| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| The libtiff-4.0.3-35.amzn2.0.1 package for LibTIFF on Amazon Linux 2 allows attackers to cause a denial of service (application crash), a different vulnerability than CVE-2022-0562. When processing a malicious TIFF file, an invalid range may be passed as an argument to the memset() function within TIFFFetchStripThing() in tif_dirread.c. This will cause TIFFFetchStripThing() to segfault after use of an uninitialized resource. |
| In the Linux kernel, the following vulnerability has been resolved:
leds: an30259a: Use devm_mutex_init() for mutex initialization
In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses mutex which was destroyed already
in module's remove() so use devm API instead. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: mediatek: Check num_codecs is not zero to avoid panic during probe
Following commit 13f58267cda3 ("ASoC: soc.h: don't create dummy
Component via COMP_DUMMY()"), COMP_DUMMY() became an array with zero
length, and only gets populated with the dummy struct after the card is
registered. Since the sound card driver's probe happens before the card
registration, accessing any of the members of a dummy component during
probe will result in undefined behavior.
This can be observed in the mt8188 and mt8195 machine sound drivers. By
omitting a dai link subnode in the sound card's node in the Devicetree,
the default uninitialized dummy codec is used, and when its dai_name
pointer gets passed to strcmp() it results in a null pointer dereference
and a kernel panic.
In addition to that, set_card_codec_info() in the generic helpers file,
mtk-soundcard-driver.c, will populate a dai link with a dummy codec when
a dai link node is present in DT but with no codec property.
The result is that at probe time, a dummy codec can either be
uninitialized with num_codecs = 0, or be an initialized dummy codec,
with num_codecs = 1 and dai_name = "snd-soc-dummy-dai". In order to
accommodate for both situations, check that num_codecs is not zero
before accessing the codecs' fields but still check for the codec's dai
name against "snd-soc-dummy-dai" as needed.
While at it, also drop the check that dai_name is not null in the mt8192
driver, introduced in commit 4d4e1b6319e5 ("ASoC: mediatek: mt8192:
Check existence of dai_name before dereferencing"), as it is actually
redundant given the preceding num_codecs != 0 check. |
| In the Linux kernel, the following vulnerability has been resolved:
net: txgbe: initialize num_q_vectors for MSI/INTx interrupts
When using MSI/INTx interrupts, wx->num_q_vectors is uninitialized.
Thus there will be kernel panic in wx_alloc_q_vectors() to allocate
queue vectors. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super()
In the following concurrency we will access the uninitialized rs->lock:
ext4_fill_super
ext4_register_sysfs
// sysfs registered msg_ratelimit_interval_ms
// Other processes modify rs->interval to
// non-zero via msg_ratelimit_interval_ms
ext4_orphan_cleanup
ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
__ext4_msg
___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state)
if (!rs->interval) // do nothing if interval is 0
return 1;
raw_spin_trylock_irqsave(&rs->lock, flags)
raw_spin_trylock(lock)
_raw_spin_trylock
__raw_spin_trylock
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_)
lock_acquire
__lock_acquire
register_lock_class
assign_lock_key
dump_stack();
ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
raw_spin_lock_init(&rs->lock);
// init rs->lock here
and get the following dump_stack:
=========================================================
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504
[...]
Call Trace:
dump_stack_lvl+0xc5/0x170
dump_stack+0x18/0x30
register_lock_class+0x740/0x7c0
__lock_acquire+0x69/0x13a0
lock_acquire+0x120/0x450
_raw_spin_trylock+0x98/0xd0
___ratelimit+0xf6/0x220
__ext4_msg+0x7f/0x160 [ext4]
ext4_orphan_cleanup+0x665/0x740 [ext4]
__ext4_fill_super+0x21ea/0x2b10 [ext4]
ext4_fill_super+0x14d/0x360 [ext4]
[...]
