| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: always drain cache_cleaner before destroying a cache_detail
sunrpc_destroy_cache_detail() only cancels the global cache_cleaner
delayed_work when cache_list is empty. During per-netns teardown
cache_list is never empty because init_net's caches remain registered,
so the cancel never fires. After unlink, the caller proceeds to
cache_destroy_net() which kfrees the cache_detail while cache_clean()
may still hold a dangling pointer to it. The result is a
use-after-free: cache_dequeue() takes cd->queue_lock on freed memory,
and cache_put() dereferences cd->cache_put as a function pointer from
freed slab.
Drop the list_empty guard so that cancel_delayed_work_sync() always
runs, ensuring any in-flight cache_clean() completes before the
cache_detail is freed. Re-arm the cleaner afterwards if other caches
are still registered. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/cxgb4: Cancel reg_work before freeing device on remove
c4iw_uld_state_change() queues reg_work to register the RDMA device.
c4iw_remove() can free ctx->dev while this work is pending or running,
leaving c4iw_register_device() accessing the freed device.
Cancel reg_work before removing the device. The registration work can
tear down ctx->dev when registration fails, so do not unregister or
deallocate it again in that case.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
openvswitch: Fix CT limit teardown use-after-free
Packet processing uses CT limit state under RCU, while netns teardown
frees that state under ovs_mutex. The CT limit pointer was neither removed
from readers nor protected by a grace period, allowing packet processing to
dereference the freed state.
An unprivileged user can trigger this bug from a user and network
namespace, causing a slab-use-after-free in ovs_ct_execute() when the
netns is torn down.
Publish the CT limit pointer through RCU, remove it before teardown, and
wait for readers before freeing its contents. Keep ovs_mutex around
individual CT limit updates, and use the RCU read-side lock while GET
traverses the RCU-protected limit lists.
Netns teardown detaches the RCU-protected CT limit state in the pernet
.pre_exit callback while holding ovs_mutex. The pernet core guarantees an
RCU grace period between the .pre_exit and .exit callbacks, so the .exit
callback completes the teardown without adding any extra synchronization.
The netlink command handlers do not need NULL checks because the userspace
netlink socket holds an active reference to its network namespace while a
request is processed. The per-netns exit path therefore cannot run
concurrently with SET, DEL, or GET for that socket's namespace. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: stop processing a packet once its association is deleted
sctp_endpoint_bh_rcv() looks the association up only when chunk->asoc is
NULL, and caches the result in chunk->asoc and chunk->transport without
taking a reference.
A packet that matches no association is handed to the endpoint, so a peer
can bundle COOKIE ECHO, SHUTDOWN and SHUTDOWN ACK in one packet. The
COOKIE ECHO creates the association, the SHUTDOWN chunk caches it, and
with the outqueue empty the SHUTDOWN ACK reaches sctp_sf_do_9_2_final(),
so the association and its transports are freed.
The endpoint loop has no counterpart to the asoc->base.dead check in
sctp_assoc_bh_rcv(). The next chunk writes to last_time_heard in the freed
transport and is then passed to sctp_do_sm() with the freed association.
The transport is freed through RCU, so this needs the packet to come off
the socket backlog, where the loop runs in task context.
The endpoint loop cannot do the same check: it holds no reference on the
association, so reading asoc->base.dead would itself be a use-after-free.
Mark the packet for discard in the command interpreter, just before it
deletes the association. That is also before sctp_inq_free() releases the
chunk on the association receive path.
sctp_sf_do_5_2_4_dupcook() issues SCTP_CMD_DELETE_TCB for the temporary
association, while the one the packet belongs to stays alive. A restarting
peer can bundle DATA behind its COOKIE ECHO, so compare against
chunk->asoc and leave that case alone. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: drop a chunk if its transport was removed
sctp_rcv() resolves the transport once per packet and leaves it in
chunk->transport. The lookup reference, or the one sctp_add_backlog() takes
if the socket is owned by userspace, keeps it around until the chunk has
been processed.
An authenticated ASCONF DEL-IP can remove it in the meantime.
sctp_assoc_rm_peer() takes the transport out of the association and calls
sctp_transport_free(), which tags it dead and drops the reference the
association held. There is a window on both paths: the packet can sit on
the socket backlog, and on the direct path the lookup completes before
bh_lock_sock().
The DATA chunk in that packet puts the removed transport back into
asoc->peer.last_data_from. Once the packet is done that reference goes
away and the transport is freed by RCU, so the next delayed SACK carries
the pointer into the SACK chunk and sctp_outq_select_transport() reads the
freed transport's state.
