| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| When the assert() function in the GNU C Library versions 2.13 to 2.40 fails, it does not allocate enough space for the assertion failure message string and size information, which may lead to a buffer overflow if the message string size aligns to page size. |
| In the Linux kernel, the following vulnerability has been resolved:
tls: separate no-async decryption request handling from async
If we're not doing async, the handling is much simpler. There's no
reference counting, we just need to wait for the completion to wake us
up and return its result.
We should preferably also use a separate crypto_wait. I'm not seeing a
UAF as I did in the past, I think aec7961916f3 ("tls: fix race between
async notify and socket close") took care of it.
This will make the next fix easier. |
| In the Linux kernel, the following vulnerability has been resolved:
tomoyo: don't emit warning in tomoyo_write_control()
syzbot is reporting too large allocation warning at tomoyo_write_control(),
for one can write a very very long line without new line character. To fix
this warning, I use __GFP_NOWARN rather than checking for KMALLOC_MAX_SIZE,
for practically a valid line should be always shorter than 32KB where the
"too small to fail" memory-allocation rule applies.
One might try to write a valid line that is longer than 32KB, but such
request will likely fail with -ENOMEM. Therefore, I feel that separately
returning -EINVAL when a line is longer than KMALLOC_MAX_SIZE is redundant.
There is no need to distinguish over-32KB and over-KMALLOC_MAX_SIZE. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtlwifi: remove unused check_buddy_priv
Commit 2461c7d60f9f ("rtlwifi: Update header file") introduced a global
list of private data structures.
Later on, commit 26634c4b1868 ("rtlwifi Modify existing bits to match
vendor version 2013.02.07") started adding the private data to that list at
probe time and added a hook, check_buddy_priv to find the private data from
a similar device.
However, that function was never used.
Besides, though there is a lock for that list, it is never used. And when
the probe fails, the private data is never removed from the list. This
would cause a second probe to access freed memory.
Remove the unused hook, structures and members, which will prevent the
potential race condition on the list and its corruption during a second
probe when probe fails. |
| In the Linux kernel, the following vulnerability has been resolved:
team: prevent adding a device which is already a team device lower
Prevent adding a device which is already a team device lower,
e.g. adding veth0 if vlan1 was already added and veth0 is a lower of
vlan1.
This is not useful in practice and can lead to recursive locking:
$ ip link add veth0 type veth peer name veth1
$ ip link set veth0 up
$ ip link set veth1 up
$ ip link add link veth0 name veth0.1 type vlan protocol 802.1Q id 1
$ ip link add team0 type team
$ ip link set veth0.1 down
$ ip link set veth0.1 master team0
team0: Port device veth0.1 added
$ ip link set veth0 down
$ ip link set veth0 master team0
============================================
WARNING: possible recursive locking detected
6.13.0-rc2-virtme-00441-ga14a429069bb #46 Not tainted
--------------------------------------------
ip/7684 is trying to acquire lock:
ffff888016848e00 (team->team_lock_key){+.+.}-{4:4}, at: team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
but task is already holding lock:
ffff888016848e00 (team->team_lock_key){+.+.}-{4:4}, at: team_add_slave (drivers/net/team/team_core.c:1147 drivers/net/team/team_core.c:1977)
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(team->team_lock_key);
lock(team->team_lock_key);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by ip/7684:
stack backtrace:
CPU: 3 UID: 0 PID: 7684 Comm: ip Not tainted 6.13.0-rc2-virtme-00441-ga14a429069bb #46
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:122)
print_deadlock_bug.cold (kernel/locking/lockdep.c:3040)
__lock_acquire (kernel/locking/lockdep.c:3893 kernel/locking/lockdep.c:5226)
? netlink_broadcast_filtered (net/netlink/af_netlink.c:1548)
lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 2))
? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
? lock_acquire (kernel/locking/lockdep.c:5822)
? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
__mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:735)
? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
? fib_sync_up (net/ipv4/fib_semantics.c:2167)
? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973)
notifier_call_chain (kernel/notifier.c:85)
call_netdevice_notifiers_info (net/core/dev.c:1996)
__dev_notify_flags (net/core/dev.c:8993)
? __dev_change_flags (net/core/dev.c:8975)
dev_change_flags (net/core/dev.c:9027)
vlan_device_event (net/8021q/vlan.c:85 net/8021q/vlan.c:470)
? br_device_event (net/bridge/br.c:143)
notifier_call_chain (kernel/notifier.c:85)
call_netdevice_notifiers_info (net/core/dev.c:1996)
dev_open (net/core/dev.c:1519 net/core/dev.c:1505)
team_add_slave (drivers/net/team/team_core.c:1219 drivers/net/team/team_core.c:1977)
? __pfx_team_add_slave (drivers/net/team/team_core.c:1972)
do_set_master (net/core/rtnetlink.c:2917)
do_setlink.isra.0 (net/core/rtnetlink.c:3117) |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtlwifi: fix memory leaks and invalid access at probe error path
Deinitialize at reverse order when probe fails.