=========================================================
Normally interval is 0 until s_msg_ratelimit_state is initialized, so
___ratelimit() does nothing. But registering sysfs precedes initializing
rs->lock, so it is possible to change rs->interval to a non-zero value
via the msg_ratelimit_interval_ms interface of sysfs while rs->lock is
uninitialized, and then a call to ext4_msg triggers the problem by
accessing an uninitialized rs->lock. Therefore register sysfs after all
initializations are complete to avoid such problems. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: Fix KASAN error in LAG NETDEV_UNREGISTER handler
Currently, the same handler is called for both a NETDEV_BONDING_INFO
LAG unlink notification as for a NETDEV_UNREGISTER call. This is
causing a problem though, since the netdev_notifier_info passed has
a different structure depending on which event is passed. The problem
manifests as a call trace from a BUG: KASAN stack-out-of-bounds error.
Fix this by creating a handler specific to NETDEV_UNREGISTER that only
is passed valid elements in the netdev_notifier_info struct for the
NETDEV_UNREGISTER event.
Also included is the removal of an unbalanced dev_put on the peer_netdev
and related braces. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/a4xx: fix error handling in a4xx_gpu_init()
This code returns 1 on error instead of a negative error. It leads to
an Oops in the caller. A second problem is that the check for
"if (ret != -ENODATA)" cannot be true because "ret" is set to 1. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value
Currently, when the rule related to IDLETIMER is added, idletimer_tg timer
structure is initialized by kmalloc on executing idletimer_tg_create
function. However, in this process timer->timer_type is not defined to
a specific value. Thus, timer->timer_type has garbage value and it occurs
kernel panic. So, this commit fixes the panic by initializing
timer->timer_type using kzalloc instead of kmalloc.
Test commands:
# iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test
$ cat /sys/class/xt_idletimer/timers/test
Killed
Splat looks like:
BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70
Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917
CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
dump_stack_lvl+0x6e/0x9c
kasan_report.cold+0x112/0x117
? alarm_expires_remaining+0x49/0x70
__asan_load8+0x86/0xb0
alarm_expires_remaining+0x49/0x70
idletimer_tg_show+0xe5/0x19b [xt_IDLETIMER 11219304af9316a21bee5ba9d58f76a6b9bccc6d]
dev_attr_show+0x3c/0x60
sysfs_kf_seq_show+0x11d/0x1f0
? device_remove_bin_file+0x20/0x20
kernfs_seq_show+0xa4/0xb0
seq_read_iter+0x29c/0x750
kernfs_fop_read_iter+0x25a/0x2c0
? __fsnotify_parent+0x3d1/0x570
? iov_iter_init+0x70/0x90
new_sync_read+0x2a7/0x3d0
? __x64_sys_llseek+0x230/0x230
? rw_verify_area+0x81/0x150
vfs_read+0x17b/0x240
ksys_read+0xd9/0x180
? vfs_write+0x460/0x460
? do_syscall_64+0x16/0xc0
? lockdep_hardirqs_on+0x79/0x120
__x64_sys_read+0x43/0x50
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0cdc819142
Code: c0 e9 c2 fe ff ff 50 48 8d 3d 3a ca 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
RSP: 002b:00007fff28eee5b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f0cdc819142
RDX: 0000000000020000 RSI: 00007f0cdc032000 RDI: 0000000000000003
RBP: 00007f0cdc032000 R08: 00007f0cdc031010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 00005607e9ee31f0
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 |
| In the Linux kernel, the following vulnerability has been resolved:
llc: verify mac len before reading mac header
LLC reads the mac header with eth_hdr without verifying that the skb
has an Ethernet header.
Syzbot was able to enter llc_rcv on a tun device. Tun can insert
packets without mac len and with user configurable skb->protocol
(passing a tun_pi header when not configuring IFF_NO_PI).
BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218
__netif_receive_skb_one_core net/core/dev.c:5523 [inline]
__netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637
netif_receive_skb_internal net/core/dev.c:5723 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5782
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002
Add a mac_len test before all three eth_hdr(skb) calls under net/llc.
There are further uses in include/net/llc_pdu.h. All these are
protected by a test skb->protocol == ETH_P_802_2. Which does not
protect against this tun scenario.
But the mac_len test added in this patch in llc_fixup_skb will
indirectly protect those too. That is called from llc_rcv before any
other LLC code.
