| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: gw: acquire ethernet header only after skb realloc
The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free. |
| In the Linux kernel, the following vulnerability has been resolved:
block: stop the timeout timer when releasing a never added disk
disk_release() undoes blk_mq_init_allocated_queue() for a disk whose
probe failed before add_disk(), but it only calls blk_mq_exit_queue().
Nothing there stops q->timeout, and that timer rolls forward: it stays
pending until it next expires, not until the last request completes.
So if the driver issued any I/O before adding the disk, the
request_queue is freed while still linked into a timer wheel bucket.
Commit 6f8191fdf41d ("block: simplify disk shutdown") dropped the
blk_cleanup_queue() call that used to stop it. __del_gendisk() and
blk_mq_destroy_queue() still do; only the probe failure path lost it.
nvme gets there because nvme_update_ns_info() submits Report Zones or
FDP io-mgmt-recv on ns->queue before the disk is added, so a later
failure - a concurrent reset setting NVME_CTRL_FROZEN, or
device_add_disk() failing - lands in put_disk() with the timer armed:
BUG: KASAN: slab-use-after-free in detach_if_pending+0x30c/0x340
Write of size 8 at addr ffff888004d71310 by task kworker/u8:2/37
__timer_delete_sync+0x156/0x240 kernel/time/timer.c:1621
blk_sync_queue+0x22/0x40 block/blk-core.c:222
nvme_sync_queues+0x100/0x150 drivers/nvme/host/core.c:5362
nvme_reset_work+0x138/0x930 drivers/nvme/host/pci.c:3264
Allocated by task 34:
__blk_mq_alloc_disk+0x33/0x100 block/blk-mq.c:4462
nvme_alloc_ns+0x290/0x3870 drivers/nvme/host/core.c:4146
Freed by task 0:
blk_free_queue_rcu+0x3a/0x50 block/blk-core.c:254
rcu_core+0xc10/0x1730 kernel/rcu/tree.c:2857
The queue being synced there is ctrl->admin_q, only a victim sharing a
timer wheel bucket with the freed queue's dangling entry; other runs
tripped in enqueue_timer(), __run_timers() or blk_mq_timeout_work().
Failing nvme_alloc_ns() with a debug patch makes it deterministic: one
leaked timer trips KASAN within seconds, while 1987 patched releases
produced no splat.
Stop the timer and the queue work items before blk_mq_exit_queue(), like
blk_mq_destroy_queue() does.
Found by FuzzNvme. |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: clear fb_info->mode before deleting a videomode
fb_set_var() can delete a mode from info->modelist when userspace
passes FB_ACTIVATE_INV_MODE through FBIOPUT_VSCREENINFO. The code
checks that the mode being deleted is not the current info->var and
that fbcon is not using it, but it does not check fb_info->mode.
fb_info->mode may still point into the modelist entry being deleted.
If the entry is freed, later mode sysfs reads through show_mode() can
dereference a stale pointer.
Clear fb_info->mode before calling fb_delete_videomode() when it
matches the mode being removed. |
| In the Linux kernel, the following vulnerability has been resolved:
perf: Reject exited events as group leaders
perf_event_remove_on_exec() sets remove-on-exec events to the EXIT state
and detaches their group relationships. The event's file descriptor can
remain open, however, and perf_event_open() currently accepts that event
as a group leader because its early validation rejects only REVOKED and
DEAD events.
A new sibling can consequently be linked to the detached leader. When
the leader is closed, perf_group_detach() observes that its
PERF_ATTACH_GROUP bit is already clear and skips the new sibling. The
sibling then retains a group_leader pointer to the freed event.
Reject group leaders in the EXIT state. Perform the check while holding
the shared context mutex so that an exec in the target task cannot detach
the leader between validation and group attachment.
[peterz: make the earlier test fully consistent] |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: publish GC-visible tuple last
nf_flow_table_iterate() only treats original-direction tuple nodes as
owning entries. Publishing the original node first lets GC observe and
free a flow while flow_offload_add() is still inserting the reply node.
Publish the reply node first and the original node last so GC never
sees a partially installed flow.