When init_sw_vars fails, rtl_deinit_core should not be called, specially
now that it destroys the rtl_wq workqueue.
And call rtl_pci_deinit and deinit_sw_vars, otherwise, memory will be
leaked.
Remove pci_set_drvdata call as it will already be cleaned up by the core
driver code and could lead to memory leaks too. cf. commit 8d450935ae7f
("wireless: rtlwifi: remove unnecessary pci_set_drvdata()") and
commit 3d86b93064c7 ("rtlwifi: Fix PCI probe error path orphaned memory"). |
| In the Linux kernel, the following vulnerability has been resolved:
ubifs: skip dumping tnc tree when zroot is null
Clearing slab cache will free all znode in memory and make
c->zroot.znode = NULL, then dumping tnc tree will access
c->zroot.znode which cause null pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
ipmi: ipmb: Add check devm_kasprintf() returned value
devm_kasprintf() can return a NULL pointer on failure but this
returned value is not checked. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: multitouch: Add NULL check in mt_input_configured
devm_kasprintf() can return a NULL pointer on failure,but this
returned value in mt_input_configured() is not checked.
Add NULL check in mt_input_configured(), to handle kernel NULL
pointer dereference error. |
| In the Linux kernel, the following vulnerability has been resolved:
printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX
Shifting 1 << 31 on a 32-bit int causes signed integer overflow, which
leads to undefined behavior. To prevent this, cast 1 to u32 before
performing the shift, ensuring well-defined behavior.
This change explicitly avoids any potential overflow by ensuring that
the shift occurs on an unsigned 32-bit integer. |
| In the Linux kernel, the following vulnerability has been resolved:
safesetid: check size of policy writes
syzbot attempts to write a buffer with a large size to a sysfs entry
with writes handled by handle_policy_update(), triggering a warning
in kmalloc.
Check the size specified for write buffers before allocating.
[PM: subject tweak] |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmsmac: add gain range check to wlc_phy_iqcal_gainparams_nphy()
In 'wlc_phy_iqcal_gainparams_nphy()', add gain range check to WARN()
instead of possible out-of-bounds 'tbl_iqcal_gainparams_nphy' access.
Compile tested only.
Found by Linux Verification Center (linuxtesting.org) with SVACE. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: handle NULL sock pointer in l2cap_sock_alloc
A NULL sock pointer is passed into l2cap_sock_alloc() when it is called
from l2cap_sock_new_connection_cb() and the error handling paths should
also be aware of it.
Seemingly a more elegant solution would be to swap bt_sock_alloc() and
l2cap_chan_create() calls since they are not interdependent to that moment
but then l2cap_chan_create() adds the soon to be deallocated and still
dummy-initialized channel to the global list accessible by many L2CAP
paths. The channel would be removed from the list in short period of time
but be a bit more straight-forward here and just check for NULL instead of
changing the order of function calls.