It is tempting to just add a blanket mac_len check in llc_rcv, but
not sure whether that could break valid LLC paths that do not assume
an Ethernet header. 802.2 LLC may be used on top of non-802.3
protocols in principle. The below referenced commit shows that used
to, on top of Token Ring.
At least one of the three eth_hdr uses goes back to before the start
of git history. But the one that syzbot exercises is introduced in
this commit. That commit is old enough (2008), that effectively all
stable kernels should receive this. |
| In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix freeing of uninitialized misc IRQ vector
When VSI set up failed in i40e_probe() as part of PF switch set up
driver was trying to free misc IRQ vectors in
i40e_clear_interrupt_scheme and produced a kernel Oops:
Trying to free already-free IRQ 266
WARNING: CPU: 0 PID: 5 at kernel/irq/manage.c:1731 __free_irq+0x9a/0x300
Workqueue: events work_for_cpu_fn
RIP: 0010:__free_irq+0x9a/0x300
Call Trace:
? synchronize_irq+0x3a/0xa0
free_irq+0x2e/0x60
i40e_clear_interrupt_scheme+0x53/0x190 [i40e]
i40e_probe.part.108+0x134b/0x1a40 [i40e]
? kmem_cache_alloc+0x158/0x1c0
? acpi_ut_update_ref_count.part.1+0x8e/0x345
? acpi_ut_update_object_reference+0x15e/0x1e2
? strstr+0x21/0x70
? irq_get_irq_data+0xa/0x20
? mp_check_pin_attr+0x13/0xc0
? irq_get_irq_data+0xa/0x20
? mp_map_pin_to_irq+0xd3/0x2f0
? acpi_register_gsi_ioapic+0x93/0x170
? pci_conf1_read+0xa4/0x100
? pci_bus_read_config_word+0x49/0x70
? do_pci_enable_device+0xcc/0x100
local_pci_probe+0x41/0x90
work_for_cpu_fn+0x16/0x20
process_one_work+0x1a7/0x360
worker_thread+0x1cf/0x390
? create_worker+0x1a0/0x1a0
kthread+0x112/0x130
? kthread_flush_work_fn+0x10/0x10
ret_from_fork+0x1f/0x40
The problem is that at that point misc IRQ vectors
were not allocated yet and we get a call trace
that driver is trying to free already free IRQ vectors.
Add a check in i40e_clear_interrupt_scheme for __I40E_MISC_IRQ_REQUESTED
PF state before calling i40e_free_misc_vector. This state is set only if
misc IRQ vectors were properly initialized. |
| In the Linux kernel, the following vulnerability has been resolved:
cxl/region: Do not try to cleanup after cxl_region_setup_targets() fails
Commit 5e42bcbc3fef ("cxl/region: decrement ->nr_targets on error in
cxl_region_attach()") tried to avoid 'eiw' initialization errors when
->nr_targets exceeded 16, by just decrementing ->nr_targets when
cxl_region_setup_targets() failed.
Commit 86987c766276 ("cxl/region: Cleanup target list on attach error")
extended that cleanup to also clear cxled->pos and p->targets[pos]. The
initialization error was incidentally fixed separately by:
Commit 8d4285425714 ("cxl/region: Fix port setup uninitialized variable
warnings") which was merged a few days after 5e42bcbc3fef.
But now the original cleanup when cxl_region_setup_targets() fails
prevents endpoint and switch decoder resources from being reused:
1) the cleanup does not set the decoder's region to NULL, which results
in future dpa_size_store() calls returning -EBUSY
2) the decoder is not properly freed, which results in future commit
errors associated with the upstream switch
Now that the initialization errors were fixed separately, the proper
cleanup for this case is to just return immediately. Then the resources
associated with this target get cleanup up as normal when the failed
region is deleted.
The ->nr_targets decrement in the error case also helped prevent
a p->targets[] array overflow, so add a new check to prevent against
that overflow.
