| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Use after free in Accessibility in Google Chrome on Windows prior to 147.0.7727.138 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: Critical) |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix trace_marker copy link list updates
When the "copy_trace_marker" option is enabled for an instance, anything
written into /sys/kernel/tracing/trace_marker is also copied into that
instances buffer. When the option is set, that instance's trace_array
descriptor is added to the marker_copies link list. This list is protected
by RCU, as all iterations uses an RCU protected list traversal.
When the instance is deleted, all the flags that were enabled are cleared.
This also clears the copy_trace_marker flag and removes the trace_array
descriptor from the list.
The issue is after the flags are called, a direct call to
update_marker_trace() is performed to clear the flag. This function
returns true if the state of the flag changed and false otherwise. If it
returns true here, synchronize_rcu() is called to make sure all readers
see that its removed from the list.
But since the flag was already cleared, the state does not change and the
synchronization is never called, leaving a possible UAF bug.
Move the clearing of all flags below the updating of the copy_trace_marker
option which then makes sure the synchronization is performed.
Also use the flag for checking the state in update_marker_trace() instead
of looking at if the list is empty. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/efa: Fix use of completion ctx after free
On admin queue completion handling, if the admin command completed with
error we print data from the completion context. The issue is that we
already freed the completion context in polling/interrupts handler which
means we print data from context in an unknown state (it might be
already used again).
Change the admin submission flow so alloc/dealloc of the context will be
symmetric and dealloc will be called after any potential use of the
context. |
| A flaw was found in virtio-win, specifically within the VirtIO Block (BLK) device. When the device undergoes a reset, it fails to properly manage memory, resulting in a use-after-free vulnerability. This issue could allow a local attacker to corrupt system memory, potentially leading to system instability or unexpected behavior. |
| In the Linux kernel, the following vulnerability has been resolved:
net: ti: icssg-prueth: fix use-after-free of CPPI descriptor in RX path
cppi5_hdesc_get_psdata() returns a pointer into the CPPI descriptor.
In both emac_rx_packet() and emac_rx_packet_zc(), the descriptor is
freed via k3_cppi_desc_pool_free() before the psdata pointer is used
by emac_rx_timestamp(), which dereferences psdata[0] and psdata[1].
This constitutes a use-after-free on every received packet that goes
through the timestamp path.
Defer the descriptor free until after all accesses through the psdata
pointer are complete. For emac_rx_packet(), move the free into the
requeue label so both early-exit and success paths free the descriptor
after all accesses are done. For emac_rx_packet_zc(), move the free to
the end of the loop body after emac_dispatch_skb_zc() (which calls
emac_rx_timestamp()) has returned. |
| In the Linux kernel, the following vulnerability has been resolved:
spi: spi-fsl-lpspi: fix teardown order issue (UAF)
There is a teardown order issue in the driver. The SPI controller is
registered using devm_spi_register_controller(), which delays
unregistration of the SPI controller until after the fsl_lpspi_remove()
function returns.
As the fsl_lpspi_remove() function synchronously tears down the DMA
channels, a running SPI transfer triggers the following NULL pointer
dereference due to use after free:
| fsl_lpspi 42550000.spi: I/O Error in DMA RX
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[...]
| Call trace:
| fsl_lpspi_dma_transfer+0x260/0x340 [spi_fsl_lpspi]
| fsl_lpspi_transfer_one+0x198/0x448 [spi_fsl_lpspi]
| spi_transfer_one_message+0x49c/0x7c8
| __spi_pump_transfer_message+0x120/0x420
| __spi_sync+0x2c4/0x520
| spi_sync+0x34/0x60
| spidev_message+0x20c/0x378 [spidev]
| spidev_ioctl+0x398/0x750 [spidev]
[...]
Switch from devm_spi_register_controller() to spi_register_controller() in
fsl_lpspi_probe() and add the corresponding spi_unregister_controller() in
fsl_lpspi_remove(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/pf: Fix use-after-free in migration restore
When an error is returned from xe_sriov_pf_migration_restore_produce(),
the data pointer is not set to NULL, which can trigger use-after-free
in subsequent .write() calls.