Found by Linux Verification Center (linuxtesting.org) with SVACE static
analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
tpm: Change to kvalloc() in eventlog/acpi.c
The following failure was reported on HPE ProLiant D320:
[ 10.693310][ T1] tpm_tis STM0925:00: 2.0 TPM (device-id 0x3, rev-id 0)
[ 10.848132][ T1] ------------[ cut here ]------------
[ 10.853559][ T1] WARNING: CPU: 59 PID: 1 at mm/page_alloc.c:4727 __alloc_pages_noprof+0x2ca/0x330
[ 10.862827][ T1] Modules linked in:
[ 10.866671][ T1] CPU: 59 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-lp155.2.g52785e2-default #1 openSUSE Tumbleweed (unreleased) 588cd98293a7c9eba9013378d807364c088c9375
[ 10.882741][ T1] Hardware name: HPE ProLiant DL320 Gen12/ProLiant DL320 Gen12, BIOS 1.20 10/28/2024
[ 10.892170][ T1] RIP: 0010:__alloc_pages_noprof+0x2ca/0x330
[ 10.898103][ T1] Code: 24 08 e9 4a fe ff ff e8 34 36 fa ff e9 88 fe ff ff 83 fe 0a 0f 86 b3 fd ff ff 80 3d 01 e7 ce 01 00 75 09 c6 05 f8 e6 ce 01 01 <0f> 0b 45 31 ff e9 e5 fe ff ff f7 c2 00 00 08 00 75 42 89 d9 80 e1
[ 10.917750][ T1] RSP: 0000:ffffb7cf40077980 EFLAGS: 00010246
[ 10.923777][ T1] RAX: 0000000000000000 RBX: 0000000000040cc0 RCX: 0000000000000000
[ 10.931727][ T1] RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000040cc0
The above transcript shows that ACPI pointed a 16 MiB buffer for the log
events because RSI maps to the 'order' parameter of __alloc_pages_noprof().
Address the bug by moving from devm_kmalloc() to devm_add_action() and
kvmalloc() and devm_add_action(). |
| In the Linux kernel, the following vulnerability has been resolved:
net_sched: sch_sfq: don't allow 1 packet limit
The current implementation does not work correctly with a limit of
1. iproute2 actually checks for this and this patch adds the check in
kernel as well.
This fixes the following syzkaller reported crash:
UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:210:6
index 65535 is out of range for type 'struct sfq_head[128]'
CPU: 0 PID: 2569 Comm: syz-executor101 Not tainted 5.10.0-smp-DEV #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x125/0x19f lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:148 [inline]
__ubsan_handle_out_of_bounds+0xed/0x120 lib/ubsan.c:347
sfq_link net/sched/sch_sfq.c:210 [inline]
sfq_dec+0x528/0x600 net/sched/sch_sfq.c:238
sfq_dequeue+0x39b/0x9d0 net/sched/sch_sfq.c:500
sfq_reset+0x13/0x50 net/sched/sch_sfq.c:525
qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026
tbf_reset+0x3d/0x100 net/sched/sch_tbf.c:319
qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026
dev_reset_queue+0x8c/0x140 net/sched/sch_generic.c:1296
netdev_for_each_tx_queue include/linux/netdevice.h:2350 [inline]
dev_deactivate_many+0x6dc/0xc20 net/sched/sch_generic.c:1362
__dev_close_many+0x214/0x350 net/core/dev.c:1468
dev_close_many+0x207/0x510 net/core/dev.c:1506
unregister_netdevice_many+0x40f/0x16b0 net/core/dev.c:10738
unregister_netdevice_queue+0x2be/0x310 net/core/dev.c:10695
unregister_netdevice include/linux/netdevice.h:2893 [inline]
__tun_detach+0x6b6/0x1600 drivers/net/tun.c:689
tun_detach drivers/net/tun.c:705 [inline]
tun_chr_close+0x104/0x1b0 drivers/net/tun.c:3640
__fput+0x203/0x840 fs/file_table.c:280
task_work_run+0x129/0x1b0 kernel/task_work.c:185
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x5ce/0x2200 kernel/exit.c:931
do_group_exit+0x144/0x310 kernel/exit.c:1046
__do_sys_exit_group kernel/exit.c:1057 [inline]
__se_sys_exit_group kernel/exit.c:1055 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1055
do_syscall_64+0x6c/0xd0
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fe5e7b52479
Code: Unable to access opcode bytes at RIP 0x7fe5e7b5244f.
