Security Vulnerabilities
- CVEs Published In July 2024
In the Linux kernel, the following vulnerability has been resolved:
ax25: Fix refcount imbalance on inbound connections
When releasing a socket in ax25_release(), we call netdev_put() to
decrease the refcount on the associated ax.25 device. However, the
execution path for accepting an incoming connection never calls
netdev_hold(). This imbalance leads to refcount errors, and ultimately
to kernel crashes.
A typical call trace for the above situation will start with one of the
following errors:
refcount_t: decrement hit 0; leaking memory.
refcount_t: underflow; use-after-free.
And will then have a trace like:
Call Trace:
<TASK>
? show_regs+0x64/0x70
? __warn+0x83/0x120
? refcount_warn_saturate+0xb2/0x100
? report_bug+0x158/0x190
? prb_read_valid+0x20/0x30
? handle_bug+0x3e/0x70
? exc_invalid_op+0x1c/0x70
? asm_exc_invalid_op+0x1f/0x30
? refcount_warn_saturate+0xb2/0x100
? refcount_warn_saturate+0xb2/0x100
ax25_release+0x2ad/0x360
__sock_release+0x35/0xa0
sock_close+0x19/0x20
[...]
On reboot (or any attempt to remove the interface), the kernel gets
stuck in an infinite loop:
unregister_netdevice: waiting for ax0 to become free. Usage count = 0
This patch corrects these issues by ensuring that we call netdev_hold()
and ax25_dev_hold() for new connections in ax25_accept(). This makes the
logic leading to ax25_accept() match the logic for ax25_bind(): in both
cases we increment the refcount, which is ultimately decremented in
ax25_release().
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: Lock wiphy in cfg80211_get_station
Wiphy should be locked before calling rdev_get_station() (see lockdep
assert in ieee80211_get_station()).
This fixes the following kernel NULL dereference:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000003001000
[0000000000000050] pgd=0800000002dca003, p4d=0800000002dca003, pud=08000000028e9003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] SMP
Modules linked in: netconsole dwc3_meson_g12a dwc3_of_simple dwc3 ip_gre gre ath10k_pci ath10k_core ath9k ath9k_common ath9k_hw ath
CPU: 0 PID: 1091 Comm: kworker/u8:0 Not tainted 6.4.0-02144-g565f9a3a7911-dirty #705
Hardware name: RPT (r1) (DT)
Workqueue: bat_events batadv_v_elp_throughput_metric_update
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ath10k_sta_statistics+0x10/0x2dc [ath10k_core]
lr : sta_set_sinfo+0xcc/0xbd4
sp : ffff000007b43ad0
x29: ffff000007b43ad0 x28: ffff0000071fa900 x27: ffff00000294ca98
x26: ffff000006830880 x25: ffff000006830880 x24: ffff00000294c000
x23: 0000000000000001 x22: ffff000007b43c90 x21: ffff800008898acc
x20: ffff00000294c6e8 x19: ffff000007b43c90 x18: 0000000000000000
x17: 445946354d552d78 x16: 62661f7200000000 x15: 57464f445946354d
x14: 0000000000000000 x13: 00000000000000e3 x12: d5f0acbcebea978e
x11: 00000000000000e3 x10: 000000010048fe41 x9 : 0000000000000000
x8 : ffff000007b43d90 x7 : 000000007a1e2125 x6 : 0000000000000000
x5 : ffff0000024e0900 x4 : ffff800000a0250c x3 : ffff000007b43c90
x2 : ffff00000294ca98 x1 : ffff000006831920 x0 : 0000000000000000
Call trace:
ath10k_sta_statistics+0x10/0x2dc [ath10k_core]
sta_set_sinfo+0xcc/0xbd4
ieee80211_get_station+0x2c/0x44
cfg80211_get_station+0x80/0x154
batadv_v_elp_get_throughput+0x138/0x1fc
batadv_v_elp_throughput_metric_update+0x1c/0xa4
process_one_work+0x1ec/0x414
worker_thread+0x70/0x46c
kthread+0xdc/0xe0
ret_from_fork+0x10/0x20
Code: a9bb7bfd 910003fd a90153f3 f9411c40 (f9402814)
This happens because STA has time to disconnect and reconnect before
batadv_v_elp_throughput_metric_update() delayed work gets scheduled. In
this situation, ath10k_sta_state() can be in the middle of resetting
arsta data when the work queue get chance to be scheduled and ends up
accessing it. Locking wiphy prevents that.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: Fix deadlock in ieee80211_sta_ps_deliver_wakeup()
The ieee80211_sta_ps_deliver_wakeup() function takes sta->ps_lock to
synchronizes with ieee80211_tx_h_unicast_ps_buf() which is called from
softirq context. However using only spin_lock() to get sta->ps_lock in
ieee80211_sta_ps_deliver_wakeup() does not prevent softirq to execute
on this same CPU, to run ieee80211_tx_h_unicast_ps_buf() and try to
take this same lock ending in deadlock. Below is an example of rcu stall
that arises in such situation.
