() and return NULL when the object has already
reached zero. RCU keeps the memory accessible through the attempted
reference acquisition, and a successful increment pins the object for
the caller.
An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)
kernel reproduced the invalid reference acquisition as UID 1000:
refcount_t: addition on 0; use-after-free.
ip6_mc_source+0xef4/0x17e0
It was followed by the corresponding reference underflow in
ip6_mc_source(). The supplied trace from the same unpatched revision
additionally shows the access after the RCU read-side section ends:
BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0
Write of size 8 at addr ffff888015b50240 by task poc/1219
Bug found and triaged by OpenAI Security Research and
validated by Trail of Bits. |
| In the Linux kernel, the following vulnerability has been resolved:
serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ
The RS485 trigger hrtimers are embedded in the devm-managed port and can
fire after it is freed. The IRQ handler can arm a timer, so free the IRQ
first and then cancel both timers.
Complete the RS485 stop without arming a timer, and cancel the timers
in remove() for the suspend-then-unbind path, where shutdown is not
called.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/vmalloc: acquire init_mm lock on huge vmap to avoid ptdump UAF
Patch series "mm: fix UAF caused by race between ptdump and vmap pgtable
freeing", v6.
Kernel page table walkers fall into two broad categories - those ranges
where no exclusion is required via walk_kernel_page_table_range_lockless()
and those where exclusion is required via walk_kernel_page_table_range()
or walk_page_range_debug().
The former category is used only by arm64 arch code operating on ranges it
both wholly owns and does not concurrently write.
The latter category consists of kernel page table walkers operating on
ranges that are wholly owned (but which need exclusion against concurrent
writers).
The lock used for exclusion is the mmap lock, and for kernel ranges this
is the mmap lock on init_mm.
ptdump is a special case being both the only user of
walk_page_range_debug(), and the only case in which it walks ranges it
does not own.
This presents a problem, as page tables may be freed under ptdump. And
indeed there is a use-after-free bug in the kernel as a result, which this
series addresses.
vmap promotes page tables to huge leaf entries where possible, freeing the
lower page table when it does. It does this with no meaningful locks held
against concurrent ptdump walks.
As a result, use-after-free can currently occur. This series addresses
the issue by having the vmap huge promotion logic acquire the mmap read
lock while both setting the huge page table entry and freeing the prior
leaf page table.
The ptdump code already acquires the mmap write lock, so by doing so we
ensure that the ptdump walker only ever observes either the huge page
table entry or the existing page table entry, and nothing is freed
underneath it.
A mitigation for this issue was already applied for arm64 in commit
fa93b45fd397 ("arm64: Enable vmalloc-huge with ptdump"), which this series
has to deal with carefully.
This mitigation resolves the issue by acquiring the mmap read lock on
init_mm on vmap page table free if a ptdump is in progress.
However the fix in this series would cause a deadlock if we were to simply
apply it for arm64 without also reverting the change.
This is because vmap may acquire the read lock before ptdump attempts to
acquire the write lock, which then gets queued, and rwsem starvation rules
mean that the (unacknowledged) nested mmap read lock in the arm64 code
would also block, meaning the original read lock is never released and
thus deadlock.
This series works around this by #ifndef CONFIG_ARM64'ing the mmap read
lock in vmap logic, then partially reverting commit fa93b45fd397 ("arm64:
Enable vmalloc-huge with ptdump"), keeping the enablement of huge vmap
support, and removing the ifdeffery with the partial revert patch.
There are related issues that are also addressed in this series:
* x86 page attribute logic, specifically Change Page Attributes (CPA),
implements a feature whereby huge ranges can be collapsed into huge leaf
entries. This can similarly cause a UAF when done in parallel with a
ptdump walk, so similarly acquire the init_mm mmap lock to avoid this.
* The CPA logic allows concurrent page table manipulation and CPA
collapse, meaning the former risks accessing a page table the latter
frees. Fix this by acquiring mmap write lock on init_mm across the
whole CPA collapse operation and read lock on the page table
manipulation.
* x86 and arm64 permit walks of non-kernel mm's (both allowing efi mm
walks, and in x86's case arbitrary mm's), so we ensure kernel mappings
remain stable by locking the init_mm as well as the mm being walked.
The ordering of patches is established for both strict dependencies (the
arm64 partial revert in particular has to be done after the vmap changes)
and logical ones (the non-kernel mm fix only makes sense once the vmap/CPA
fixes are in place).