Set the pointer to NULL upon error to fix the problem.
(cherry picked from commit 4f53d8c6d23527d734fe3531d08e15cb170a0819) |
| Use after free in DevTools in Google Chrome prior to 147.0.7727.117 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High) |
| In the Linux kernel, the following vulnerability has been resolved:
media: verisilicon: Fix kernel panic due to __initconst misuse
Fix a kernel panic when probing the driver as a module:
Unable to handle kernel paging request at virtual address
ffffd9c18eb05000
of_find_matching_node_and_match+0x5c/0x1a0
hantro_probe+0x2f4/0x7d0 [hantro_vpu]
The imx8mq_vpu_shared_resources array is referenced by variant
structures through their shared_devices field. When built as a
module, __initconst causes this data to be freed after module
init, but it's later accessed during probe, causing a page fault.
The imx8mq_vpu_shared_resources is referenced from non-init code,
so keeping __initconst or __initconst_or_module here is wrong.
Drop the __initconst annotation and let it live in the normal .rodata
section.
A bug of __initconst called from regular non-init probe code
leading to bugs during probe deferrals or during unbind-bind cycles. |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (powerz) Fix use-after-free on USB disconnect
After powerz_disconnect() frees the URB and releases the mutex, a
subsequent powerz_read() call can acquire the mutex and call
powerz_read_data(), which dereferences the freed URB pointer.
Fix by:
- Setting priv->urb to NULL in powerz_disconnect() so that
powerz_read_data() can detect the disconnected state.
- Adding a !priv->urb check at the start of powerz_read_data()
to return -ENODEV on a disconnected device.
- Moving usb_set_intfdata() before hwmon registration so the
disconnect handler can always find the priv pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
media: mediatek: vcodec: fix use-after-free in encoder release path
The fops_vcodec_release() function frees the context structure (ctx)
without first cancelling any pending or running work in ctx->encode_work.
This creates a race window where the workqueue handler (mtk_venc_worker)
may still be accessing the context memory after it has been freed.
Race condition:
CPU 0 (release path) CPU 1 (workqueue)
--------------------- ------------------
fops_vcodec_release()
v4l2_m2m_ctx_release()
v4l2_m2m_cancel_job()
// waits for m2m job "done"
mtk_venc_worker()
v4l2_m2m_job_finish()
// m2m job "done"
// BUT worker still running!
// post-job_finish access:
other ctx dereferences
// UAF if ctx already freed
// returns (job "done")
kfree(ctx) // ctx freed
Root cause: The v4l2_m2m_ctx_release() only waits for the m2m job
lifecycle (via TRANS_RUNNING flag), not the workqueue lifecycle.
After v4l2_m2m_job_finish() is called, the m2m framework considers
the job complete and v4l2_m2m_ctx_release() returns, but the worker
function continues executing and may still access ctx.
The work is queued during encode operations via:
queue_work(ctx->dev->encode_workqueue, &ctx->encode_work)
The worker function accesses ctx->m2m_ctx, ctx->dev, and other ctx
fields even after calling v4l2_m2m_job_finish().
This vulnerability was confirmed with KASAN by running an instrumented
test module that widens the post-job_finish race window. KASAN detected:
BUG: KASAN: slab-use-after-free in mtk_venc_worker+0x159/0x180
Read of size 4 at addr ffff88800326e000 by task kworker/u8:0/12
Workqueue: mtk_vcodec_enc_wq mtk_venc_worker
Allocated by task 47:
__kasan_kmalloc+0x7f/0x90
fops_vcodec_open+0x85/0x1a0
Freed by task 47:
__kasan_slab_free+0x43/0x70
kfree+0xee/0x3a0
fops_vcodec_release+0xb7/0x190
Fix this by calling cancel_work_sync(&ctx->encode_work) before kfree(ctx).
This ensures the workqueue handler is both cancelled (if pending) and
synchronized (waits for any running handler to complete) before the
context is freed.
Placement rationale: The fix is placed after v4l2_ctrl_handler_free()
and before list_del_init(&ctx->list). At this point, all m2m operations
are done (v4l2_m2m_ctx_release() has returned), and we need to ensure
the workqueue is synchronized before removing ctx from the list and
freeing it.
