| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
iavf: get rid of the crit lock
Get rid of the crit lock.
That frees us from the error prone logic of try_locks.
Thanks to netdev_lock() by Jakub it is now easy, and in most cases we were
protected by it already - replace crit lock by netdev lock when it was not
the case.
Lockdep reports that we should cancel the work under crit_lock [splat1],
and that was the scheme we have mostly followed since [1] by Slawomir.
But when that is done we still got into deadlocks [splat2]. So instead
we should look at the bigger problem, namely "weird locking/scheduling"
of the iavf. The first step to fix that is to remove the crit lock.
I will followup with a -next series that simplifies scheduling/tasks.
Cancel the work without netdev lock (weird unlock+lock scheme),
to fix the [splat2] (which would be totally ugly if we would kept
the crit lock).
Extend protected part of iavf_watchdog_task() to include scheduling
more work.
Note that the removed comment in iavf_reset_task() was misplaced,
it belonged to inside of the removed if condition, so it's gone now.
[splat1] - w/o this patch - The deadlock during VF removal:
WARNING: possible circular locking dependency detected
sh/3825 is trying to acquire lock:
((work_completion)(&(&adapter->watchdog_task)->work)){+.+.}-{0:0}, at: start_flush_work+0x1a1/0x470
but task is already holding lock:
(&adapter->crit_lock){+.+.}-{4:4}, at: iavf_remove+0xd1/0x690 [iavf]
which lock already depends on the new lock.
[splat2] - when cancelling work under crit lock, w/o this series,
see [2] for the band aid attempt
WARNING: possible circular locking dependency detected
sh/3550 is trying to acquire lock:
((wq_completion)iavf){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90
but task is already holding lock:
(&dev->lock){+.+.}-{4:4}, at: iavf_remove+0xa6/0x6e0 [iavf]
which lock already depends on the new lock.
[1] fc2e6b3b132a ("iavf: Rework mutexes for better synchronisation")
[2] https://github.com/pkitszel/linux/commit/52dddbfc2bb60294083f5711a158a |
| In the Linux kernel, the following vulnerability has been resolved:
block: don't use submit_bio_noacct_nocheck in blk_zone_wplug_bio_work
Bios queued up in the zone write plug have already gone through all all
preparation in the submit_bio path, including the freeze protection.
Submitting them through submit_bio_noacct_nocheck duplicates the work
and can can cause deadlocks when freezing a queue with pending bio
write plugs.
Go straight to ->submit_bio or blk_mq_submit_bio to bypass the
superfluous extra freeze protection and checks. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tcpm: move tcpm_queue_vdm_unlocked to asynchronous work
A state check was previously added to tcpm_queue_vdm_unlocked to
prevent a deadlock where the DisplayPort Alt Mode driver would be
executing work and attempting to grab the tcpm_lock while the TCPM
was holding the lock and attempting to unregister the altmode, blocking
on the altmode driver's cancel_work_sync call.
Because the state check isn't protected, there is a small window
where the Alt Mode driver could determine that the TCPM is
in a ready state and attempt to grab the lock while the
TCPM grabs the lock and changes the TCPM state to one that
causes the deadlock. The callstack is provided below:
[110121.667392][ C7] Call trace:
[110121.667396][ C7] __switch_to+0x174/0x338
[110121.667406][ C7] __schedule+0x608/0x9f0
[110121.667414][ C7] schedule+0x7c/0xe8
[110121.667423][ C7] kernfs_drain+0xb0/0x114
[110121.667431][ C7] __kernfs_remove+0x16c/0x20c
[110121.667436][ C7] kernfs_remove_by_name_ns+0x74/0xe8
[110121.667442][ C7] sysfs_remove_group+0x84/0xe8
[110121.667450][ C7] sysfs_remove_groups+0x34/0x58
[110121.667458][ C7] device_remove_groups+0x10/0x20
[110121.667464][ C7] device_release_driver_internal+0x164/0x2e4
[110121.667475][ C7] device_release_driver+0x18/0x28
