| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
bridge: stp: Fix a potential use-after-free when deleting a bridge
The three STP timers are not supposed to be armed while the bridge is
administratively down. They are synchronously deactivated when the
bridge is put administratively down and the various call sites check for
'IFF_UP' before arming them.
This check is missing from br_topology_change_detection() and it is
possible to engineer a situation in which the topology change timer is
armed while the bridge is administratively down, resulting in a
use-after-free [1] when the bridge is deleted.
Fix by adding the missing check and for good measures synchronously
shutdown the three timers when the bridge is deleted.
[1]
ODEBUG: free active (active state 0) object: ffff88811662b9b0 object type: timer_list hint: br_topology_change_timer_expired (net/bridge/br_stp_timer.c:120)
WARNING: lib/debugobjects.c:629 at debug_print_object+0x1bc/0x450, CPU#9: ip/359 |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF
The teql master->slaves singly linked list is not protected against
multiple writes. It can be mod'ed concurently from teql_master_xmit(),
teql_dequeue(), teql_init() and teql_destroy() without holding any list
lock or RCU protection.
zdi-disclosures@trendmicro.com has demonstrated that the qdisc is freed
after an RCU grace period, but teql_master_xmit() running on another
CPU can still hold a stale pointer into the list, resulting in a
slab-use-after-free:
BUG: KASAN: slab-use-after-free in teql_master_xmit+0xf0f/0x16b0
Read of size 8 at addr ffff888013fb0440 by task poc/332
Freed 512-byte region [ffff888013fb0400, ffff888013fb0600) (kmalloc-512)
The fix?
Add a per-master slaves_lock spinlock that serializes all mutations of
master->slaves and the NEXT_SLAVE() links in teql_destroy() and
teql_qdisc_init(). teql_master_xmit() also takes the same slaves_lock
around those updates.
Annotate master->slaves and the per-slave ->next pointer with __rcu and
use the appropriate RCU accessors everywhere they are touched:
rcu_assign_pointer() on the writer side (under slaves_lock),
rcu_dereference_protected() for the writer-side loads (also under
slaves_lock), rcu_dereference_bh() for the loads in teql_master_xmit() and
rtnl_dereference() for the loads in teql_master_open()/teql_master_mtu(),
which run under RTNL.
Pair this with rcu_read_lock_bh()/rcu_read_unlock_bh() around the list
traversal in teql_master_xmit(), so that readers either observe a fully
linked list or are deferred until the in-flight mutation completes. The two
early-return paths in teql_master_xmit() are updated to release the RCU-bh
read-side critical section before returning, since leaving it held would
disable BH on that CPU for good. |
| In the Linux kernel, the following vulnerability has been resolved:
eth: fbnic: don't cache shinfo across skb realloc
fbnic_tx_lso() calls skb_cow_head() which may reallocate the skb
including the shared info. We can't use the pointer calculated
before the call.
BUG: KASAN: slab-use-after-free in fbnic_tx_lso.isra.0+0x668/0x8e0
Read of size 4 at addr ff110000262edd98 by task swapper/5/0
Call Trace:
fbnic_tx_lso.isra.0+0x668/0x8e0
fbnic_xmit_frame+0x622/0xba0
dev_hard_start_xmit+0xf4/0x620
Allocated by task 8653:
__alloc_skb+0x11e/0x5f0
alloc_skb_with_frags+0xcc/0x6c0
sock_alloc_send_pskb+0x327/0x3f0
__ip_append_data+0x188b/0x47a0
ip_make_skb+0x24a/0x300
udp_sendmsg+0x14d2/0x21e0
Freed by task 0:
kfree+0x123/0x5a0
pskb_expand_head+0x36c/0xfa0
fbnic_tx_lso.isra.0+0x500/0x8e0
fbnic_xmit_frame+0x622/0xba0
dev_hard_start_xmit+0xf4/0x620
sch_direct_xmit+0x25b/0x1100
The buggy address belongs to the object at ff110000262edc40
which belongs to the cache skbuff_small_head of size 640
The buggy address is located 344 bytes inside of
freed 640-byte region [ff110000262edc40, ff110000262ede |
| In the Linux kernel, the following vulnerability has been resolved:
alloc_tag: fix use-after-free in /proc/allocinfo after module unload
allocinfo_start() only reinitializes the codetag iterator at position 0.