Note: The open error path does NOT need cancel_work_sync() because
INIT_WORK() only initializes the work structure - it does not schedule
it. Work is only scheduled later during device_run() operations. |
| In the Linux kernel, the following vulnerability has been resolved:
net: lan966x: fix use-after-free and leak in lan966x_fdma_reload()
When lan966x_fdma_reload() fails to allocate new RX buffers, the restore
path restarts DMA using old descriptors whose pages were already freed
via lan966x_fdma_rx_free_pages(). Since page_pool_put_full_page() can
release pages back to the buddy allocator, the hardware may DMA into
memory now owned by other kernel subsystems.
Additionally, on the restore path, the newly created page pool (if
allocation partially succeeded) is overwritten without being destroyed,
leaking it.
Fix both issues by deferring the release of old pages until after the
new allocation succeeds. Save the old page array before the allocation
so old pages can be freed on the success path. On the failure path, the
old descriptors, pages and page pool are all still valid, making the
restore safe. Also ensure the restore path re-enables NAPI and wakes
the netdev, matching the success path. |
| In the Linux kernel, the following vulnerability has been resolved:
futex: Require sys_futex_requeue() to have identical flags
Nicholas reported that his LLM found it was possible to create a UaF
when sys_futex_requeue() is used with different flags. The initial
motivation for allowing different flags was the variable sized futex,
but since that hasn't been merged (yet), simply mandate the flags are
identical, as is the case for the old style sys_futex() requeue
operations. |
| In the Linux kernel, the following vulnerability has been resolved:
futex: Clear stale exiting pointer in futex_lock_pi() retry path
Fuzzying/stressing futexes triggered:
WARNING: kernel/futex/core.c:825 at wait_for_owner_exiting+0x7a/0x80, CPU#11: futex_lock_pi_s/524
When futex_lock_pi_atomic() sees the owner is exiting, it returns -EBUSY
and stores a refcounted task pointer in 'exiting'.
After wait_for_owner_exiting() consumes that reference, the local pointer
is never reset to nil. Upon a retry, if futex_lock_pi_atomic() returns a
different error, the bogus pointer is passed to wait_for_owner_exiting().
CPU0 CPU1 CPU2
futex_lock_pi(uaddr)
// acquires the PI futex
exit()
futex_cleanup_begin()
futex_state = EXITING;
futex_lock_pi(uaddr)
futex_lock_pi_atomic()
attach_to_pi_owner()
// observes EXITING
*exiting = owner; // takes ref
return -EBUSY
wait_for_owner_exiting(-EBUSY, owner)
put_task_struct(); // drops ref
// exiting still points to owner
goto retry;
futex_lock_pi_atomic()
lock_pi_update_atomic()
cmpxchg(uaddr)
*uaddr ^= WAITERS // whatever
// value changed
return -EAGAIN;
wait_for_owner_exiting(-EAGAIN, exiting) // stale
WARN_ON_ONCE(exiting)
Fix this by resetting upon retry, essentially aligning it with requeue_pi. |
| A use-after-free vulnerability was found in libxslt while parsing xsl nodes that may lead to the dereference of expired pointers and application crash. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_ct: fix use-after-free in timeout object destroy
nft_ct_timeout_obj_destroy() frees the timeout object with kfree()
immediately after nf_ct_untimeout(), without waiting for an RCU grace
period. Concurrent packet processing on other CPUs may still hold
RCU-protected references to the timeout object obtained via
rcu_dereference() in nf_ct_timeout_data().
Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer
freeing until after an RCU grace period, matching the approach already
used in nfnetlink_cttimeout.c.