Tested by trying to create an invalid region for a 2 switch * 2 endpoint
topology, and then following up with creating a valid region. |
| In the Linux kernel, the following vulnerability has been resolved:
net/usb: kalmia: Don't pass act_len in usb_bulk_msg error path
syzbot reported that act_len in kalmia_send_init_packet() is
uninitialized when passing it to the first usb_bulk_msg error path. Jiri
Pirko noted that it's pointless to pass it in the error path, and that
the value that would be printed in the second error path would be the
value of act_len from the first call to usb_bulk_msg.[1]
With this in mind, let's just not pass act_len to the usb_bulk_msg error
paths.
1: https://lore.kernel.org/lkml/Y9pY61y1nwTuzMOa@nanopsycho/ |
| In the Linux kernel, the following vulnerability has been resolved:
ath11k: pci: fix crash on suspend if board file is not found
Mario reported that the kernel was crashing on suspend if ath11k was not able
to find a board file:
[ 473.693286] PM: Suspending system (s2idle)
[ 473.693291] printk: Suspending console(s) (use no_console_suspend to debug)
[ 474.407787] BUG: unable to handle page fault for address: 0000000000002070
[ 474.407791] #PF: supervisor read access in kernel mode
[ 474.407794] #PF: error_code(0x0000) - not-present page
[ 474.407798] PGD 0 P4D 0
[ 474.407801] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 474.407805] CPU: 2 PID: 2350 Comm: kworker/u32:14 Tainted: G W 5.16.0 #248
[...]
[ 474.407868] Call Trace:
[ 474.407870] <TASK>
[ 474.407874] ? _raw_spin_lock_irqsave+0x2a/0x60
[ 474.407882] ? lock_timer_base+0x72/0xa0
[ 474.407889] ? _raw_spin_unlock_irqrestore+0x29/0x3d
[ 474.407892] ? try_to_del_timer_sync+0x54/0x80
[ 474.407896] ath11k_dp_rx_pktlog_stop+0x49/0xc0 [ath11k]
[ 474.407912] ath11k_core_suspend+0x34/0x130 [ath11k]
[ 474.407923] ath11k_pci_pm_suspend+0x1b/0x50 [ath11k_pci]
[ 474.407928] pci_pm_suspend+0x7e/0x170
[ 474.407935] ? pci_pm_freeze+0xc0/0xc0
[ 474.407939] dpm_run_callback+0x4e/0x150
[ 474.407947] __device_suspend+0x148/0x4c0
[ 474.407951] async_suspend+0x20/0x90
dmesg-efi-164255130401001:
Oops#1 Part1
[ 474.407955] async_run_entry_fn+0x33/0x120
[ 474.407959] process_one_work+0x220/0x3f0
[ 474.407966] worker_thread+0x4a/0x3d0
[ 474.407971] kthread+0x17a/0x1a0
[ 474.407975] ? process_one_work+0x3f0/0x3f0
[ 474.407979] ? set_kthread_struct+0x40/0x40
[ 474.407983] ret_from_fork+0x22/0x30
[ 474.407991] </TASK>
The issue here is that board file loading happens after ath11k_pci_probe()
succesfully returns (ath11k initialisation happends asynchronously) and the
suspend handler is still enabled, of course failing as ath11k is not properly
initialised. Fix this by checking ATH11K_FLAG_QMI_FAIL during both suspend and
resume.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03003-QCAHSPSWPL_V1_V2_SILICONZ_LITE-2 |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btmtksdio: Fix kernel oops in btmtksdio_interrupt
Fix the following kernel oops in btmtksdio_interrrupt
[ 14.339134] btmtksdio_interrupt+0x28/0x54
[ 14.339139] process_sdio_pending_irqs+0x68/0x1a0
[ 14.339144] sdio_irq_work+0x40/0x70
[ 14.339154] process_one_work+0x184/0x39c
[ 14.339160] worker_thread+0x228/0x3e8
[ 14.339168] kthread+0x148/0x3ac
[ 14.339176] ret_from_fork+0x10/0x30
That happened because hdev->power_on is already called before
sdio_set_drvdata which btmtksdio_interrupt handler relies on is not
properly set up.