KASAN can trigger slab-use-after-free read and write reports in the
flowtable/rhashtable path (rht_deferred_worker, jhash, flow_offload_del,
flow_offload_lookup, etc.). |
| In the Linux kernel, the following vulnerability has been resolved:
udp: fix potential use-after-free in tunnel segmentation
__skb_udp_tunnel_segment() gets the UDP header before ensuring the
tunnel header is in the skb head. If the pull reallocates skb->head,
the saved UDP header pointer is no longer valid.
Get the UDP header after the pull to avoid a potential use-after-free. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: clear control chunk transport if it is being removed
sctp_make_heartbeat_ack() caches the destination transport in
chunk->transport without taking a reference. When src_out_of_asoc_ok is
enabled, the HEARTBEAT ACK may remain queued on control_chunk_list instead
of being transmitted immediately.
If the peer transport is removed while the chunk is still queued,
sctp_assoc_rm_peer() drops the transport and schedules it for RCU freeing,
but only clears cached transport pointers in out_chunk_list. The queued
control chunk therefore retains a dangling transport pointer.
Once an ASCONF_ACK clears the suppression and the queued control chunk is
transmitted, SCTP dereferences the stale transport pointer, leading to a
use-after-free.
Fix this by also clearing chunk->transport for queued control chunks in
control_chunk_list when removing the transport. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebt_nflog: pin the NFLOG backend
nf_log_unregister() runs after the per-net teardown so its final RCU
grace period also drains readers that obtained the logger from a per-net
binding. However, ebt_nflog passes an explicit ULOG log type to
nf_log_packet() without holding a reference on the selected logger module,
unlike the xt_NFLOG and nft_log frontends.
An ebtables nflog rule can therefore remain callable while nfnetlink_log
is unloaded. The resulting interleaving is:
CPU 0 CPU 1
nfnetlink_log_fini()
unregister_pernet_subsys()
kfree(nfnl_log_pernet(net))
ebt_nflog_tg()
nf_log_packet()
nfulnl_log_packet()
instance_lookup_get_rcu()
The global ULOG logger is still registered at this point, so CPU 1
dereferences the per-net state after CPU 0 has freed it. KASAN reported:
BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu
Read of size 8 at addr ff110001052e6210 by task poc/92
Call Trace:
instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log]
nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log]
nf_log_packet+0x204/0x300
ebt_nflog_tg+0x351/0x550
ebt_do_table+0xedf/0x22b0
Allocated by task 90:
__kmalloc_noprof+0x186/0x470
ops_init+0x6d/0x420
register_pernet_operations+0x2f6/0x670
register_pernet_subsys+0x23/0x40
Freed by task 93:
kfree+0x131/0x3c0
ops_undo_list+0x3e3/0x700
unregister_pernet_operations+0x232/0x490
unregister_pernet_subsys+0x1c/0x30
nfnetlink_log_fini+0x34/0x450 [nfnetlink_log]
Acquire the ULOG logger module reference when an ebt_nflog rule is
validated and release it when the rule is destroyed. Request the NFLOG
backend for legacy callers when needed, matching xt_NFLOG. This prevents
module teardown until all ebt_nflog rules have stopped using the logger. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix group leader use-after-free after sibling detach
perf_group_detach() handles leader and sibling detach differently. When the
group leader is detached, all siblings are promoted to singleton events and
their group_leader pointer is reset to themselves. When a sibling is
detached, it is removed from the leader's sibling_list, but its
group_leader pointer is left pointing at the old leader.
That is harmless when the sibling is being closed and freed immediately, as
in the DETACH_DEAD path. It is not safe when the sibling is detached but
kept alive, such as during CPU hotplug with DETACH_GROUP. In that case the
sibling is removed from the context, while its file descriptor can still
keep it alive.
A typical failing sequence is:
- A group contains leader L and sibling S.
- CPU hot-unplug detaches S with DETACH_GROUP, removing it from
L->sibling_list but leaving S->group_leader == L.
- L is later closed and freed.
- A PERF_IOC_FLAG_GROUP ioctl on S follows S->group_leader and
dereferences the freed leader.