RSP: 002b:00007ffd3c800398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e7b52479
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007fe5e7bcd2d0 R08: ffffffffffffffb8 R09: 0000000000000014
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5e7bcd2d0
R13: 0000000000000000 R14: 00007fe5e7bcdd20 R15: 00007fe5e7b24270
The crash can be also be reproduced with the following (with a tc
recompiled to allow for sfq limits of 1):
tc qdisc add dev dummy0 handle 1: root tbf rate 1Kbit burst 100b lat 1s
../iproute2-6.9.0/tc/tc qdisc add dev dummy0 handle 2: parent 1:10 sfq limit 1
ifconfig dummy0 up
ping -I dummy0 -f -c2 -W0.1 8.8.8.8
sleep 1
Scenario that triggers the crash:
* the first packet is sent and queued in TBF and SFQ; qdisc qlen is 1
* TBF dequeues: it peeks from SFQ which moves the packet to the
gso_skb list and keeps qdisc qlen set to 1. TBF is out of tokens so
it schedules itself for later.
* the second packet is sent and TBF tries to queues it to SFQ. qdisc
qlen is now 2 and because the SFQ limit is 1 the packet is dropped
by SFQ. At this point qlen is 1, and all of the SFQ slots are empty,
however q->tail is not NULL.
At this point, assuming no more packets are queued, when sch_dequeue
runs again it will decrement the qlen for the current empty slot
causing an underflow and the subsequent out of bounds access. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: core: Fix assumption that Resolution Multipliers must be in Logical Collections
A report in 2019 by the syzbot fuzzer was found to be connected to two
errors in the HID core associated with Resolution Multipliers. One of
the errors was fixed by commit ea427a222d8b ("HID: core: Fix deadloop
in hid_apply_multiplier."), but the other has not been fixed.
This error arises because hid_apply_multipler() assumes that every
Resolution Multiplier control is contained in a Logical Collection,
i.e., there's no way the routine can ever set multiplier_collection to
NULL. This is in spite of the fact that the function starts with a
big comment saying:
* "The Resolution Multiplier control must be contained in the same
* Logical Collection as the control(s) to which it is to be applied.
...
* If no Logical Collection is
* defined, the Resolution Multiplier is associated with all
* controls in the report."
* HID Usage Table, v1.12, Section 4.3.1, p30
*
* Thus, search from the current collection upwards until we find a
* logical collection...
The comment and the code overlook the possibility that none of the
collections found may be a Logical Collection.
The fix is to set the multiplier_collection pointer to NULL if the
collection found isn't a Logical Collection. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Fix NULL pointer dereference on certain command aborts
If a command is queued to the final usable TRB of a ring segment, the
enqueue pointer is advanced to the subsequent link TRB and no further.
If the command is later aborted, when the abort completion is handled
the dequeue pointer is advanced to the first TRB of the next segment.
If no further commands are queued, xhci_handle_stopped_cmd_ring() sees
the ring pointers unequal and assumes that there is a pending command,
so it calls xhci_mod_cmd_timer() which crashes if cur_cmd was NULL.
Don't attempt timer setup if cur_cmd is NULL. The subsequent doorbell
ring likely is unnecessary too, but it's harmless. Leave it alone.
This is probably Bug 219532, but no confirmation has been received.
The issue has been independently reproduced and confirmed fixed using
a USB MCU programmed to NAK the Status stage of SET_ADDRESS forever.
Everything continued working normally after several prevented crashes. |
| In the Linux kernel, the following vulnerability has been resolved:
pps: Fix a use-after-free
On a board running ntpd and gpsd, I'm seeing a consistent use-after-free
in sys_exit() from gpsd when rebooting:
pps pps1: removed
------------[ cut here ]------------
kobject: '(null)' (00000000db4bec24): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 2 PID: 440 at lib/kobject.c:734 kobject_put+0x120/0x150
CPU: 2 UID: 299 PID: 440 Comm: gpsd Not tainted 6.11.0-rc6-00308-gb31c44928842 #1
Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kobject_put+0x120/0x150
lr : kobject_put+0x120/0x150
sp : ffffffc0803d3ae0
x29: ffffffc0803d3ae0 x28: ffffff8042dc9738 x27: 0000000000000001
x26: 0000000000000000 x25: ffffff8042dc9040 x24: ffffff8042dc9440
x23: ffffff80402a4620 x22: ffffff8042ef4bd0 x21: ffffff80405cb600
x20: 000000000008001b x19: ffffff8040b3b6e0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 696e6920746f6e20
x14: 7369203a29343263 x13: 205d303434542020 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
kobject_put+0x120/0x150
cdev_put+0x20/0x3c
__fput+0x2c4/0x2d8
____fput+0x1c/0x38
task_work_run+0x70/0xfc
do_exit+0x2a0/0x924
do_group_exit+0x34/0x90
get_signal+0x7fc/0x8c0
do_signal+0x128/0x13b4
do_notify_resume+0xdc/0x160
el0_svc+0xd4/0xf8
el0t_64_sync_handler+0x140/0x14c
el0t_64_sync+0x190/0x194
---[ end trace 0000000000000000 ]---
...followed by more symptoms of corruption, with similar stacks:
refcount_t: underflow; use-after-free.