Drop the chunk in sctp_inq_push(), next to the existing rcvr->dead check.
Both paths reach it with the association's socket lock held. The peer
retransmits it. |
| In the Linux kernel, the following vulnerability has been resolved:
slip: fix use-after-free in sl_sync()
slip_devs[] stores bare net_device pointers and takes no reference on
them. sl_sync() and sl_alloc() walk that table from slip_open() under
rtnl_lock(), while an entry is dropped by sl_free_netdev(), which
sl_setup() installs as dev->priv_destructor.
priv_destructor is called from netdev_run_todo(), which deliberately
runs with the RTNL semaphore released so that it can sleep while waiting
for the device refcount to drop:
/* Snapshot list, allow later requests */
list_replace_init(&net_todo_list, &list);
__rtnl_unlock();
...
if (dev->priv_destructor)
dev->priv_destructor(dev); /* slip_devs[i] = NULL */
if (dev->needs_free_netdev)
free_netdev(dev);
...
/* Free network device */
kobject_put(&dev->dev.kobj);
So rtnl_lock() does not serialise slip_open() against the teardown at
all. sl_sync() can load slip_devs[i] while the entry is still published
and dereference it after netdev_run_todo() has run the destructor and
released the device:
CPU0 (slip_open) CPU1 (slip_close)
unregister_netdev()
rtnl_unlock()
netdev_run_todo()
__rtnl_unlock()
rtnl_lock()
sl_sync()
dev = slip_devs[i]
priv_destructor(dev)
slip_devs[i] = NULL
kobject_put(&dev->dev.kobj)
/* dev is freed */
sl = netdev_priv(dev)
if (sl->tty || sl->leased) /* use-after-free */
BUG: KASAN: use-after-free in sl_sync drivers/net/slip/slip.c:730 [inline]
BUG: KASAN: use-after-free in slip_open+0xef4/0x1210 drivers/net/slip/slip.c:806
Read of size 1 at addr ffff8880712dac71 by task syz-executor.2/6506
CPU: 2 PID: 6506 Comm: syz-executor.2 Not tainted 6.1.134-syzkaller-00260-g0c8fc3469765 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
sl_sync drivers/net/slip/slip.c:730 [inline]
slip_open+0xef4/0x1210 drivers/net/slip/slip.c:806
tty_ldisc_open+0xa2/0x120 drivers/tty/tty_ldisc.c:433
tty_set_ldisc+0x324/0x720 drivers/tty/tty_ldisc.c:564
tiocsetd drivers/tty/tty_io.c:2428 [inline]
tty_ioctl+0x5f0/0x1530 drivers/tty/tty_io.c:2712
Allocated by task 6502:
alloc_netdev_mqs+0x98/0xfe0 net/core/dev.c:10719
sl_alloc drivers/net/slip/slip.c:756 [inline]
slip_open+0x36d/0x1210 drivers/net/slip/slip.c:817
tty_ldisc_open+0xa2/0x120 drivers/tty/tty_ldisc.c:433
tty_set_ldisc+0x324/0x720 drivers/tty/tty_ldisc.c:564
Freed by task 6497:
device_release+0xa2/0x240 drivers/base/core.c:2507
kobject_put+0x179/0x280 lib/kobject.c:729
netdev_run_todo+0x6c8/0xef0 net/core/dev.c:10509
slip_close+0x166/0x1c0 drivers/net/slip/slip.c:906
tty_ldisc_close+0x113/0x1a0 drivers/tty/tty_ldisc.c:456
tty_ldisc_kill+0x94/0x160 drivers/tty/tty_ldisc.c:614
tty_ldisc_release+0xe3/0x2b0 drivers/tty/tty_ldisc.c:782
tty_release+0xbcc/0xe70 drivers/tty/tty_io.c:1860
Commit e58c19124189 ("slip: Fix use-after-free Read in slip_open") fixed
a different source of stale entries - a device left in slip_devs[] after
slip_open() freed it on the registration error path - and does not
address this race, which is why the report survives it.