For subsequent reads (position > 0), it reuses cached iterator state from
the previous batch. allocinfo_stop() drops mod_lock between read batches,
which allows module unload to complete and free the module memory that the
cached iterator still references:
CPU0 (read) CPU1 (rmmod)
---- ----
allocinfo_start(pos=0)
down_read(mod_lock)
allocinfo_show()
...
allocinfo_stop()
up_read(mod_lock)
codetag_unload_module()
kfree(cmod)
release_module_tags()
...
free_mod_mem()
allocinfo_start(pos=N)
down_read(mod_lock)
// reuses cached iter, skips re-init
allocinfo_show()
ct->filename <-- UAF
After free_mod_mem() frees the module's .rodata, allocinfo_show()
dereferences ct->filename, ct->function which point there.
Save the iterator state in allocinfo_next() and resume from it in
allocinfo_start() with codetag_next_ct(), which detects module removal via
idr_find() returning NULL and skips to the next module. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Kill MIDI 2.0 URBs before freeing endpoints
MIDI 2.0 input URBs are started during snd_usb_midi_v2_create(). A
later setup failure can still jump to snd_usb_midi_v2_free(), which
currently frees each endpoint and its coherent URB buffers without first
stopping the submitted URBs. A completion can then dereference the
embedded URB context and endpoint state after they have been freed, or
try to resubmit from the stale endpoint.
This was observed as a KASAN slab-use-after-free in
input_urb_complete().
The buggy scenario involves two paths, with each column showing the order
within that path:
probe error path: USB completion path:
1. start_input_streams() submits 1. The HCD still owns a
input URBs. submitted input URB.
2. A later setup helper returns 2. input_urb_complete() runs
an error. with urb->context in ep.
3. snd_usb_midi_v2_free() frees 3. The completion reads ep
endpoint storage and URB buffers. state and can requeue URBs.
Make the endpoint destructor follow the same teardown ordering used for
disconnect when the endpoint has not already been disconnected: publish
ep->disconnected, kill the URBs synchronously, and drain the endpoint
before freeing URB buffers and endpoint storage. The guard avoids
repeating the stop sequence after the normal
snd_usb_midi_v2_disconnect_all() path, while still synchronizing the
direct MIDI 2.0 create-error free path.
Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in input_urb_complete+0x37/0x1b0
Workqueue: usb_hub_wq hub_event
RIP: 0010:_raw_spin_unlock_irq+0x2e/0x50
Read of size 8
Call trace:
dump_stack_lvl+0x77/0xb0
print_report+0xce/0x5f0
input_urb_complete+0x37/0x1b0 (sound/usb/midi2.c:186)
srso_alias_return_thunk+0x5/0xfbef5
__virt_addr_valid+0x19f/0x330
kasan_report+0xe0/0x110
__usb_hcd_giveback_urb+0x112/0x1d0
dummy_timer+0xaaa/0x19a0
lock_is_held_type+0x9a/0x110
__lock_acquire+0x467/0x28b0
mark_held_locks+0x40/0x70
_raw_spin_unlock_irqrestore+0x44/0x60
lockdep_hardirqs_on_prepare+0xbb/0x1a0
__hrtimer_run_queues+0x101/0x520
hrtimer_run_softirq+0xd0/0x130
handle_softirqs+0x15b/0x670
__irq_exit_rcu+0xd0/0x170
irq_exit_rcu+0xe/0x20
sysvec_apic_timer_interrupt+0x6c/0x80
asm_sysvec_apic_timer_interrupt+0x1a/0x20 |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: Fix dev use-after-free in xfrm async resumption
xfrm async resumption hold skb->dev refcnt until after transport_finish.
However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking
device reference, such as vti_rcv_cb. The subsequent async resumption
will decrement the tunnel device's reference count, which lead to uaf
of tunnel dev and refcnt leak of orig dev as below:
unregister_netdevice: waiting for vti1 to become free. Usage count = -2
Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set
by xfrm_rcv_cb can race with device teardown. Extend rcu protection over
xfrm_rcv_cb and transport_finish to prevent races. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()
Sashiko pointed out that kfree_rcu() was called before
rcu_assign_pointer() in handling the comment extension.