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 2-....: (42413413 ticks this GP) idle=b154/1/0x4000000000000000 softirq=1763/1765 fqs=21206996
rcu: (t=42586894 jiffies g=2057 q=362405 ncpus=4)
CPU: 2 PID: 719 Comm: wpa_supplicant Tainted: G W 6.4.0-02158-g1b062f552873 #742
Hardware name: RPT (r1) (DT)
pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : queued_spin_lock_slowpath+0x58/0x2d0
lr : invoke_tx_handlers_early+0x5b4/0x5c0
sp : ffff00001ef64660
x29: ffff00001ef64660 x28: ffff000009bc1070 x27: ffff000009bc0ad8
x26: ffff000009bc0900 x25: ffff00001ef647a8 x24: 0000000000000000
x23: ffff000009bc0900 x22: ffff000009bc0900 x21: ffff00000ac0e000
x20: ffff00000a279e00 x19: ffff00001ef646e8 x18: 0000000000000000
x17: ffff800016468000 x16: ffff00001ef608c0 x15: 0010533c93f64f80
x14: 0010395c9faa3946 x13: 0000000000000000 x12: 00000000fa83b2da
x11: 000000012edeceea x10: ffff0000010fbe00 x9 : 0000000000895440
x8 : 000000000010533c x7 : ffff00000ad8b740 x6 : ffff00000c350880
x5 : 0000000000000007 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff00000ac0e0e8
Call trace:
queued_spin_lock_slowpath+0x58/0x2d0
ieee80211_tx+0x80/0x12c
ieee80211_tx_pending+0x110/0x278
tasklet_action_common.constprop.0+0x10c/0x144
tasklet_action+0x20/0x28
_stext+0x11c/0x284
____do_softirq+0xc/0x14
call_on_irq_stack+0x24/0x34
do_softirq_own_stack+0x18/0x20
do_softirq+0x74/0x7c
__local_bh_enable_ip+0xa0/0xa4
_ieee80211_wake_txqs+0x3b0/0x4b8
__ieee80211_wake_queue+0x12c/0x168
ieee80211_add_pending_skbs+0xec/0x138
ieee80211_sta_ps_deliver_wakeup+0x2a4/0x480
ieee80211_mps_sta_status_update.part.0+0xd8/0x11c
ieee80211_mps_sta_status_update+0x18/0x24
sta_apply_parameters+0x3bc/0x4c0
ieee80211_change_station+0x1b8/0x2dc
nl80211_set_station+0x444/0x49c
genl_family_rcv_msg_doit.isra.0+0xa4/0xfc
genl_rcv_msg+0x1b0/0x244
netlink_rcv_skb+0x38/0x10c
genl_rcv+0x34/0x48
netlink_unicast+0x254/0x2bc
netlink_sendmsg+0x190/0x3b4
____sys_sendmsg+0x1e8/0x218
___sys_sendmsg+0x68/0x8c
__sys_sendmsg+0x44/0x84
__arm64_sys_sendmsg+0x20/0x28
do_el0_svc+0x6c/0xe8
el0_svc+0x14/0x48
el0t_64_sync_handler+0xb0/0xb4
el0t_64_sync+0x14c/0x150
Using spin_lock_bh()/spin_unlock_bh() instead prevents softirq to raise
on the same CPU that is holding the lock.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: defer exposing anon_fd until after copy_to_user() succeeds
After installing the anonymous fd, we can now see it in userland and close
it. However, at this point we may not have gotten the reference count of
the cache, but we will put it during colse fd, so this may cause a cache
UAF.