Drop the entry from ndo_uninit instead. unregister_netdevice() calls
ndo_uninit under RTNL, before the device is queued to netdev_run_todo(),
so an entry that sl_sync() can still see while holding RTNL belongs to a
device that cannot be freed until RTNL is dropped. sl_free_netdev()
stays only for the slip_open() error path, where register_netdevice()
may have failed before ndo_init and ndo_uninit is then not called
either. Both running for the same device is harmless: the
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix flow mask use-after-free on flow deletion
The commit in the Fixes tag below made so flow->mask free is scheduled
via RCU right after it is removed from the flow table. The pointer
stays in the flow structure and it can be accessible while in the same
RCU critical section. This is done to avoid requiring ovs_mutex for
the ovs_flow_free().
However, while removing the flow during processing of CMD_DEL, we do
not take RCU read lock before the removal, and ovs_flow_cmd_fill_info()
uses the flow->mask pointer afterwards. The RCU read lock is taken,
but it's already late at that point. The comment on that line
acknowledges that the lock is cosmetic and doesn't serve a real purpose.
This leads to use-after-free if the RCU grace period passes between
removal and the filling. It is a short race window, but it is there
and can lead to a real crash in case memory allocation for the info
takes a bit longer:
BUG: KASAN: slab-use-after-free in __ovs_nla_put_key
net/openvswitch/flow_netlink.c:1996
BUG: KASAN: slab-use-after-free in ovs_nla_put_key+0x2463/0x2e30
net/openvswitch/flow_netlink.c:2250
Read of size 4 at addr ffff88801ee89970 by task ovs_flow_del_ec/9487
Call Trace:
<TASK>
__ovs_nla_put_key net/openvswitch/flow_netlink.c:1996
ovs_nla_put_key+0x2463/0x2e30 net/openvswitch/flow_netlink.c:2250
ovs_flow_cmd_fill_info+0x420/0x9c0 net/openvswitch/datapath.c:930
ovs_flow_cmd_del+0x53a/0x970 net/openvswitch/datapath.c:1467
...
netlink_rcv_skb+0x156/0x420 net/netlink/af_netlink.c:2556
</TASK>
Allocated by task 9487:
mask_alloc net/openvswitch/flow_table.c:967
flow_mask_insert net/openvswitch/flow_table.c:1012
ovs_flow_tbl_insert+0xea2/0x1a90 net/openvswitch/flow_table.c:1084
ovs_flow_cmd_new+0x7e3/0xd90 net/openvswitch/datapath.c:1086
...
netlink_rcv_skb+0x156/0x420 net/netlink/af_netlink.c:2556
Freed by task 9485:
rcu_free_sheaf+0x1e/0x100 mm/slub.c:5978
rcu_do_batch kernel/rcu/tree.c:2645
rcu_core+0x59c/0x10c0 kernel/rcu/tree.c:2897
handle_softirqs+0x1e4/0x9a0 kernel/softirq.c:622
...
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062
ovs_flow_tbl_remove() must be called after the ovs_flow_cmd_fill_info()
to avoid this race. This also helps with cleaning up the forced cast
and the cosmetic RCU read lock. Before the commit in the Fixes tag the
order did not matter as long as the flow object itself was not freed.
A wider RCU critical section could be another option, but we have a
GFP_KERNEL allocation in the way.
Reported by Trend Micro's Zero Day Initiative as ZDI-CAN-32042. |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix use-after-free in smc_rx_pipe_buf_release()
smc_rx_splice() hands RMB pages to a pipe and takes a socket reference
per entry so the smc_sock stays alive until the reader finishes. The
connection does not: a concurrent close runs smc_conn_free(), which
releases the receive buffer back to the link group pool.
smc_rx_pipe_buf_release() tests sk_state before taking the socket lock.
The state can change between the test and the lock, and
smc_rx_update_cons() then dereferences conn->rmb_desc and walks
conn->lgr, which smc_conn_free() has already released. On the
is_reg_err path smcr_buf_unuse() frees the descriptor outright, so
this is a use-after-free.
Take the socket lock first and test conn->freed instead.
smc_conn_free() sets that flag before releasing anything, and every
caller holds the socket lock. The two paths exclude each other: either
the pipe release runs first with everything valid, or it sees the flag
and skips the update. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: bcd2000: clear the URB pointers on disconnect
bcd2000_free_usb_related_resources() frees both URBs and leaves the
pointers behind:
usb_kill_urb(bcd2k->midi_out_urb);
usb_kill_urb(bcd2k->midi_in_urb);
usb_free_urb(bcd2k->midi_out_urb);
usb_free_urb(bcd2k->midi_in_urb);
The rawmidi device outlives that call. A substream that is still open
when the device is unplugged reaches bcd2000_midi_send() from the
trigger path on close. That function writes to the freed URB and then
hands it to the USB core:
bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
...
ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
usb_kill_urb() does not stop a later submission either, so a submit that
races the disconnect can requeue the URB after it has been reaped.
midi_in_urb is exposed the same way: bcd2000_input_complete() resubmits
it from the completion handler.
KASAN on 7.2.0-rc5 (arm64):
BUG: KASAN: slab-use-after-free in bcd2000_midi_send [snd_bcd2000]
Write of size 4 at addr ffff00001827d388 by task bpoc/168
__asan_store4
bcd2000_midi_send [snd_bcd2000]
bcd2000_midi_output_trigger [snd_bcd2000]
snd_rawmidi_kernel_write1
close_substream.part.0
Freed by task 168:
usb_free_urb
bcd2000_disconnect [snd_bcd2000]
BUG: KASAN: slab-use-after-free in usb_submit_urb
Read of size 8 at addr ffff00001827d3b8 by task bpoc/168
Clear both pointers after freeing and test them on the paths that can
still run. Poison the URBs before freeing them: usb_poison_urb() waits
for a running completion handler and rejects any later submission, so
after it returns the input path is quiesced and only the rawmidi trigger
path can still reach bcd2000_midi_send(). No unpoison is needed; the
URBs are freed on the next line.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: wake linked drain waiters on unlink
snd_pcm_drain() on a linked stream parks an on-stack wait entry on the
drained peer's runtime->sleep, and after schedule_timeout() removes it
only if that peer is still found in the caller's group. If group
membership changes during the wait and the sleep ends by signal or
timeout (so autoremove_wake_function() does not run), finish_wait() is
skipped and snd_pcm_drain() returns with the entry still queued on that
stream's sleep list; a later wake_up() then walks a freed stack frame.
This is reachable by unlinking either the drained or the draining stream.
Unlike the close path (snd_pcm_drop() -> snd_pcm_post_stop()),
snd_pcm_unlink() never wakes the sleep queues. Wake every group member
under the group lock before the membership change, so a linked drainer is
released and drops its entry while the streams are still grouped.
The window was opened when snd_pcm_link_rwsem stopped being held across
the wait and the removal became conditional on group membership (see
Fixes). The later switch to finish_wait() kept that conditional removal,
so the signal/timeout case remained. |
| In the Linux kernel, the following vulnerability has been resolved:
ipvs: do not propagate one-packet flag to synced conns
Synced connections can be created before their destination exists. When
the destination is later added, ip_vs_bind_dest() copies connection flags
from the destination into cp->flags.
IP_VS_CONN_F_ONE_PACKET connections are not synced. If a synced
connection inherits IP_VS_CONN_F_ONE_PACKET while it is already hashed,
expiry can treat it as a one-packet connection and skip unlinking the
existing conn_tab node, leaving stale hash nodes pointing at a freed
struct ip_vs_conn.
Drop IP_VS_CONN_F_ONE_PACKET from destination flags when binding synced
connections. |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: re-fetch eth header after route_shortcircuit()
Before route_shortcircuit(), the eth header pointer is cached from eth_hdr(skb).
Inside route_shortcircuit(), pskb_may_pull() can be called, which may
reallocate skb->head.
In this case, returning to vxlan_xmit() leaves the cached eth pointer pointing to
freed memory, leading to a use-after-free when dereferencing eth->h_dest.
Fix this by updating eth = eth_hdr(skb) after calling route_shortcircuit(). |
| In the Linux kernel, the following vulnerability has been resolved:
veth: fix NAPI leak in XDP enable error path
During XDP enablement in veth, if xdp_rxq_info_reg() or
xdp_rxq_info_reg_mem_model() fails, the driver rolls back the changes.
However, the rollback loop:
for (i--; i >= start; i--) {
decrements the loop index 'i' before the first iteration. This
correctly skips unregistering the rxq for the failed index 'i' (as
registration failed or was already cleaned up), but it also
erroneously skips calling netif_napi_deli() for rq[i].xdp_napi.
Since netif_napi_add() was already called for index 'i', this leaves
a dangling napi_struct in the device's napi_list. When the veth
device is later destroyed, the freed queue memory (which contains the
leaked NAPI structure) can be reused.
The subsequent device teardown iterates the NAPI list and
corrupts the reallocated memory, leading to UAF.
Fix this by explicitly deleting the NAPI association for the failed
index 'i' before rolling back the successfully configured queues. |
| 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. |