Fix the order so that rcu_assign_pointer() called first. |
| In the Linux kernel, the following vulnerability has been resolved:
staging: nvec: fix use-after-free in nvec_rx_completed()
In nvec_rx_completed(), when an incomplete RX transfer is detected,
nvec_msg_free() is called to return the message back to the pool by
clearing its 'used' atomic flag. Immediately after this, the code
accesses nvec->rx->data[0] to check the message type.
Since nvec_msg_free() marks the pool slot as available via atomic_set(),
any concurrent or subsequent call to nvec_msg_alloc() could claim that
same slot and overwrite its data[] array. Reading nvec->rx->data[0] after
freeing the message is therefore a use-after-free.
Fix this by saving the message type byte before calling nvec_msg_free(),
then using the saved value for the battery quirk check. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: Free CQ toggle page after firmware teardown
Free the toggle page only after firmware teardown completes so that
an NQ interrupt arriving during bnxt_qplib_destroy_cq() won't write
the toggle value to an already-freed page. Move free_page() after
bnxt_qplib_destroy_cq. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: fix refcounting of iso_conn
iso_conn_del() and iso_chan_del() have a race that results to double-put
of iso_conn:
[Task hdev->workqueue] [Task 2]
iso_conn_del iso_chan_del
iso_conn_hold_unless_zero iso_conn_lock
iso_conn_lock conn->sk = NULL
iso_conn_unlock
sk = iso_sock_hold(conn) <---------ยด
if (!sk) iso_conn_put iso_conn_put
iso_conn_put /* UAF */
The extra put for !sk in iso_conn_del() is currently required since
failing iso_chan_add() may leave iso_conn not associated with any sk.
Fix by having iso_pi(sk)->conn own refcount when non-NULL, so
iso_conn_del does not need to put it. Adjust the iso_conn_add()
refcounting so that conn is put if it does not get associated with an
sk. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: Free SRQ toggle page after firmware teardown
Free the toggle page only after firmware teardown completes so that
an NQ interrupt arriving during bnxt_qplib_destroy_srq() won't write
the toggle values to an already-freed page. Move free_page() after
bnxt_qplib_destroy_srq(). |
| In the Linux kernel, the following vulnerability has been resolved:
net: watchdog: fix refcount tracking races
Blamed commit converted the untracked dev_hold()/dev_put() calls
in the watchdog code to use the tracked dev_hold_track()/dev_put_track()
(which were later renamed/interfaced to netdev_hold() and netdev_put()).
By introducing dev->watchdog_dev_tracker to store the
reference tracking information without adding synchronization
between netdev_watchdog_up() and dev_watchdog(), it enabled the
race condition where this pointer could be overwritten or freed
concurrently, leading to the list corruption crash syzbot reported:
list_del corruption, ffff888114a18c00->next is NULL
kernel BUG at lib/list_debug.c:52 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 91 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound linkwatch_event
RIP: 0010:__list_del_entry_valid_or_report.cold+0x22/0x2a lib/list_debug.c:52
Call Trace:
<TASK>
__list_del_entry_valid include/linux/list.h:132 [inline]
__list_del_entry include/linux/list.h:246 [inline]
list_move_tail include/linux/list.h:341 [inline]
ref_tracker_free+0x1a7/0x6c0 lib/ref_tracker.c:329
netdev_tracker_free include/linux/netdevice.h:4491 [inline]
netdev_put include/linux/netdevice.h:4508 [inline]
netdev_put include/linux/netdevice.h:4504 [inline]
netdev_watchdog_down net/sched/sch_generic.c:600 [inline]
dev_deactivate_many+0x28c/0xfe0 net/sched/sch_generic.c:1363
dev_deactivate+0x109/0x1d0 net/sched/sch_generic.c:1397
linkwatch_do_dev net/core/link_watch.c:184 [inline]
linkwatch_do_dev+0xd3/0x120 net/core/link_watch.c:166
__linkwatch_run_queue+0x3a5/0x810 net/core/link_watch.c:240
linkwatch_event+0x8f/0xc0 net/core/link_watch.c:314
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
This patch has three coordinated parts:
1) Add dev->watchdog_lock and dev->watchdog_ref_held to serialize watchdog operations.
2) Remove netdev_watchdog_up() call from netif_carrier_on():
This ensures netdev_watchdog_up() is only called from process/BH context
(via linkwatch workqueue dev_activate()), allowing us to use
spin_lock_bh() for synchronization.
3) Synchronize watchdog up and watchdog timer:
Protect netdev_watchdog_up() with tx_global_lock and watchdog_lock.