So grab the cache reference count before fd_install(). In addition, by
kernel convention, fd is taken over by the user land after fd_install(),
and the kernel should not call close_fd() after that, i.e., it should call
fd_install() after everything is ready, thus fd_install() is called after
copy_to_user() succeeds.
In the Linux kernel, the following vulnerability has been resolved:
mm/huge_memory: don't unpoison huge_zero_folio
When I did memory failure tests recently, below panic occurs:
kernel BUG at include/linux/mm.h:1135!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14
RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0
Call Trace:
<TASK>
do_shrink_slab+0x14f/0x6a0
shrink_slab+0xca/0x8c0
shrink_node+0x2d0/0x7d0
balance_pgdat+0x33a/0x720
kswapd+0x1f3/0x410
kthread+0xd5/0x100
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
Modules linked in: mce_inject hwpoison_inject
---[ end trace 0000000000000000 ]---
RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0
The root cause is that HWPoison flag will be set for huge_zero_folio
without increasing the folio refcnt. But then unpoison_memory() will
decrease the folio refcnt unexpectedly as it appears like a successfully
hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when
releasing huge_zero_folio.
Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue.
We're not prepared to unpoison huge_zero_folio yet.
In the Linux kernel, the following vulnerability has been resolved:
riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context
__kernel_map_pages() is a debug function which clears the valid bit in page
table entry for deallocated pages to detect illegal memory accesses to
freed pages.
This function set/clear the valid bit using __set_memory(). __set_memory()
acquires init_mm's semaphore, and this operation may sleep. This is
problematic, because __kernel_map_pages() can be called in atomic context,
and thus is illegal to sleep. An example warning that this causes:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd
preempt_count: 2, expected: 0
CPU: 0 PID: 2 Comm: kthreadd Not tainted 6.9.0-g1d4c6d784ef6 #37
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff800060dc>] dump_backtrace+0x1c/0x24
[<ffffffff8091ef6e>] show_stack+0x2c/0x38
[<ffffffff8092baf8>] dump_stack_lvl+0x5a/0x72
[<ffffffff8092bb24>] dump_stack+0x14/0x1c
[<ffffffff8003b7ac>] __might_resched+0x104/0x10e
[<ffffffff8003b7f4>] __might_sleep+0x3e/0x62
[<ffffffff8093276a>] down_write+0x20/0x72
[<ffffffff8000cf00>] __set_memory+0x82/0x2fa
[<ffffffff8000d324>] __kernel_map_pages+0x5a/0xd4
[<ffffffff80196cca>] __alloc_pages_bulk+0x3b2/0x43a
[<ffffffff8018ee82>] __vmalloc_node_range+0x196/0x6ba
[<ffffffff80011904>] copy_process+0x72c/0x17ec
[<ffffffff80012ab4>] kernel_clone+0x60/0x2fe
[<ffffffff80012f62>] kernel_thread+0x82/0xa0
[<ffffffff8003552c>] kthreadd+0x14a/0x1be
[<ffffffff809357de>] ret_from_fork+0xe/0x1c
Rewrite this function with apply_to_existing_page_range(). It is fine to
not have any locking, because __kernel_map_pages() works with pages being
allocated/deallocated and those pages are not changed by anyone else in the
meantime.
In the Linux kernel, the following vulnerability has been resolved:
drm/exynos: hdmi: report safe 640x480 mode as a fallback when no EDID found
When reading EDID fails and driver reports no modes available, the DRM
core adds an artificial 1024x786 mode to the connector. Unfortunately
some variants of the Exynos HDMI (like the one in Exynos4 SoCs) are not
able to drive such mode, so report a safe 640x480 mode instead of nothing
in case of the EDID reading failure.