The details are shown as the below: hci_register_dev would run
queue_work(hdev->req_workqueue, &hdev->power_on) as WQ_HIGHPRI
workqueue_struct to complete the power-on sequeunce and thus hci_power_on
may run before sdio_set_drvdata is done in btmtksdio_probe.
The hci_dev_do_open in hci_power_on would initialize the device and enable
the interrupt and thus it is possible that btmtksdio_interrupt is being
called right before sdio_set_drvdata is filled out.
When btmtksdio_interrupt is being called and sdio_set_drvdata is not filled
, the kernel oops is going to happen because btmtksdio_interrupt access an
uninitialized pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: firewire-lib: fix uninitialized flag for AV/C deferred transaction
AV/C deferred transaction was supported at a commit 00a7bb81c20f ("ALSA:
firewire-lib: Add support for deferred transaction") while 'deferrable'
flag can be uninitialized for non-control/notify AV/C transactions.
UBSAN reports it:
kernel: ================================================================================
kernel: UBSAN: invalid-load in /build/linux-aa0B4d/linux-5.15.0/sound/firewire/fcp.c:363:9
kernel: load of value 158 is not a valid value for type '_Bool'
kernel: CPU: 3 PID: 182227 Comm: irq/35-firewire Tainted: P OE 5.15.0-18-generic #18-Ubuntu
kernel: Hardware name: Gigabyte Technology Co., Ltd. AX370-Gaming 5/AX370-Gaming 5, BIOS F42b 08/01/2019
kernel: Call Trace:
kernel: <IRQ>
kernel: show_stack+0x52/0x58
kernel: dump_stack_lvl+0x4a/0x5f
kernel: dump_stack+0x10/0x12
kernel: ubsan_epilogue+0x9/0x45
kernel: __ubsan_handle_load_invalid_value.cold+0x44/0x49
kernel: fcp_response.part.0.cold+0x1a/0x2b [snd_firewire_lib]
kernel: fcp_response+0x28/0x30 [snd_firewire_lib]
kernel: fw_core_handle_request+0x230/0x3d0 [firewire_core]
kernel: handle_ar_packet+0x1d9/0x200 [firewire_ohci]
kernel: ? handle_ar_packet+0x1d9/0x200 [firewire_ohci]
kernel: ? transmit_complete_callback+0x9f/0x120 [firewire_core]
kernel: ar_context_tasklet+0xa8/0x2e0 [firewire_ohci]
kernel: tasklet_action_common.constprop.0+0xea/0xf0
kernel: tasklet_action+0x22/0x30
kernel: __do_softirq+0xd9/0x2e3
kernel: ? irq_finalize_oneshot.part.0+0xf0/0xf0
kernel: do_softirq+0x75/0xa0
kernel: </IRQ>
kernel: <TASK>
kernel: __local_bh_enable_ip+0x50/0x60
kernel: irq_forced_thread_fn+0x7e/0x90
kernel: irq_thread+0xba/0x190
kernel: ? irq_thread_fn+0x60/0x60
kernel: kthread+0x11e/0x140
kernel: ? irq_thread_check_affinity+0xf0/0xf0
kernel: ? set_kthread_struct+0x50/0x50
kernel: ret_from_fork+0x22/0x30
kernel: </TASK>
kernel: ================================================================================
This commit fixes the bug. The bug has no disadvantage for the non-
control/notify AV/C transactions since the flag has an effect for AV/C
response with INTERIM (0x0f) status which is not used for the transactions
in AV/C general specification. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix crash when mount with quota enabled
There is a reported crash when mounting ocfs2 with quota enabled.
RIP: 0010:ocfs2_qinfo_lock_res_init+0x44/0x50 [ocfs2]
Call Trace:
ocfs2_local_read_info+0xb9/0x6f0 [ocfs2]
dquot_load_quota_sb+0x216/0x470
dquot_load_quota_inode+0x85/0x100
ocfs2_enable_quotas+0xa0/0x1c0 [ocfs2]
ocfs2_fill_super.cold+0xc8/0x1bf [ocfs2]
mount_bdev+0x185/0x1b0
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
path_mount+0x465/0xac0
__x64_sys_mount+0x103/0x140
It is caused by when initializing dqi_gqlock, the corresponding dqi_type
and dqi_sb are not properly initialized.