This was reproduced by running the perf event fuzzer, CPU hotplug, and a
stress workload concurrently:
Unable to handle kernel paging request at virtual address 006b6b6b6b6b6cdb
CPU: 2 PID: 12489 Comm: perf_fuzzer 6.18.7 PREEMPT
pc : perf_ioctl+0x34c/0xc68
x20: ffffff89a3fa2c70 x8 : 6b6b6b6b6b6b6b6b
Code: 943c4a0e 340047a0 f9404a94 f9411e88 (f940b908)
Call trace:
perf_ioctl+0x34c/0xc68 (P)
__arm64_sys_ioctl+0xa0/0xf4
invoke_syscall+0x58/0xe4
el0_svc_common+0xa8/0xdc
do_el0_svc+0x1c/0x28
el0_svc+0x40/0xc0
el0t_64_sync_handler+0x68/0xdc
el0t_64_sync+0x1c4/0x1c8
The fault happened in perf_ioctl(), where perf_event_for_each() follows
the stale group_leader pointer and perf_event_for_each_child() then
dereferences the freed leader's context.
Fix the use-after-free by promoting the detached sibling to a singleton.
Also fix __event_disable() cgroup accounting and event state change. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: read le->link under the node lock in tipc_node_link_down()
tipc_node_link_down() caches the link pointer before taking n->lock:
struct tipc_link *l = le->link; /* unlocked */
if (!l)
return;
tipc_node_write_lock(n);
if (!tipc_link_is_establishing(l)) { /* deref l */
...
tipc_link_reset(l); /* write into l */
if (delete) {
kfree(l);
le->link = NULL;
The delete=true caller frees that very object under n->lock, so the lock
does not protect the cached pointer against it:
- CPU A, delete=false: tipc_rcv() on TIPC_LINK_DOWN_EVT, or the link
supervision timer via tipc_node_timeout(), reads l unlocked and then
dereferences it under n->lock;
- CPU B, delete=true: netlink TIPC_NL_BEARER_DISABLE -> bearer_disable()
-> tipc_node_delete_links() -> tipc_node_link_down(n, bearer_id, true)
-> kfree(l).
The link is freed with plain kfree(), not kfree_rcu(), and for UDP bearers
disable_media() only schedules the asynchronous cleanup_bearer() work, so
its synchronize_net() runs after the links are already gone. An in-flight
CPU A that has read l therefore dereferences freed memory once B frees it:
a use-after-free read in tipc_link_is_establishing(), and a use-after-free
write via tipc_link_reset() on the establishing branch.
The following trace was captured on 7.2.0-rc5-00284-gaf39eb111ce6:
BUG: KASAN: slab-use-after-free in tipc_link_is_establishing (net/tipc/link.c:285)
Read of size 4 at addr ffff88802e2aa068 by task swapper/2/0
tipc_link_is_establishing (net/tipc/link.c:285)
tipc_node_link_down (net/tipc/node.c:1076)
tipc_node_timeout (net/tipc/node.c:843)
Allocated by task 9549:
tipc_link_create (net/tipc/link.c:490)
tipc_node_check_dest (net/tipc/node.c:1279)
tipc_disc_rcv (net/tipc/discover.c:252)
tipc_udp_recv (net/tipc/udp_media.c:389)
Freed by task 9549:
tipc_node_link_down (net/tipc/node.c:1084)
tipc_node_delete_links (net/tipc/node.c:1320)
bearer_disable (net/tipc/bearer.c:414)
__tipc_nl_bearer_disable (net/tipc/bearer.c:992)
Move the le->link read inside tipc_node_write_lock(), so it is serialised
against the kfree() in the delete path. A racing teardown now either has
not run yet, and we see a valid link, or has already run, and we see NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: Fix use-after-free in cifs_try_adding_channels()
cifs_try_adding_channels() takes a temporary reference to an interface
before dropping iface_lock. If cifs_ses_add_channel() fails, it drops
that reference and then increments iface->weight_fulfilled.
A concurrent interface list refresh can remove the list reference while
channel creation is in progress. In that case, the failure-path
kref_put() releases the last reference and frees iface. Updating
weight_fulfilled afterward then accesses freed memory.
Increment weight_fulfilled before dropping the temporary reference,
keeping iface alive for the final access. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "thermal/drivers/hwmon: Cleanup coding style a bit"
Revert commit 030a48b0f6ce ("thermal/drivers/hwmon: Cleanup coding style
a bit") that introduced a use-after-free into the error path of
thermal_add_hwmon_sysfs() by removing a valid check from it. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: clear new_transport when removing a peer
sctp_process_asconf_param() stores a newly added peer transport in
asoc->new_transport. After all parameters in the ASCONF chunk have been
processed, sctp_sf_do_asconf() uses this pointer to send a HEARTBEAT to the
new transport.