This fixes the following issue observed on Trats2 board since commit
13d5b040363c ("drm/exynos: do not return negative values from .get_modes()"):
[drm] Exynos DRM: using 11c00000.fimd device for DMA mapping operations
exynos-drm exynos-drm: bound 11c00000.fimd (ops fimd_component_ops)
exynos-drm exynos-drm: bound 12c10000.mixer (ops mixer_component_ops)
exynos-dsi 11c80000.dsi: [drm:samsung_dsim_host_attach] Attached s6e8aa0 device (lanes:4 bpp:24 mode-flags:0x10b)
exynos-drm exynos-drm: bound 11c80000.dsi (ops exynos_dsi_component_ops)
exynos-drm exynos-drm: bound 12d00000.hdmi (ops hdmi_component_ops)
[drm] Initialized exynos 1.1.0 20180330 for exynos-drm on minor 1
exynos-hdmi 12d00000.hdmi: [drm:hdmiphy_enable.part.0] *ERROR* PLL could not reach steady state
panel-samsung-s6e8aa0 11c80000.dsi.0: ID: 0xa2, 0x20, 0x8c
exynos-mixer 12c10000.mixer: timeout waiting for VSYNC
------------[ cut here ]------------
WARNING: CPU: 1 PID: 11 at drivers/gpu/drm/drm_atomic_helper.c:1682 drm_atomic_helper_wait_for_vblanks.part.0+0x2b0/0x2b8
[CRTC:70:crtc-1] vblank wait timed out
Modules linked in:
CPU: 1 PID: 11 Comm: kworker/u16:0 Not tainted 6.9.0-rc5-next-20240424 #14913
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events_unbound deferred_probe_work_func
Call trace:
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x68/0x88
dump_stack_lvl from __warn+0x7c/0x1c4
__warn from warn_slowpath_fmt+0x11c/0x1a8
warn_slowpath_fmt from drm_atomic_helper_wait_for_vblanks.part.0+0x2b0/0x2b8
drm_atomic_helper_wait_for_vblanks.part.0 from drm_atomic_helper_commit_tail_rpm+0x7c/0x8c
drm_atomic_helper_commit_tail_rpm from commit_tail+0x9c/0x184
commit_tail from drm_atomic_helper_commit+0x168/0x190
drm_atomic_helper_commit from drm_atomic_commit+0xb4/0xe0
drm_atomic_commit from drm_client_modeset_commit_atomic+0x23c/0x27c
drm_client_modeset_commit_atomic from drm_client_modeset_commit_locked+0x60/0x1cc
drm_client_modeset_commit_locked from drm_client_modeset_commit+0x24/0x40
drm_client_modeset_commit from __drm_fb_helper_restore_fbdev_mode_unlocked+0x9c/0xc4
__drm_fb_helper_restore_fbdev_mode_unlocked from drm_fb_helper_set_par+0x2c/0x3c
drm_fb_helper_set_par from fbcon_init+0x3d8/0x550
fbcon_init from visual_init+0xc0/0x108
visual_init from do_bind_con_driver+0x1b8/0x3a4
do_bind_con_driver from do_take_over_console+0x140/0x1ec
do_take_over_console from do_fbcon_takeover+0x70/0xd0
do_fbcon_takeover from fbcon_fb_registered+0x19c/0x1ac
fbcon_fb_registered from register_framebuffer+0x190/0x21c
register_framebuffer from __drm_fb_helper_initial_config_and_unlock+0x350/0x574
__drm_fb_helper_initial_config_and_unlock from exynos_drm_fbdev_client_hotplug+0x6c/0xb0
exynos_drm_fbdev_client_hotplug from drm_client_register+0x58/0x94
drm_client_register from exynos_drm_bind+0x160/0x190
exynos_drm_bind from try_to_bring_up_aggregate_device+0x200/0x2d8
try_to_bring_up_aggregate_device from __component_add+0xb0/0x170
__component_add from mixer_probe+0x74/0xcc
mixer_probe from platform_probe+0x5c/0xb8
platform_probe from really_probe+0xe0/0x3d8
really_probe from __driver_probe_device+0x9c/0x1e4
__driver_probe_device from driver_probe_device+0x30/0xc0
driver_probe_device from __device_attach_driver+0xa8/0x120
__device_attach_driver from bus_for_each_drv+0x80/0xcc
bus_for_each_drv from __device_attach+0xac/0x1fc
__device_attach from bus_probe_device+0x8c/0x90
bus_probe_device from deferred_probe_work_func+0
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
memblock: make memblock_set_node() also warn about use of MAX_NUMNODES
On an (old) x86 system with SRAT just covering space above 4Gb:
ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0xfffffffff] hotplug
the commit referenced below leads to this NUMA configuration no longer
being refused by a CONFIG_NUMA=y kernel (previously
NUMA: nodes only cover 6144MB of your 8185MB e820 RAM. Not used.