KASAN report:
BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0
Read of size 4 at addr ffff8881035fe19c by task exploit/80
Call Trace:
nf_conntrack_tcp_packet+0x1381/0x29d0
nf_conntrack_in+0x612/0x8b0
nf_hook_slow+0x70/0x100
__ip_local_out+0x1b2/0x210
tcp_sendmsg_locked+0x722/0x1580
__sys_sendto+0x2d8/0x320
Allocated by task 75:
nft_ct_timeout_obj_init+0xf6/0x290
nft_obj_init+0x107/0x1b0
nf_tables_newobj+0x680/0x9c0
nfnetlink_rcv_batch+0xc29/0xe00
Freed by task 26:
nft_obj_destroy+0x3f/0xa0
nf_tables_trans_destroy_work+0x51c/0x5c0
process_one_work+0x2c4/0x5a0 |
| In the Linux kernel, the following vulnerability has been resolved:
net: shaper: protect late read accesses to the hierarchy
We look up a netdev during prep of Netlink ops (pre- callbacks)
and take a ref to it. Then later in the body of the callback
we take its lock or RCU which are the actual protections.
This is not proper, a conversion from a ref to a locked netdev
must include a liveness check (a check if the netdev hasn't been
unregistered already). Fix the read cases (those under RCU).
Writes needs a separate change to protect from creating the
hierarchy after flush has already run. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free of share_conf in compound request
smb2_get_ksmbd_tcon() reuses work->tcon in compound requests without
validating tcon->t_state. ksmbd_tree_conn_lookup() checks t_state ==
TREE_CONNECTED on the initial lookup path, but the compound reuse path
bypasses this check entirely.
If a prior command in the compound (SMB2_TREE_DISCONNECT) sets t_state
to TREE_DISCONNECTED and frees share_conf via ksmbd_share_config_put(),
subsequent commands dereference the freed share_conf through
work->tcon->share_conf.
KASAN report:
[ 4.144653] ==================================================================
[ 4.145059] BUG: KASAN: slab-use-after-free in smb2_write+0xc74/0xe70
[ 4.145415] Read of size 4 at addr ffff88810430c194 by task kworker/1:1/44
[ 4.145772]
[ 4.145867] CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted 7.0.0-rc3+ #60 PREEMPTLAZY
[ 4.145871] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 4.145875] Workqueue: ksmbd-io handle_ksmbd_work
[ 4.145888] Call Trace:
[ 4.145892] <TASK>
[ 4.145894] dump_stack_lvl+0x64/0x80
[ 4.145910] print_report+0xce/0x660
[ 4.145919] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 4.145928] ? smb2_write+0xc74/0xe70
[ 4.145931] kasan_report+0xce/0x100
[ 4.145934] ? smb2_write+0xc74/0xe70
[ 4.145937] smb2_write+0xc74/0xe70
[ 4.145939] ? __pfx_smb2_write+0x10/0x10
[ 4.145942] ? _raw_spin_unlock+0xe/0x30
[ 4.145945] ? ksmbd_smb2_check_message+0xeb2/0x24c0
[ 4.145948] ? smb2_tree_disconnect+0x31c/0x480
[ 4.145951] handle_ksmbd_work+0x40f/0x1080
[ 4.145953] process_one_work+0x5fa/0xef0
[ 4.145962] ? assign_work+0x122/0x3e0
[ 4.145964] worker_thread+0x54b/0xf70
[ 4.145967] ? __pfx_worker_thread+0x10/0x10
[ 4.145970] kthread+0x346/0x470
[ 4.145976] ? recalc_sigpending+0x19b/0x230
[ 4.145980] ? __pfx_kthread+0x10/0x10
[ 4.145984] ret_from_fork+0x4fb/0x6c0
[ 4.145992] ? __pfx_ret_from_fork+0x10/0x10
[ 4.145995] ? __switch_to+0x36c/0xbe0
[ 4.145999] ? __pfx_kthread+0x10/0x10