This patch (of 3):
Currently there is a nasty ra
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb: Fix UAF at delayed release of MIDI2 EPs
The recent fix for UAF in ump_to_endpoint() caused another UAF because
it tries to dereference the UMP endpoint object, but this might be
executed at a delayed context where the endpoint has been already
released.
Add private_free to clear the associated data for avoiding the further
dereference for delayed releases. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: fix use-after-free of cached ASCONF chunk
addip_last_asconf caches the outstanding outbound ASCONF chunk. The normal
ASCONF-ACK completion path releases the chunk and clears the pointer.
However, sctp_asconf_queue_teardown() releases the cached chunk without
clearing addip_last_asconf. During peer restart handling,
sctp_sf_do_dupcook_a() queues SCTP_CMD_PURGE_ASCONF_QUEUE, which invokes
sctp_asconf_queue_teardown() while the association remains alive and leaves
the pointer dangling.
A delayed authenticated ASCONF-ACK can then reach sctp_sf_do_asconf_ack(),
which accesses the stale chunk and passes it to sctp_process_asconf_ack(),
causing a use-after-free and a second release.
Clearing the pointer exposes a race with T4 expiry. Peer restart handling
queues the timer stop before the purge, but SCTP_CMD_TIMER_STOP uses
timer_delete(), which does not wait for a callback already running on
another CPU. Such a callback can reach sctp_sf_t4_timer_expire() after
the purge and dereference NULL.
Clear addip_last_asconf after releasing the cached chunk, and make
sctp_sf_t4_timer_expire() consume a stale T4 expiry if no outstanding
ASCONF remains. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix sk_redir use-after-free in send verdict
sk_psock_msg_verdict() takes a socket reference for psock->sk_redir.
tcp_bpf_send_verdict() copies that pointer while holding the source socket
lock, but does not take a reference for the local copy before dropping the
lock around tcp_bpf_sendmsg_redir().
When apply_bytes keeps the cached verdict active, another sendmsg() on the
same source socket can consume the remaining bytes and release the cached
reference while the first thread still holds only the raw local pointer:
CPU 0 CPU 1
sk_redir = psock->sk_redir
apply_bytes remains nonzero
release_sock(sk)
lock_sock(sk)
apply_bytes reaches zero
psock->sk_redir = NULL
release_sock(sk)
tcp_bpf_sendmsg_redir(sk_redir)
sock_put(sk_redir)
tcp_bpf_sendmsg_redir(sk_redir)
The final sock_put() can free sk_redir before CPU 0 dereferences it.
KASAN reported:
BUG: KASAN: slab-use-after-free in tcp_bpf_sendmsg_redir+0xf39/0x1020
Read of size 8 at addr ffff888108537090 by task poc/87
Call Trace:
tcp_bpf_sendmsg_redir+0xf39/0x1020
tcp_bpf_sendmsg+0x977/0x1a50
__sys_sendto+0x32c/0x3a0
__x64_sys_sendto+0xdb/0x1b0
Allocated by task 85:
sk_prot_alloc+0x56/0x210
sk_clone+0x6f/0x14b0
inet_csk_clone_lock+0x24/0x740
tcp_create_openreq_child+0x25/0x2710
tcp_v4_syn_recv_sock+0x10a/0xe00
Freed by task 0:
__kasan_slab_free+0x43/0x70
slab_free_after_rcu_debug+0xa6/0x1e0
rcu_core+0x50a/0x1850
Last potentially related work creation:
__sk_destruct+0x3da/0x540
sk_psock_destroy+0x81e/0xab0
process_one_work+0x63a/0x1070
Take a temporary socket reference while the source socket lock still
protects psock->sk_redir, and drop it after tcp_bpf_sendmsg_redir()
returns. This keeps each unlocked use independent of cached-verdict
ownership. |
| In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: avoid refilling the RX queue after teardown
Commit b917507e5ad9 ("vsock/virtio: stop workers during the .remove()")
made the RX worker jump to its common exit when rx_run is clear. That
exit still refills the RX queue when the buffer count is low, so work
queued across virtio_vsock_vqs_del() can add buffers after the virtqueues
have been deleted.
BUG: KASAN: slab-use-after-free in virtqueue_add_sgs
Read of size 4 by task kworker/0:1
Workqueue: virtio_vsock virtio_transport_rx_work
Call Trace:
virtqueue_add_sgs (drivers/virtio/virtio_ring.c:2796)
virtio_vsock_rx_fill (net/vmw_vsock/virtio_transport.c:332)
virtio_transport_rx_work (net/vmw_vsock/virtio_transport.c:701)
process_one_work (kernel/workqueue.c:3314)
worker_thread (kernel/workqueue.c:3478)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
...