Only allocate a new tracker in netdev_watchdog_up() if one is
not already present.
In dev_watchdog(), ensure we don't release the tracker if the
timer was rescheduled either by dev_watchdog() itself or concurrently
by netdev_watchdog_up(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp
l2cap_le_connect_rsp() obtains a channel via
__l2cap_get_chan_by_ident() but neither holds a reference nor uses
l2cap_chan_hold_unless_zero() before locking and operating on it.
A concurrent l2cap_chan_del() triggered by a remote disconnect can
free the channel between the lookup and l2cap_chan_lock(), causing
a use-after-free.
The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler
l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()
to safely hold a reference, but l2cap_le_connect_rsp() was left
unprotected.
Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup
and l2cap_chan_put() on the exit path, consistent with other L2CAP
response handlers. |
| 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:
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:
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. |
| In the Linux kernel, the following vulnerability has been resolved:
net: Stop leased rxq before uninstalling its memory provider
netif_rxq_cleanup_unlease() tears down the memory provider that was
installed on a physical RX queue through a netkit queue lease. It
currently revokes the provider's DMA mappings before stopping the
physical queue:
__netif_mp_uninstall_rxq(virt_rxq, p); /* DMA unmap */
__netif_mp_close_rxq(phys_rxq->dev, rxq_idx, p); /* queue stop */
This inverts the ordering used by the regular teardown paths (normal
device unregister and the io_uring zcrx close path), which stop the
queue before revoking the provider's mappings.
With the physical queue still live, its NAPI can keep consuming
net_iov entries from the page_pool alloc cache after the
__netif_mp_uninstall_rxq() has already cleared their dma_addr,
opening a window for the device to DMA to a stale or zero address.
Fix it by swapping the two calls so the queue is stopped (and its
NAPI quiesced) before the provider is uninstalled. No functional
regression was observed across repeated runs of the nk_qlease.py
HW selftest, which exercises the lease teardown path; this was
tested against fbnic QEMU emulation. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: fib: Don't dump dying fib_info in fib_leaf_notify().
syzbot reported use-after-free in nsim_fib4_prepare_event(). [0]
The problem is that the following functions call fib_info_hold() /
refcount_inc() while dumping fib_info under RCU, which is unsafe.
* mlxsw_sp_router_fib4_event()
* rocker_router_fib_event()
* nsim_fib4_prepare_event()
refcount_inc_not_zero() must be used, but it would be too late
there.
Let's guarantee the lifetime of fib_info in fib_leaf_notify().
Note that IPv6 does not need the corresponding change since
fib6_table_dump() holds fib6_table.tb6_lock.
[0]:
refcount_t: addition on 0; use-after-free.
WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x9f/0x110 lib/refcount.c:25, CPU#0: kworker/u8:15/3420
Modules linked in:
CPU: 0 UID: 0 PID: 3420 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
RIP: 0010:refcount_warn_saturate+0x9f/0x110 lib/refcount.c:25
Code: eb 66 85 db 74 3e 83 fb 01 75 4c e8 1b f1 22 fd 48 8d 3d 84 cb f1 0a 67 48 0f b9 3a eb 4a e8 08 f1 22 fd 48 8d 3d 81 cb f1 0a <67> 48 0f b9 3a eb 37 e8 f5 f0 22 fd 48 8d 3d 7e cb f1 0a 67 48 0f
RSP: 0018:ffffc9000f2c7270 EFLAGS: 00010293
RAX: ffffffff84a18858 RBX: 0000000000000002 RCX: ffff888032ff9ec0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8f9353e0
RBP: 0000000000000000 R08: ffff888032ff9ec0 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880570cc000
R13: dffffc0000000000 R14: ffff88802b40563c R15: ffff8880570cc000
FS: 0000000000000000(0000) GS:ffff888126173000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb1f4d5d000 CR3: 000000006072a000 CR4: 00000000003526f0
Call Trace:
<TASK>
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
fib_info_hold include/net/ip_fib.h:629 [inline]
nsim_fib4_prepare_event drivers/net/netdevsim/fib.c:930 [inline]
nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1000 [inline]
nsim_fib_event_nb+0x1055/0x1240 drivers/net/netdevsim/fib.c:1043
call_fib_notifier+0x45/0x80 net/core/fib_notifier.c:25
call_fib_entry_notifier net/ipv4/fib_trie.c:90 [inline]
fib_leaf_notify net/ipv4/fib_trie.c:2176 [inline]
fib_table_notify net/ipv4/fib_trie.c:2194 [inline]
fib_notify+0x36b/0x5e0 net/ipv4/fib_trie.c:2217
fib_net_dump net/core/fib_notifier.c:70 [inline]
register_fib_notifier+0x184/0x360 net/core/fib_notifier.c:108
nsim_fib_create+0x85d/0x9f0 drivers/net/netdevsim/fib.c:1596
nsim_dev_reload_create drivers/net/netdevsim/dev.c:1604 [inline]
nsim_dev_reload_up+0x374/0x7c0 drivers/net/netdevsim/dev.c:1058
devlink_reload+0x501/0x8d0 net/devlink/dev.c:475
devlink_pernet_pre_exit+0x1ff/0x420 net/devlink/core.c:558
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x187/0x940 net/core/net_namespace.c:234
cleanup_net+0x56e/0x800 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix UAF in hci_unregister_dev()
hci_unregister_dev() does not disable cmd_timer and ncmd_timer
before the hci_dev structure is freed. If a timeout fires
during device teardown, the callback dereferences freed memory
(including the hdev->reset function pointer), leading to a
use-after-free.