[ 4.146003] ret_from_fork_asm+0x1a/0x30
[ 4.146013] </TASK>
[ 4.146014]
[ 4.149858] Allocated by task 44:
[ 4.149953] kasan_save_stack+0x33/0x60
[ 4.150061] kasan_save_track+0x14/0x30
[ 4.150169] __kasan_kmalloc+0x8f/0xa0
[ 4.150274] ksmbd_share_config_get+0x1dd/0xdd0
[ 4.150401] ksmbd_tree_conn_connect+0x7e/0x600
[ 4.150529] smb2_tree_connect+0x2e6/0x1000
[ 4.150645] handle_ksmbd_work+0x40f/0x1080
[ 4.150761] process_one_work+0x5fa/0xef0
[ 4.150873] worker_thread+0x54b/0xf70
[ 4.150978] kthread+0x346/0x470
[ 4.151071] ret_from_fork+0x4fb/0x6c0
[ 4.151176] ret_from_fork_asm+0x1a/0x30
[ 4.151286]
[ 4.151332] Freed by task 44:
[ 4.151418] kasan_save_stack+0x33/0x60
[ 4.151526] kasan_save_track+0x14/0x30
[ 4.151634] kasan_save_free_info+0x3b/0x60
[ 4.151751] __kasan_slab_free+0x43/0x70
[ 4.151861] kfree+0x1ca/0x430
[ 4.151952] __ksmbd_tree_conn_disconnect+0xc8/0x190
[ 4.152088] smb2_tree_disconnect+0x1cd/0x480
[ 4.152211] handle_ksmbd_work+0x40f/0x1080
[ 4.152326] process_one_work+0x5fa/0xef0
[ 4.152438] worker_thread+0x54b/0xf70
[ 4.152545] kthread+0x346/0x470
[ 4.152638] ret_from_fork+0x4fb/0x6c0
[ 4.152743] ret_from_fork_asm+0x1a/0x30
[ 4.152853]
[ 4.152900] The buggy address belongs to the object at ffff88810430c180
[ 4.152900] which belongs to the cache kmalloc-96 of size 96
[ 4.153226] The buggy address is located 20 bytes inside of
[ 4.153226] freed 96-byte region [ffff88810430c180, ffff88810430c1e0)
[ 4.153549]
[ 4.153596] The buggy address belongs to the physical page:
[ 4.153750] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88810430ce80 pfn:0x10430c
[ 4.154000] flags: 0x
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in durable v2 replay of active file handles
parse_durable_handle_context() unconditionally assigns dh_info->fp->conn
to the current connection when handling a DURABLE_REQ_V2 context with
SMB2_FLAGS_REPLAY_OPERATION. ksmbd_lookup_fd_cguid() does not filter by
fp->conn, so it returns file handles that are already actively connected.
The unconditional overwrite replaces fp->conn, and when the overwriting
connection is subsequently freed, __ksmbd_close_fd() dereferences the
stale fp->conn via spin_lock(&fp->conn->llist_lock), causing a
use-after-free.
KASAN report:
[ 7.349357] ==================================================================
[ 7.349607] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x75/0xe0
[ 7.349811] Write of size 4 at addr ffff8881056ac18c by task kworker/1:2/108
[ 7.350010]
[ 7.350064] CPU: 1 UID: 0 PID: 108 Comm: kworker/1:2 Not tainted 7.0.0-rc3+ #58 PREEMPTLAZY
[ 7.350068] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 7.350070] Workqueue: ksmbd-io handle_ksmbd_work
[ 7.350083] Call Trace:
[ 7.350087] <TASK>
[ 7.350087] dump_stack_lvl+0x64/0x80
[ 7.350094] print_report+0xce/0x660
[ 7.350100] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 7.350101] ? __pfx___mod_timer+0x10/0x10
[ 7.350106] ? _raw_spin_lock+0x75/0xe0
[ 7.350108] kasan_report+0xce/0x100
[ 7.350109] ? _raw_spin_lock+0x75/0xe0
[ 7.350114] kasan_check_range+0x105/0x1b0
[ 7.350116] _raw_spin_lock+0x75/0xe0
[ 7.350118] ? __pfx__raw_spin_lock+0x10/0x10
[ 7.350119] ? __call_rcu_common.constprop.0+0x25e/0x780