kernel BUG at lib/list_debug.c:62!
Kernel panic - not syncing: Oops - BUG: Fatal exception
This happens because pps_device_destruct() frees the pps_device with the
embedded cdev immediately after calling cdev_del(), but, as the comment
above cdev_del() notes, fops for previously opened cdevs are still
callable even after cdev_del() returns. I think this bug has always
been there: I can't explain why it suddenly started happening every time
I reboot this particular board.
In commit d953e0e837e6 ("pps: Fix a use-after free bug when
unregistering a source."), George Spelvin suggested removing the
embedded cdev. That seems like the simplest way to fix this, so I've
implemented his suggestion, using __register_chrdev() with pps_idr
becoming the source of truth for which minor corresponds to which
device.
But now that pps_idr defines userspace visibility instead of cdev_add(),
we need to be sure the pps->dev refcount can't reach zero while
userspace can still find it again. So, the idr_remove() call moves to
pps_unregister_cdev(), and pps_idr now holds a reference to pps->dev.
pps_core: source serial1 got cdev (251:1)
<...>
pps pps1: removed
pps_core: unregistering pps1
pps_core: deallocating pps1 |
| In the Linux kernel, the following vulnerability has been resolved:
memcg: fix soft lockup in the OOM process
A soft lockup issue was found in the product with about 56,000 tasks were
in the OOM cgroup, it was traversing them when the soft lockup was
triggered.
watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066]
CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G
Hardware name: Huawei Cloud OpenStack Nova, BIOS
RIP: 0010:console_unlock+0x343/0x540
RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247
RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040
R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0
R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
vprintk_emit+0x193/0x280
printk+0x52/0x6e
dump_task+0x114/0x130
mem_cgroup_scan_tasks+0x76/0x100
dump_header+0x1fe/0x210
oom_kill_process+0xd1/0x100
out_of_memory+0x125/0x570
mem_cgroup_out_of_memory+0xb5/0xd0
try_charge+0x720/0x770
mem_cgroup_try_charge+0x86/0x180
mem_cgroup_try_charge_delay+0x1c/0x40
do_anonymous_page+0xb5/0x390
handle_mm_fault+0xc4/0x1f0
This is because thousands of processes are in the OOM cgroup, it takes a
long time to traverse all of them. As a result, this lead to soft lockup
in the OOM process.
To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks'
function per 1000 iterations. For global OOM, call
'touch_softlockup_watchdog' per 1000 iterations to avoid this issue. |
| In the Linux kernel, the following vulnerability has been resolved:
hrtimers: Handle CPU state correctly on hotplug
Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway
through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to
CPUHP_ONLINE:
Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set
to 1 throughout. However, during a CPU unplug operation, the tick and the
clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online
state, for instance CFS incorrectly assumes that the hrtick is already
active, and the chance of the clockevent device to transition to oneshot
mode is also lost forever for the CPU, unless it goes back to a lower state
than CPUHP_HRTIMERS_PREPARE once.
This round-trip reveals another issue; cpu_base.online is not set to 1
after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer().
Aside of that, the bulk of the per CPU state is not reset either, which
means there are dangling pointers in the worst case.
Address this by adding a corresponding startup() callback, which resets the
stale per CPU state and sets the online flag.
[ tglx: Make the new callback unconditionally available, remove the online
modification in the prepare() callback and clear the remaining
state in the starting callback instead of the prepare callback ] |