An authenticated ASCONF from a remote SCTP peer can add a transport and
remove it again with a wildcard DEL-IP parameter in the same chunk. The
wildcard deletion preserves the transport on which the ASCONF arrived, but
removes the newly added transport through
sctp_assoc_del_nonprimary_peers(). The removal does not clear
asoc->new_transport, leaving it pointing to the removed transport.
sctp_sf_do_asconf() then creates a HEARTBEAT whose chunk->transport points
to the removed transport without holding a transport reference. During
local address replacement, src_out_of_asoc_ok keeps this HEARTBEAT on
control_chunk_list. After the transport is freed by RCU, a successful
ASCONF_ACK for the replacement address releases the queued HEARTBEAT and
sctp_outq_select_transport() reads the freed transport's state.
The issue was found during a static audit of SCTP objects. With an
authenticated peer, the reproducer triggered the same KASAN report in 2
of 2 unpatched runs on a KASAN-enabled netdev/main kernel:
BUG: KASAN: slab-use-after-free in sctp_outq_select_transport
Read of size 4 at addr ffff88800b9bd95c by task python3/197
Call Trace:
sctp_outq_select_transport+0x549/0x8b0 [sctp]
sctp_outq_flush+0x306/0x2c60 [sctp]
sctp_transport_immediate_rtx+0xaf/0x260 [sctp]
sctp_process_asconf_ack+0xa48/0xf70 [sctp]
Allocated by task 197:
sctp_transport_new+0x68/0x650 [sctp]
sctp_assoc_add_peer+0x258/0x12a0 [sctp]
sctp_process_asconf+0x5e9/0x1090 [sctp]
Last potentially related work creation:
__call_rcu_common.constprop.0+0x77/0xb70
sctp_assoc_del_nonprimary_peers+0x7c/0xd0 [sctp]
sctp_process_asconf+0xd9c/0x1090 [sctp]
The first invalid access was a four-byte read of transport->state at
net/sctp/outqueue.c:833. The same reproducer completed the full
authenticated ASCONF and local-address replacement sequence with this
change without a KASAN report or oops.
Clear new_transport when its peer is removed, before it can be used to
create the HEARTBEAT. |
| In the Linux kernel, the following vulnerability has been resolved:
vhost: reset the vring metadata cache on vring reconfiguration
vq->meta_iotlb[] caches the vhost_iotlb_map that backs each vring
metadata region, and iotlb_access_ok() returns early on a cache hit,
taking the hit as proof that the region has already been validated:
if (vhost_vq_meta_fetch(vq, addr, len, type))
return true;
The cache is reset on VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE, on
device IOTLB (re)initialisation and on vq reset, but not when
VHOST_SET_VRING_ADDR replaces vq->desc, vq->avail and vq->used, nor when
VHOST_SET_VRING_NUM changes the region sizes.
With a device IOTLB attached both ioctls are accepted while the vq is
live, and neither validates the addresses at ioctl time: vq_access_ok()
and vq_log_used_access_ok() return true early because the addresses are
GIOVAs, deferring validation to prefetch time. Once the cache has been
populated that deferred validation no longer runs -- vq_meta_prefetch()
hits the stale entry and returns true -- and vhost_vq_meta_fetch() keeps
translating through the old mapping as
map->addr + addr - map->start
for an address the mapping no longer covers. vhost_copy_to_user() and
vhost_copy_from_user() consume the result with __copy_to_user() and
__copy_from_user(), which do not check it either, so a subsequent used
ring update or descriptor fetch accesses memory outside the region the
IOTLB actually maps.
Reset the metadata cache whenever the vring is reconfigured, so the new
addresses are pushed back through iotlb_access_ok()'s slow path. |
| In the Linux kernel, the following vulnerability has been resolved:
forcedeth: fix UAF of txrx_stats in nv_remove
nv_remove() frees the per-CPU txrx_stats before unregister_netdev().
Until unregister completes, ndo_get_stats64, the NAPI/xmit data path,
and nv_close()/drain may still access txrx_stats, leading to a
use-after-free.