[110121.667484][ C7] bus_remove_device+0xec/0x118
[110121.667491][ C7] device_del+0x1e8/0x4ac
[110121.667498][ C7] device_unregister+0x18/0x38
[110121.667504][ C7] typec_unregister_altmode+0x30/0x44
[110121.667515][ C7] tcpm_reset_port+0xac/0x370
[110121.667523][ C7] tcpm_snk_detach+0x84/0xb8
[110121.667529][ C7] run_state_machine+0x4c0/0x1b68
[110121.667536][ C7] tcpm_state_machine_work+0x94/0xe4
[110121.667544][ C7] kthread_worker_fn+0x10c/0x244
[110121.667552][ C7] kthread+0x104/0x1d4
[110121.667557][ C7] ret_from_fork+0x10/0x20
[110121.667689][ C7] Workqueue: events dp_altmode_work
[110121.667697][ C7] Call trace:
[110121.667701][ C7] __switch_to+0x174/0x338
[110121.667710][ C7] __schedule+0x608/0x9f0
[110121.667717][ C7] schedule+0x7c/0xe8
[110121.667725][ C7] schedule_preempt_disabled+0x24/0x40
[110121.667733][ C7] __mutex_lock+0x408/0xdac
[110121.667741][ C7] __mutex_lock_slowpath+0x14/0x24
[110121.667748][ C7] mutex_lock+0x40/0xec
[110121.667757][ C7] tcpm_altmode_enter+0x78/0xb4
[110121.667764][ C7] typec_altmode_enter+0xdc/0x10c
[110121.667769][ C7] dp_altmode_work+0x68/0x164
[110121.667775][ C7] process_one_work+0x1e4/0x43c
[110121.667783][ C7] worker_thread+0x25c/0x430
[110121.667789][ C7] kthread+0x104/0x1d4
[110121.667794][ C7] ret_from_fork+0x10/0x20
Change tcpm_queue_vdm_unlocked to queue for tcpm_queue_vdm_work,
which can perform the state check while holding the TCPM lock
while the Alt Mode lock is no longer held. This requires a new
struct to hold the vdm data, altmode_vdm_event. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: displayport: Fix deadlock
This patch introduces the ucsi_con_mutex_lock / ucsi_con_mutex_unlock
functions to the UCSI driver. ucsi_con_mutex_lock ensures the connector
mutex is only locked if a connection is established and the partner pointer
is valid. This resolves a deadlock scenario where
ucsi_displayport_remove_partner holds con->mutex waiting for
dp_altmode_work to complete while dp_altmode_work attempts to acquire it. |
| In the Linux kernel, the following vulnerability has been resolved:
ftrace: Add cond_resched() to ftrace_graph_set_hash()
When the kernel contains a large number of functions that can be traced,
the loop in ftrace_graph_set_hash() may take a lot of time to execute.
This may trigger the softlockup watchdog.
Add cond_resched() within the loop to allow the kernel to remain
responsive even when processing a large number of functions.
This matches the cond_resched() that is used in other locations of the
code that iterates over all functions that can be traced. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/ivpu: Fix locking order in ivpu_job_submit
Fix deadlock in job submission and abort handling.
When a thread aborts currently executing jobs due to a fault,
it first locks the global lock protecting submitted_jobs (#1).
After the last job is destroyed, it proceeds to release the related context
and locks file_priv (#2). Meanwhile, in the job submission thread,
the file_priv lock (#2) is taken first, and then the submitted_jobs
lock (#1) is obtained when a job is added to the submitted jobs list.
CPU0 CPU1
---- ----
(for example due to a fault) (jobs submissions keep coming)
lock(&vdev->submitted_jobs_lock) #1
ivpu_jobs_abort_all()
job_destroy()
lock(&file_priv->lock) #2
lock(&vdev->submitted_jobs_lock) #1
file_priv_release()
lock(&vdev->context_list_lock)
lock(&file_priv->lock) #2
This order of locking causes a deadlock. To resolve this issue,
change the order of locking in ivpu_job_submit(). |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock between rcu_tasks_trace and event_mutex.
Fix the following deadlock:
CPU A
_free_event()
perf_kprobe_destroy()
mutex_lock(&event_mutex)
perf_trace_event_unreg()
synchronize_rcu_tasks_trace()
There are several paths where _free_event() grabs event_mutex
and calls sync_rcu_tasks_trace. Above is one such case.