This issue is introduced by commit 6c85c2c72819, which wants to avoid
accessing uninitialized variables in error cases. So make global quota
info properly initialized. |
| In the Linux kernel, the following vulnerability has been resolved:
net: mdio: unexport __init-annotated mdio_bus_init()
EXPORT_SYMBOL and __init is a bad combination because the .init.text
section is freed up after the initialization. Hence, modules cannot
use symbols annotated __init. The access to a freed symbol may end up
with kernel panic.
modpost used to detect it, but it has been broken for a decade.
Recently, I fixed modpost so it started to warn it again, then this
showed up in linux-next builds.
There are two ways to fix it:
- Remove __init
- Remove EXPORT_SYMBOL
I chose the latter for this case because the only in-tree call-site,
drivers/net/phy/phy_device.c is never compiled as modular.
(CONFIG_PHYLIB is boolean) |
| In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix free of uninitialized nfs4_label on referral lookup.
Send along the already-allocated fattr along with nfs4_fs_locations, and
drop the memcpy of fattr. We end up growing two more allocations, but this
fixes up a crash as:
PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls"
#0 [ffffc90000857920] panic at ffffffff81b9bfde
#1 [ffffc900008579c0] do_trap at ffffffff81023a9b
#2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
#3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
#4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
#5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
#6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
#7 [ffffc90000857c60] walk_component at ffffffff813a86c4
#8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
#9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b |
| MongoDB Server may access non-initialized region of memory leading to unexpected behaviour when zero arguments are called in internal aggregation stage. This issue affected MongoDB Server v6.0 version 6.0.3. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/scs: Reset task stack state in bringup_cpu()
To hot unplug a CPU, the idle task on that CPU calls a few layers of C
code before finally leaving the kernel. When KASAN is in use, poisoned
shadow is left around for each of the active stack frames, and when
shadow call stacks are in use. When shadow call stacks (SCS) are in use
the task's saved SCS SP is left pointing at an arbitrary point within
the task's shadow call stack.
When a CPU is offlined than onlined back into the kernel, this stale
state can adversely affect execution. Stale KASAN shadow can alias new
stackframes and result in bogus KASAN warnings. A stale SCS SP is
effectively a memory leak, and prevents a portion of the shadow call
stack being used. Across a number of hotplug cycles the idle task's
entire shadow call stack can become unusable.
We previously fixed the KASAN issue in commit:
e1b77c92981a5222 ("sched/kasan: remove stale KASAN poison after hotplug")
... by removing any stale KASAN stack poison immediately prior to
onlining a CPU.
Subsequently in commit:
f1a0a376ca0c4ef1 ("sched/core: Initialize the idle task with preemption disabled")
... the refactoring left the KASAN and SCS cleanup in one-time idle
thread initialization code rather than something invoked prior to each
CPU being onlined, breaking both as above.
We fixed SCS (but not KASAN) in commit:
63acd42c0d4942f7 ("sched/scs: Reset the shadow stack when idle_task_exit")
... but as this runs in the context of the idle task being offlined it's
potentially fragile.
To fix these consistently and more robustly, reset the SCS SP and KASAN
shadow of a CPU's idle task immediately before we online that CPU in
bringup_cpu(). This ensures the idle task always has a consistent state
when it is running, and removes the need to so so when exiting an idle
task.
Whenever any thread is created, dup_task_struct() will give the task a
stack which is free of KASAN shadow, and initialize the task's SCS SP,
so there's no need to specially initialize either for idle thread within
init_idle(), as this was only necessary to handle hotplug cycles.
I've tested this on arm64 with:
* gcc 11.1.0, defconfig +KASAN_INLINE, KASAN_STACK
* clang 12.0.0, defconfig +KASAN_INLINE, KASAN_STACK, SHADOW_CALL_STACK
... offlining and onlining CPUS with:
| while true; do
| for C in /sys/devices/system/cpu/cpu*/online; do
| echo 0 > $C;
| echo 1 > $C;
| done
| done |