Add disable_delayed_work_sync() calls alongside the existing
disable_work_sync() calls to ensure both timers are fully
quiesced before teardown proceeds. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: rebase copied fsdlm LVB pointers in locking_state
The locking_state debugfs iterator snapshots struct ocfs2_lock_res by
value under ocfs2_dlm_tracking_lock and later formats that copy in
ocfs2_dlm_seq_show(). That is fine for the inline fields, but the
userspace fsdlm stack stores the LVB through lksb_fsdlm.sb_lvbptr. Once
the iterator drops the tracking lock, a copied non-NULL sb_lvbptr still
points into the original lockres owner, so teardown can free that
container before the debugfs dump walks the raw LVB bytes.
Rebase the copied sb_lvbptr to the copied l_lksb before dumping the raw
LVB. The seq snapshot already carries the inline LVB storage reserved in
struct ocfs2_dlm_lksb, so the debugfs reader can dump the copied bytes
without borrowing the original lockres lifetime.
The buggy scenario involves two paths, with each column showing the order
within that path:
locking_state reader: lockres teardown:
1. ocfs2_dlm_seq_start()/next() 1. file release or another owner
copies struct ocfs2_lock_res teardown reaches
2. ocfs2_dlm_seq_show() formats ocfs2_lock_res_free()
the copied row 2. the lockres is removed from the
3. ocfs2_dlm_lvb() follows the tracking list
copied sb_lvbptr 3. the owner frees the original
lockres container
Validation reproduced this kernel report:
KASAN slab-use-after-free in ocfs2_dlm_seq_show+0x1bd/0x430
RIP: 0033:0x7f8ec4b1e29d
The buggy address belongs to the object at ffff88810a1e0800 which belongs
to the cache kmalloc-1k of size 1024
The buggy address is located 368 bytes inside of freed 1024-byte region
[ffff88810a1e0800, ffff88810a1e0c00)
Read of size 1
Call trace:
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
ocfs2_dlm_seq_show+0x1bd/0x430 (fs/ocfs2/dlmglue.c:3137)
srso_alias_return_thunk+0x5/0xfbef5
__virt_addr_valid+0x19f/0x330
kasan_report+0xe0/0x110
seq_read_iter+0x29d/0x790
seq_read+0x20a/0x280
find_held_lock+0x2b/0x80
rcu_read_unlock+0x18/0x70
full_proxy_read+0x9e/0xd0
vfs_read+0x12c/0x590
ksys_read+0xd2/0x170
do_user_addr_fault+0x65a/0x890
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Allocated by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
ocfs2_file_open+0x13e/0x300
do_dentry_open+0x233/0x7f0
vfs_open+0x5a/0x1b0
path_openat+0x66d/0x1540
do_file_open+0x186/0x2b0
do_sys_openat2+0xce/0x150
__x64_sys_openat+0xd0/0x140
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x313/0x590
ocfs2_file_release+0x138/0x260
__fput+0x1df/0x4b0
fput_close_sync+0xd2/0x170
__x64_sys_close+0x55/0x90
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f |