CPU B
bpf_prog_test_run_syscall()
rcu_read_lock_trace()
bpf_prog_run_pin_on_cpu()
bpf_prog_load()
bpf_tracing_func_proto()
trace_set_clr_event()
mutex_lock(&event_mutex)
Delegate trace_set_clr_event() to workqueue to avoid
such lock dependency. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/ivpu: Fix PM related deadlocks in MS IOCTLs
Prevent runtime resume/suspend while MS IOCTLs are in progress.
Failed suspend will call ivpu_ms_cleanup() that would try to acquire
file_priv->ms_lock, which is already held by the IOCTLs. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: pciehp: Avoid unnecessary device replacement check
Hot-removal of nested PCI hotplug ports suffers from a long-standing race
condition which can lead to a deadlock: A parent hotplug port acquires
pci_lock_rescan_remove(), then waits for pciehp to unbind from a child
hotplug port. Meanwhile that child hotplug port tries to acquire
pci_lock_rescan_remove() as well in order to remove its own children.
The deadlock only occurs if the parent acquires pci_lock_rescan_remove()
first, not if the child happens to acquire it first.
Several workarounds to avoid the issue have been proposed and discarded
over the years, e.g.:
https://lore.kernel.org/r/4c882e25194ba8282b78fe963fec8faae7cf23eb.1529173804.git.lukas@wunner.de/
A proper fix is being worked on, but needs more time as it is nontrivial
and necessarily intrusive.
Recent commit 9d573d19547b ("PCI: pciehp: Detect device replacement during
system sleep") provokes more frequent occurrence of the deadlock when
removing more than one Thunderbolt device during system sleep. The commit
sought to detect device replacement, but also triggered on device removal.
Differentiating reliably between replacement and removal is impossible
because pci_get_dsn() returns 0 both if the device was removed, as well as
if it was replaced with one lacking a Device Serial Number.
Avoid the more frequent occurrence of the deadlock by checking whether the
hotplug port itself was hot-removed. If so, there's no sense in checking
whether its child device was replaced.
This works because the ->resume_noirq() callback is invoked in top-down
order for the entire hierarchy: A parent hotplug port detecting device
replacement (or removal) marks all children as removed using
pci_dev_set_disconnected() and a child hotplug port can then reliably
detect being removed. |
| In the Linux kernel, the following vulnerability has been resolved:
PM: hibernate: Avoid deadlock in hibernate_compressor_param_set()
syzbot reported a deadlock in lock_system_sleep() (see below).
The write operation to "/sys/module/hibernate/parameters/compressor"
conflicts with the registration of ieee80211 device, resulting in a deadlock
when attempting to acquire system_transition_mutex under param_lock.
To avoid this deadlock, change hibernate_compressor_param_set() to use
mutex_trylock() for attempting to acquire system_transition_mutex and
return -EBUSY when it fails.
Task flags need not be saved or adjusted before calling
mutex_trylock(&system_transition_mutex) because the caller is not going
to end up waiting for this mutex and if it runs concurrently with system
suspend in progress, it will be frozen properly when it returns to user
space.