Freed by task 141:
kfree (mm/slub.c:6566)
vp_del_vq (drivers/virtio/virtio_pci_common.c:259)
vp_del_vqs (drivers/virtio/virtio_pci_common.c:285)
virtio_vsock_freeze (net/vmw_vsock/virtio_transport.c:912)
virtio_device_freeze (drivers/virtio/virtio.c:658)
virtio_pci_freeze (drivers/virtio/virtio_pci_common.c:601)
pci_pm_freeze (drivers/pci/pci-driver.c:1098)
device_suspend (drivers/base/power/main.c:1968)
Kernel panic - not syncing: KASAN: panic_on_warn set ...
Jump to a no-refill exit when rx_run is clear, leaving the normal exit
to replenish a running queue. |
| In the Linux kernel, the following vulnerability has been resolved:
net/dibs: Correct freeing of dmb_clientid_arr
A dibs device interrupt handler can be active after dibs_dev_del() and
may still access dmb_clientid_arr. (UAF)
In case of a failure in dibs_dev_add() being called by dibs_lo_dev_probe()
dmb_clientid_arr is freed twice (double free).
Free dmb_clientid_arr in dibs_dev_release() after last reference is gone.
Note that allocating in dibs_dev_add() instead of dibs_dev_alloc() is ok
for now, because no dmbs can be registered before dibs_dev_add(). |
| In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Prevent subbuf order change when resizing is disabled
Because ring_buffer_subbuf_order_set() frees buffer pages, we can't
allow it when resizing is disabled. A non-consuming reader is at risk of
use-after-free (rb_advance_iter()).
Return -EBUSY on resize_disabled, matching ring_buffer_resize()
behaviour. |
| In the Linux kernel, the following vulnerability has been resolved:
ovpn: skip rehash for peers already removed from by_id
ovpn_nl_peer_set_doit() resolves the target peer via
ovpn_peer_get_by_id() before taking ovpn->lock. In the window between
the lookup (which only takes a refcount) and the subsequent
spin_lock_bh(&ovpn->lock), a concurrent OVPN_CMD_PEER_DEL, keepalive
expiry, or socket teardown can take ovpn->lock first, run
ovpn_peer_remove() to unhash the peer from all four tables (by_id,
by_vpn_addr4/6, by_transp_addr) and release the lock. set_doit then
acquires ovpn->lock and calls ovpn_peer_hash_vpn_ip(), which
re-inserts the now-removed peer back into the rehashing tables.
The same race affects the float path: ovpn_peer_endpoints_update()
holds only a refcount and acquires ovpn->lock very late (after async
AEAD decrypt and a netlink notification), then rehashes the peer
in the by_transp_addr table.
The resurrected peer becomes reachable again from the RX lookup
(ovpn_peer_get_by_transp_addr) and the TX VPN-IP lookup, even though
userspace believes it is gone. Once the data-path refcount drops the
peer is freed via call_rcu while the hash entries embedded in it
remain linked, opening a UAF window.
Bail out of the rehash when hash_entry_id is unhashed, mirroring
the sentinel already used by ovpn_peer_remove() to detect the
already-removed state. The check is safe under ovpn->lock, which
serializes every mutation of hash_entry_id, and is a no-op for the
add path because ovpn_peer_add_mp() inserts hash_entry_id before
calling ovpn_peer_hash_vpn_ip(). |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: do not arm the ageing timer on a device that is down
vxlan_changelink() arms vxlan->age_timer whenever the requested ageing
interval differs from the configured one:
if (conf.age_interval != vxlan->cfg.age_interval)
mod_timer(&vxlan->age_timer, jiffies);
There is no netif_running() test, so the timer is armed even on a device
that was never brought up. The only synchronous cancel in the driver is
the timer_delete_sync() in vxlan_stop(), which is .ndo_stop.
netif_close_many() drops devices without IFF_UP before
__dev_close_many() runs, so that cancel is skipped for such a device.
vxlan_setup() sets dev->needs_free_netdev = true and age_timer is a
member of struct vxlan_dev, so free_netdev() releases the allocation the
timer lives in while it is still queued on a timer_base.
expire_timers() unlinks the entry before it loads timer->function, so
the timer core writes through the freed object's list pointers:
BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654
Write of size 8 at addr ffff00001adace68 by task true/192
__asan_store8+0x84/0xac
__run_timers+0x208/0x654
run_timer_softirq+0x154/0x18c
Allocated by task 189:
alloc_netdev_mqs+0x64/0x720
rtnl_create_link+0x4ac/0x520
rtnl_newlink+0x758/0xd00
Freed by task 191:
netdev_release+0x40/0x58
netdev_run_todo+0x4a4/0x8c0
rtnl_dellink+0x200/0x4e8
The rtnl operations involved are netns-scoped, so an unprivileged user
can perform them in a new user and network namespace.