[ 7.350125] ? close_id_del_oplock+0x2cc/0x4e0
[ 7.350128] __ksmbd_close_fd+0x27f/0xaf0
[ 7.350131] ksmbd_close_fd+0x135/0x1b0
[ 7.350133] smb2_close+0xb19/0x15b0
[ 7.350142] ? __pfx_smb2_close+0x10/0x10
[ 7.350143] ? xas_load+0x18/0x270
[ 7.350146] ? _raw_spin_lock+0x84/0xe0
[ 7.350148] ? __pfx__raw_spin_lock+0x10/0x10
[ 7.350150] ? _raw_spin_unlock+0xe/0x30
[ 7.350151] ? ksmbd_smb2_check_message+0xeb2/0x24c0
[ 7.350153] ? ksmbd_tree_conn_lookup+0xcd/0xf0
[ 7.350154] handle_ksmbd_work+0x40f/0x1080
[ 7.350156] process_one_work+0x5fa/0xef0
[ 7.350162] ? assign_work+0x122/0x3e0
[ 7.350163] worker_thread+0x54b/0xf70
[ 7.350165] ? __pfx_worker_thread+0x10/0x10
[ 7.350166] kthread+0x346/0x470
[ 7.350170] ? recalc_sigpending+0x19b/0x230
[ 7.350176] ? __pfx_kthread+0x10/0x10
[ 7.350178] ret_from_fork+0x4fb/0x6c0
[ 7.350183] ? __pfx_ret_from_fork+0x10/0x10
[ 7.350185] ? __switch_to+0x36c/0xbe0
[ 7.350188] ? __pfx_kthread+0x10/0x10
[ 7.350190] ret_from_fork_asm+0x1a/0x30
[ 7.350197] </TASK>
[ 7.350197]
[ 7.355160] Allocated by task 123:
[ 7.355261] kasan_save_stack+0x33/0x60
[ 7.355373] kasan_save_track+0x14/0x30
[ 7.355484] __kasan_kmalloc+0x8f/0xa0
[ 7.355593] ksmbd_conn_alloc+0x44/0x6d0
[ 7.355711] ksmbd_kthread_fn+0x243/0xd70
[ 7.355839] kthread+0x346/0x470
[ 7.355942] ret_from_fork+0x4fb/0x6c0
[ 7.356051] ret_from_fork_asm+0x1a/0x30
[ 7.356164]
[ 7.356214] Freed by task 134:
[ 7.356305] kasan_save_stack+0x33/0x60
[ 7.356416] kasan_save_track+0x14/0x30
[ 7.356527] kasan_save_free_info+0x3b/0x60
[ 7.356646] __kasan_slab_free+0x43/0x70
[ 7.356761] kfree+0x1ca/0x430
[ 7.356862] ksmbd_tcp_disconnect+0x59/0xe0
[ 7.356993] ksmbd_conn_handler_loop+0x77e/0xd40
[ 7.357138] kthread+0x346/0x470
[ 7.357240] ret_from_fork+0x4fb/0x6c0
[ 7.357350] ret_from_fork_asm+0x1a/0x30
[ 7.357463]
[ 7.357513] The buggy address belongs to the object at ffff8881056ac000
[ 7.357513] which belongs to the cache kmalloc-1k of size 1024
[ 7.357857] The buggy address is located 396 bytes inside of
[ 7.357857] freed 1024-byte region
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
bridge: cfm: Fix race condition in peer_mep deletion
When a peer MEP is being deleted, cancel_delayed_work_sync() is called
on ccm_rx_dwork before freeing. However, br_cfm_frame_rx() runs in
softirq context under rcu_read_lock (without RTNL) and can re-schedule
ccm_rx_dwork via ccm_rx_timer_start() between cancel_delayed_work_sync()
returning and kfree_rcu() being called.
The following is a simple race scenario:
cpu0 cpu1
mep_delete_implementation()
cancel_delayed_work_sync(ccm_rx_dwork);
br_cfm_frame_rx()
// peer_mep still in hlist
if (peer_mep->ccm_defect)
ccm_rx_timer_start()
queue_delayed_work(ccm_rx_dwork)
hlist_del_rcu(&peer_mep->head);
kfree_rcu(peer_mep, rcu);
ccm_rx_work_expired()
// on freed peer_mep
To prevent this, cancel_delayed_work_sync() is replaced with
disable_delayed_work_sync() in both peer MEP deletion paths, so
that subsequent queue_delayed_work() calls from br_cfm_frame_rx()
are silently rejected.
The cc_peer_disable() helper retains cancel_delayed_work_sync()
because it is also used for the CC enable/disable toggle path where
the work must remain re-schedulable. |