syzbot report:
syz-executor895/5833 is trying to acquire lock:
ffffffff8e0828c8 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56
but task is already holding lock:
ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: kernel_param_lock kernel/params.c:607 [inline]
ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: param_attr_store+0xe6/0x300 kernel/params.c:586
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (param_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
ieee80211_rate_control_ops_get net/mac80211/rate.c:220 [inline]
rate_control_alloc net/mac80211/rate.c:266 [inline]
ieee80211_init_rate_ctrl_alg+0x18d/0x6b0 net/mac80211/rate.c:1015
ieee80211_register_hw+0x20cd/0x4060 net/mac80211/main.c:1531
mac80211_hwsim_new_radio+0x304e/0x54e0 drivers/net/wireless/virtual/mac80211_hwsim.c:5558
init_mac80211_hwsim+0x432/0x8c0 drivers/net/wireless/virtual/mac80211_hwsim.c:6910
do_one_initcall+0x128/0x700 init/main.c:1257
do_initcall_level init/main.c:1319 [inline]
do_initcalls init/main.c:1335 [inline]
do_basic_setup init/main.c:1354 [inline]
kernel_init_freeable+0x5c7/0x900 init/main.c:1568
kernel_init+0x1c/0x2b0 init/main.c:1457
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #2 (rtnl_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
wg_pm_notification drivers/net/wireguard/device.c:80 [inline]
wg_pm_notification+0x49/0x180 drivers/net/wireguard/device.c:64
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
notifier_call_chain_robust kernel/notifier.c:120 [inline]
blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline]
blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333
pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102
snapshot_open+0x189/0x2b0 kernel/power/user.c:77
misc_open+0x35a/0x420 drivers/char/misc.c:179
chrdev_open+0x237/0x6a0 fs/char_dev.c:414
do_dentry_open+0x735/0x1c40 fs/open.c:956
vfs_open+0x82/0x3f0 fs/open.c:1086
do_open fs/namei.c:3830 [inline]
path_openat+0x1e88/0x2d80 fs/namei.c:3989
do_filp_open+0x20c/0x470 fs/namei.c:4016
do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1454
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 ((pm_chain_head).rwsem){++++}-{4:4}:
down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
blocking_notifier_call_chain_robust kerne
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: vlan: don't propagate flags on open
With the device instance lock, there is now a possibility of a deadlock:
[ 1.211455] ============================================
[ 1.211571] WARNING: possible recursive locking detected
[ 1.211687] 6.14.0-rc5-01215-g032756b4ca7a-dirty #5 Not tainted
[ 1.211823] --------------------------------------------
[ 1.211936] ip/184 is trying to acquire lock:
[ 1.212032] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_set_allmulti+0x4e/0xb0
[ 1.212207]
[ 1.212207] but task is already holding lock:
[ 1.212332] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0
[ 1.212487]
[ 1.212487] other info that might help us debug this:
[ 1.212626] Possible unsafe locking scenario:
[ 1.212626]
[ 1.212751] CPU0
[ 1.212815] ----
[ 1.212871] lock(&dev->lock);
[ 1.212944] lock(&dev->lock);
[ 1.213016]
[ 1.213016] *** DEADLOCK ***
[ 1.213016]
[ 1.213143] May be due to missing lock nesting notation
[ 1.213143]
[ 1.213294] 3 locks held by ip/184:
[ 1.213371] #0: ffffffff838b53e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x1b/0xa0
[ 1.213543] #1: ffffffff84e5fc70 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x37/0xa0
[ 1.213727] #2: ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0
[ 1.213895]
[ 1.213895] stack backtrace:
[ 1.213991] CPU: 0 UID: 0 PID: 184 Comm: ip Not tainted 6.14.0-rc5-01215-g032756b4ca7a-dirty #5
[ 1.213993] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[ 1.213994] Call Trace:
[ 1.213995] <TASK>
[ 1.213996] dump_stack_lvl+0x8e/0xd0
[ 1.214000] print_deadlock_bug+0x28b/0x2a0
[ 1.214020] lock_acquire+0xea/0x2a0
[ 1.214027] __mutex_lock+0xbf/0xd40
[ 1.214038] dev_set_allmulti+0x4e/0xb0 # real_dev->flags & IFF_ALLMULTI
[ 1.214040] vlan_dev_open+0xa5/0x170 # ndo_open on vlandev
[ 1.214042] __dev_open+0x145/0x270
[ 1.214046] __dev_change_flags+0xb0/0x1e0
[ 1.214051] netif_change_flags+0x22/0x60 # IFF_UP vlandev
[ 1.214053] dev_change_flags+0x61/0xb0 # for each device in group from dev->vlan_info
[ 1.214055] vlan_device_event+0x766/0x7c0 # on netdevsim0
[ 1.214058] notifier_call_chain+0x78/0x120
[ 1.214062] netif_open+0x6d/0x90
[ 1.214064] dev_open+0x5b/0xb0 # locks netdevsim0
[ 1.214066] bond_enslave+0x64c/0x1230
[ 1.214075] do_set_master+0x175/0x1e0 # on netdevsim0
[ 1.214077] do_setlink+0x516/0x13b0
[ 1.214094] rtnl_newlink+0xaba/0xb80
[ 1.214132] rtnetlink_rcv_msg+0x440/0x490
[ 1.214144] netlink_rcv_skb+0xeb/0x120
[ 1.214150] netlink_unicast+0x1f9/0x320
[ 1.214153] netlink_sendmsg+0x346/0x3f0
[ 1.214157] __sock_sendmsg+0x86/0xb0
[ 1.214160] ____sys_sendmsg+0x1c8/0x220
[ 1.214164] ___sys_sendmsg+0x28f/0x2d0
[ 1.214179] __x64_sys_sendmsg+0xef/0x140
[ 1.214184] do_syscall_64+0xec/0x1d0
[ 1.214190] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 1.214191] RIP: 0033:0x7f2d1b4a7e56
Device setup:
netdevsim0 (down)
^ ^
bond netdevsim1.100@netdevsim1 allmulticast=on (down)
When we enslave the lower device (netdevsim0) which has a vlan, we
propagate vlan's allmuti/promisc flags during ndo_open. This causes
(re)locking on of the real_dev.