Free the stats only after unregister_netdev(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: avoid deadlocks in iso_sock_timeout
iso_sock_timeout() takes lock_sock, so sync disabling the timer while
holding that lock may deadlock.
iso_sock_timeout() may also run concurrently with iso_conn_del(), which
leads to UAF
[Task 1] [Task hdev->workqueue]
iso_sock_timeout iso_conn_del
iso_conn_hold_unless_zero iso_chan_del
`------------> iso_conn_put
caller frees hcon
iso_conn_put
iso_conn_free
conn->hcon->iso_data = NULL; /* UAF */
Fix the deadlock by removing the disable from the lock_sock sections.
Move the timer from iso_conn to iso_pinfo to decouple it from iso_conn
which may need to be freed in lock_sock section. Convert some of the
clear_timer to disable_timer. |
| In the Linux kernel, the following vulnerability has been resolved:
audit: fix potential use-after-free in audit_del_rule()
`audit_del_rule()` destroys `e->rule.exe` via `audit_remove_mark_rule()`
before unlinking the rule from RCU-visible filter lists and waiting for a
grace period. Concurrent readers in `audit_filter()` and
`audit_filter_rules()` still dereference `e->rule.exe`, while the fsnotify
mark can be freed on an independent lifetime path. This creates a
use-after-free window during rule deletion.
Fix this by unlinking the rule from the RCU-visible lists and invoking
`synchronize_rcu()` before calling `audit_remove_mark_rule()` (and other
rule removal helpers). This ensures that all existing RCU readers have
exited the critical section before any underlying resources are destroyed. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: mgmt: fix UAF in pair command cancellation
The pairing completion and authentication failure callbacks look up the
pending MGMT_OP_PAIR_DEVICE command by walking hdev->mgmt_pending. The
lookup returned a command that was still linked on the shared pending list,
without keeping mgmt_pending_lock held for the later dereference and
removal.
A concurrent MGMT_OP_CANCEL_PAIR_DEVICE request can remove and free the
same pending command before the callback uses it. The reverse race is also
possible when cancel_pair_device() gets a command from pending_find() and a
callback removes it before the cancel path dereferences it. This can lead
to a use-after-free and a second list_del().
Make the pairing lookup helpers transfer ownership of the pending command
by removing it from hdev->mgmt_pending while holding mgmt_pending_lock.
The callbacks and cancel path then complete the command and free it
directly, so racing paths cannot find or free the same command again. Take
a temporary hci_conn reference in cancel_pair_device() because the command
completion drops the reference stored in the pending command. |
| In the Linux kernel, the following vulnerability has been resolved:
fou: Fix use-after-free in fou_create()
fou_create() publishes struct fou through sk_user_data before adding the
new FOU port to the per-netns list. If fou_add_to_port_list() fails,
the error path frees fou while it is still reachable through
sk_user_data. A concurrent receive can then dereference the freed
object in fou_from_sock().
This ordering issue was previously noted in the linked discussion.
The failure is reachable when local port 0 is requested. Each socket
binds to a different ephemeral port, but fou_cfg_cmp() compares the
requested port 0 and reports -EALREADY once an entry already exists.
Release the tunnel socket before freeing fou so sk_user_data is cleared
first, and defer reclamation with kfree_rcu() to protect concurrent RCU
readers. This matches the lifetime handling in fou_release(). |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix socket use-after-free during link group termination
__smc_lgr_terminate() drops conns_lock after finding a connection in
lgr->conns_all, but before taking a reference on its socket. The connection
is embedded in the socket, and its registration reference protects it only
while the connection remains in the tree.
A concurrent close can unregister the connection and drop that reference,
freeing the socket before the termination worker reaches sock_hold().
The race is reachable when close overlaps link group termination.
Local stress testing reproduced the use-after-free and KASAN reported:
BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]
Write of size 4 by task kworker/3:3
Workqueue: events smc_lgr_terminate_work [smc]
__smc_lgr_terminate.part.0 [smc]
The socket was allocated by smc_create(), freed through
slab_free_after_rcu_debug(), and was followed by:
refcount_t: addition on 0; use-after-free.
__smc_lgr_terminate.part.0 [smc]
Take the socket reference while conns_lock still protects the tree entry.
The unregister path then cannot drop the last reference until termination
has finished using the socket. |