No NUMA configuration found
Faking a node at [mem 0x0000000000000000-0x000000027fffffff]
was seen in the log directly after the message quoted above), because of
memblock_validate_numa_coverage() checking for NUMA_NO_NODE (only). This
in turn led to memblock_alloc_range_nid()'s warning about MAX_NUMNODES
triggering, followed by a NULL deref in memmap_init() when trying to
access node 64's (NODE_SHIFT=6) node data.
To compensate said change, make memblock_set_node() warn on and adjust
a passed in value of MAX_NUMNODES, just like various other functions
already do.
In the Linux kernel, the following vulnerability has been resolved:
parisc: Try to fix random segmentation faults in package builds
PA-RISC systems with PA8800 and PA8900 processors have had problems
with random segmentation faults for many years. Systems with earlier
processors are much more stable.
Systems with PA8800 and PA8900 processors have a large L2 cache which
needs per page flushing for decent performance when a large range is
flushed. The combined cache in these systems is also more sensitive to
non-equivalent aliases than the caches in earlier systems.
The majority of random segmentation faults that I have looked at
appear to be memory corruption in memory allocated using mmap and
malloc.
My first attempt at fixing the random faults didn't work. On
reviewing the cache code, I realized that there were two issues
which the existing code didn't handle correctly. Both relate
to cache move-in. Another issue is that the present bit in PTEs
is racy.
1) PA-RISC caches have a mind of their own and they can speculatively
load data and instructions for a page as long as there is a entry in
the TLB for the page which allows move-in. TLBs are local to each
CPU. Thus, the TLB entry for a page must be purged before flushing
the page. This is particularly important on SMP systems.
In some of the flush routines, the flush routine would be called
and then the TLB entry would be purged. This was because the flush
routine needed the TLB entry to do the flush.
2) My initial approach to trying the fix the random faults was to
try and use flush_cache_page_if_present for all flush operations.
This actually made things worse and led to a couple of hardware
lockups. It finally dawned on me that some lines weren't being
flushed because the pte check code was racy. This resulted in
random inequivalent mappings to physical pages.
The __flush_cache_page tmpalias flush sets up its own TLB entry
and it doesn't need the existing TLB entry. As long as we can find
the pte pointer for the vm page, we can get the pfn and physical
address of the page. We can also purge the TLB entry for the page
before doing the flush. Further, __flush_cache_page uses a special
TLB entry that inhibits cache move-in.
When switching page mappings, we need to ensure that lines are
removed from the cache. It is not sufficient to just flush the
lines to memory as they may come back.
This made it clear that we needed to implement all the required
flush operations using tmpalias routines. This includes flushes
for user and kernel pages.
After modifying the code to use tmpalias flushes, it became clear
that the random segmentation faults were not fully resolved. The
frequency of faults was worse on systems with a 64 MB L2 (PA8900)
and systems with more CPUs (rp4440).
The warning that I added to flush_cache_page_if_present to detect
pages that couldn't be flushed triggered frequently on some systems.
Helge and I looked at the pages that couldn't be flushed and found
that the PTE was either cleared or for a swap page. Ignoring pages
that were swapped out seemed okay but pages with cleared PTEs seemed
problematic.
I looked at routines related to pte_clear and noticed ptep_clear_flush.
The default implementation just flushes the TLB entry. However, it was
obvious that on parisc we need to flush the cache page as well. If
we don't flush the cache page, stale lines will be left in the cache
and cause random corruption. Once a PTE is cleared, there is no way
to find the physical address associated with the PTE and flush the
associated page at a later time.
I implemented an updated change with a parisc specific version of
ptep_clear_flush. It fixed the random data corruption on Helge's rp4440
and rp3440, as well as on my c8000.
At this point, I realized that I could restore the code where we only
flush in flush_cache_page_if_present if the page has been accessed.
However, for this, we also need to flush the cache when the accessed
bit is cleared in
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Adjust logging of firmware messages in case of released token in __hwrm_send()
In case of token is released due to token->state == BNXT_HWRM_DEFERRED,
released token (set to NULL) is used in log messages. This issue is
expected to be prevented by HWRM_ERR_CODE_PF_UNAVAILABLE error code. But
this error code is returned by recent firmware. So some firmware may not
return it. This may lead to NULL pointer dereference.
Adjust this issue by adding token pointer check.
Found by Linux Verification Center (linuxtesting.org) with SVACE.