Propagate allmulti/promisc on flags change, not on the open. There
is a slight semantics change that vlans that are down now propagate
the flags, but this seems unlikely to result in the real issues.
Reproducer:
echo 0 1 > /sys/bus/netdevsim/new_device
dev_path=$(ls -d /sys/bus/netdevsim/devices/netdevsim0/net/*)
dev=$(echo $dev_path | rev | cut -d/ -f1 | rev)
ip link set dev $dev name netdevsim0
ip link set dev netdevsim0 up
ip link add link netdevsim0 name netdevsim0.100 type vlan id 100
ip link set dev netdevsim0.100 allm
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type
The access to the PCI config space via pci_ops::read and pci_ops::write is
a low-level hardware access. The functions can be accessed with disabled
interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this
purpose.
A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be
acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in
the same context as the pci_lock.
Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with
interrupts disabled.
This was reported as:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
Call Trace:
rt_spin_lock+0x4e/0x130
vmd_pci_read+0x8d/0x100 [vmd]
pci_user_read_config_byte+0x6f/0xe0
pci_read_config+0xfe/0x290
sysfs_kf_bin_read+0x68/0x90
[bigeasy: reword commit message]
Tested-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
[kwilczynski: commit log]
[bhelgaas: add back report info from
https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/] |
| In the Linux kernel, the following vulnerability has been resolved:
net: ibmveth: make veth_pool_store stop hanging
v2:
- Created a single error handling unlock and exit in veth_pool_store
- Greatly expanded commit message with previous explanatory-only text
Summary: Use rtnl_mutex to synchronize veth_pool_store with itself,
ibmveth_close and ibmveth_open, preventing multiple calls in a row to
napi_disable.
Background: Two (or more) threads could call veth_pool_store through
writing to /sys/devices/vio/30000002/pool*/*. You can do this easily
with a little shell script. This causes a hang.
I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new
kernel. I ran this test again and saw:
Setting pool0/active to 0
Setting pool1/active to 1
[ 73.911067][ T4365] ibmveth 30000002 eth0: close starting
Setting pool1/active to 1
Setting pool1/active to 0
[ 73.911367][ T4366] ibmveth 30000002 eth0: close starting
[ 73.916056][ T4365] ibmveth 30000002 eth0: close complete
[ 73.916064][ T4365] ibmveth 30000002 eth0: open starting
[ 110.808564][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
[ 230.808495][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
[ 243.683786][ T123] INFO: task stress.sh:4365 blocked for more than 122 seconds.
[ 243.683827][ T123] Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8
[ 243.683833][ T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 243.683838][ T123] task:stress.sh state:D stack:28096 pid:4365 tgid:4365 ppid:4364 task_flags:0x400040 flags:0x00042000
[ 243.683852][ T123] Call Trace:
[ 243.683857][ T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable)
[ 243.683868][ T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0
[ 243.683878][ T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0
[ 243.683888][ T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210
[ 243.683896][ T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50
[ 243.683904][ T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0
[ 243.683913][ T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60
[ 243.683921][ T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc
[ 243.683928][ T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270
[ 243.683936][ T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0
[ 243.683944][ T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0
[ 243.683951][ T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650
[ 243.683958][ T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150
[ 243.683966][ T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340
[ 243.683973][ T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
...