Arming the timer on a down device never had an effect: vxlan_cleanup()
returns early on !netif_running(), and vxlan_open() arms the timer for
any non-zero interval once the device is brought up. Add the missing
test.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
mac802154: fix netdev use-after-free in beacon worker
mac802154_beacon_worker() reads local->beacon_req under RCU and derives
the sub-interface from the request, but then drops the RCU read lock and
continues to use both sdata and the embedded wpan_dev.
mac802154_stop_beacons_locked() cancels only pending beacon work, clears
local->beacon_req and frees the request. A beacon worker that is already
running can therefore continue after interface teardown and dereference
the freed netdev private area.
The scan worker already pins the netdev before leaving RCU. Apply the
same lifetime rule to the beacon worker: take a netdev reference while
the request is still protected by RCU, and release it on all paths that
continue after the reference is acquired. |
| In the Linux kernel, the following vulnerability has been resolved:
eventfs: Fix use-after-free in eventfs_remove_rec()
eventfs_remove_rec() recursively removes the child at the current loop
position. After the recursive call returns, list_for_each_entry() advances
by reading list.next from the removed child.
If free_ei() drops the final reference, release_ei() reuses the list/rcu
union to queue an SRCU callback. The child may be freed before that read.
The eventfs_mutex serializes list updates, but it does not keep the removed
child alive or prevent the SRCU callback from running.
Use list_for_each_entry_safe() to save the next sibling before recursively
removing the current child. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: keep chunk->transport in step with the list it is queued on
__sctp_outq_flush_rtx() moves a gap-acked chunk onto another transport's
transmitted list without updating chunk->transport:
if (chunk->tsn_gap_acked) {
list_move_tail(&chunk->transmitted_list,
&transport->transmitted);
continue;
}
The chunk then sits on a live transport's list while chunk->transport still
names a different one. If that transport is removed - sctp_assoc_rm_peer()
from an ASCONF Delete-IP - sctp_transport_free() RCU-frees it and the chunk
is left with a dangling pointer. sctp_assoc_rm_peer() scrubs
peer->transmitted and asoc->outqueue.out_chunk_list, but the chunk is on
neither.
The pointer is not followed while tsn_gap_acked is set. A SACK that
reneges on the TSN clears the flag, and the next SACK reaches
tchunk->transport->flight_size -= sctp_data_size(tchunk);
inside the freed transport. KASAN reports a slab-use-after-free read in
sctp_check_transmitted(), freed from sctp_assoc_rm_peer(). Both the
removal and the SACKs come from the association peer.
Set chunk->transport at the move. The ordinary resend path needs nothing:
it reaches its list_move_tail() only after sctp_packet_append_chunk()
returned SCTP_XMIT_OK, and __sctp_packet_append_chunk() has rebound the
chunk by then.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_route: fix fastmap use-after-free on filter
The route4 classifier maintains a 16-slot fastmap cache that stores raw
struct route4_filter pointers indexed by (id, iif). The reader
(route4_classify) populates this cache via route4_set_fastmap() for every
classified packet that hits a filter. The writer (route4_delete,
route4_change) clears the cache via route4_reset_fastmap() before
RCU-deferred kfree of the filter.
This creates a UAF race:
1. Reader walks the RCU-protected bucket chain, finds filter f
2. Writer unlinks f, calls route4_reset_fastmap(), then tcf_queue_work()
3. Reader calls route4_set_fastmap() and writes f into the cache
*after* the writer's reset, caching a pointer about to be freed
4. After the RCU grace period, kfree(f) executes
5. Next classified packet on the same (id, iif) tuple hits the stale
fastmap entry and reads f->res from freed memory
Reproduced with an mdelay(100) accelerator in route4_set_fastmap() and a
concurrent add/delete stress test (provided by both zdi and Santosh).
Both triggered KASAN slab-use-after-free reports in the route4 fastmap
paths.
Fix:
Introduce a per-filter boolean dying flag to suppress stale fastmap
republishing by in-flight readers. |