[ 243.684087][ T123] Showing all locks held in the system:
[ 243.684095][ T123] 1 lock held by khungtaskd/123:
[ 243.684099][ T123] #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248
[ 243.684114][ T123] 4 locks held by stress.sh/4365:
[ 243.684119][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
[ 243.684132][ T123] #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
[ 243.684143][ T123] #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
[ 243.684155][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60
[ 243.684166][ T123] 5 locks held by stress.sh/4366:
[ 243.684170][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
[ 243.
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: switchdev: Convert blocking notification chain to a raw one
A blocking notification chain uses a read-write semaphore to protect the
integrity of the chain. The semaphore is acquired for writing when
adding / removing notifiers to / from the chain and acquired for reading
when traversing the chain and informing notifiers about an event.
In case of the blocking switchdev notification chain, recursive
notifications are possible which leads to the semaphore being acquired
twice for reading and to lockdep warnings being generated [1].
Specifically, this can happen when the bridge driver processes a
SWITCHDEV_BRPORT_UNOFFLOADED event which causes it to emit notifications
about deferred events when calling switchdev_deferred_process().
Fix this by converting the notification chain to a raw notification
chain in a similar fashion to the netdev notification chain. Protect
the chain using the RTNL mutex by acquiring it when modifying the chain.
Events are always informed under the RTNL mutex, but add an assertion in
call_switchdev_blocking_notifiers() to make sure this is not violated in
the future.
Maintain the "blocking" prefix as events are always emitted from process
context and listeners are allowed to block.
[1]:
WARNING: possible recursive locking detected
6.14.0-rc4-custom-g079270089484 #1 Not tainted
--------------------------------------------
ip/52731 is trying to acquire lock:
ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0
but task is already holding lock:
ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock((switchdev_blocking_notif_chain).rwsem);
lock((switchdev_blocking_notif_chain).rwsem);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by ip/52731:
#0: ffffffff84f795b0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x727/0x1dc0
#1: ffffffff8731f628 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x790/0x1dc0
#2: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0
stack backtrace:
...
? __pfx_down_read+0x10/0x10
? __pfx_mark_lock+0x10/0x10
? __pfx_switchdev_port_attr_set_deferred+0x10/0x10
blocking_notifier_call_chain+0x58/0xa0
switchdev_port_attr_notify.constprop.0+0xb3/0x1b0
? __pfx_switchdev_port_attr_notify.constprop.0+0x10/0x10
? mark_held_locks+0x94/0xe0
? switchdev_deferred_process+0x11a/0x340
switchdev_port_attr_set_deferred+0x27/0xd0
switchdev_deferred_process+0x164/0x340
br_switchdev_port_unoffload+0xc8/0x100 [bridge]
br_switchdev_blocking_event+0x29f/0x580 [bridge]
notifier_call_chain+0xa2/0x440
blocking_notifier_call_chain+0x6e/0xa0
switchdev_bridge_port_unoffload+0xde/0x1a0
... |
| In the Linux kernel, the following vulnerability has been resolved:
block: mark GFP_NOIO around sysfs ->store()
sysfs ->store is called with queue freezed, meantime we have several
->store() callbacks(update_nr_requests, wbt, scheduler) to allocate
memory with GFP_KERNEL which may run into direct reclaim code path,
then potential deadlock can be caused.
Fix the issue by marking NOIO around sysfs ->store() |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix queue freeze vs limits lock order in sysfs store methods
queue_attr_store() always freezes a device queue before calling the
attribute store operation. For attributes that control queue limits, the
store operation will also lock the queue limits with a call to
queue_limits_start_update(). However, some drivers (e.g. SCSI sd) may
need to issue commands to a device to obtain limit values from the
hardware with the queue limits locked. This creates a potential ABBA
deadlock situation if a user attempts to modify a limit (thus freezing
the device queue) while the device driver starts a revalidation of the
device queue limits.
Avoid such deadlock by not freezing the queue before calling the
->store_limit() method in struct queue_sysfs_entry and instead use the
queue_limits_commit_update_frozen helper to freeze the queue after taking
the limits lock.
This also removes taking the sysfs lock for the store_limit method as
it doesn't protect anything here, but creates even more nesting.
Hopefully it will go away from the actual sysfs methods entirely soon.
(commit log adapted from a similar patch from Damien Le Moal) |
| In the Linux kernel, the following vulnerability has been resolved:
clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context
The following bug report happened with a PREEMPT_RT kernel:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2012, name: kwatchdog
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
get_random_u32+0x4f/0x110
clocksource_verify_choose_cpus+0xab/0x1a0
clocksource_verify_percpu.part.0+0x6b/0x330
clocksource_watchdog_kthread+0x193/0x1a0
It is due to the fact that clocksource_verify_choose_cpus() is invoked with
preemption disabled. This function invokes get_random_u32() to obtain
random numbers for choosing CPUs. The batched_entropy_32 local lock and/or
the base_crng.lock spinlock in driver/char/random.c will be acquired during
the call. In PREEMPT_RT kernel, they are both sleeping locks and so cannot
be acquired in atomic context.
Fix this problem by using migrate_disable() to allow smp_processor_id() to
be reliably used without introducing atomic context. preempt_disable() is
then called after clocksource_verify_choose_cpus() but before the
clocksource measurement is being run to avoid introducing unexpected
latency. |
| In the Linux kernel, the following vulnerability has been resolved:
ptr_ring: do not block hard interrupts in ptr_ring_resize_multiple()
Jakub added a lockdep_assert_no_hardirq() check in __page_pool_put_page()
to increase test coverage.
syzbot found a splat caused by hard irq blocking in
ptr_ring_resize_multiple() [1]
As current users of ptr_ring_resize_multiple() do not require
hard irqs being masked, replace it to only block BH.
Rename helpers to better reflect they are safe against BH only.
- ptr_ring_resize_multiple() to ptr_ring_resize_multiple_bh()
- skb_array_resize_multiple() to skb_array_resize_multiple_bh()
[1]
WARNING: CPU: 1 PID: 9150 at net/core/page_pool.c:709 __page_pool_put_page net/core/page_pool.c:709 [inline]
WARNING: CPU: 1 PID: 9150 at net/core/page_pool.c:709 page_pool_put_unrefed_netmem+0x157/0xa40 net/core/page_pool.c:780
Modules linked in:
CPU: 1 UID: 0 PID: 9150 Comm: syz.1.1052 Not tainted 6.11.0-rc3-syzkaller-00202-gf8669d7b5f5d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:__page_pool_put_page net/core/page_pool.c:709 [inline]
RIP: 0010:page_pool_put_unrefed_netmem+0x157/0xa40 net/core/page_pool.c:780
Code: 74 0e e8 7c aa fb f7 eb 43 e8 75 aa fb f7 eb 3c 65 8b 1d 38 a8 6a 76 31 ff 89 de e8 a3 ae fb f7 85 db 74 0b e8 5a aa fb f7 90 <0f> 0b 90 eb 1d 65 8b 1d 15 a8 6a 76 31 ff 89 de e8 84 ae fb f7 85
RSP: 0018:ffffc9000bda6b58 EFLAGS: 00010083
RAX: ffffffff8997e523 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc9000fbd0000 RSI: 0000000000001842 RDI: 0000000000001843
RBP: 0000000000000000 R08: ffffffff8997df2c R09: 1ffffd40003a000d
R10: dffffc0000000000 R11: fffff940003a000e R12: ffffea0001d00040
R13: ffff88802e8a4000 R14: dffffc0000000000 R15: 00000000ffffffff
FS: 00007fb7aaf716c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa15a0d4b72 CR3: 00000000561b0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tun_ptr_free drivers/net/tun.c:617 [inline]
__ptr_ring_swap_queue include/linux/ptr_ring.h:571 [inline]
ptr_ring_resize_multiple_noprof include/linux/ptr_ring.h:643 [inline]
tun_queue_resize drivers/net/tun.c:3694 [inline]
tun_device_event+0xaaf/0x1080 drivers/net/tun.c:3714
notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
call_netdevice_notifiers net/core/dev.c:2046 [inline]
dev_change_tx_queue_len+0x158/0x2a0 net/core/dev.c:9024
do_setlink+0xff6/0x41f0 net/core/rtnetlink.c:2923
rtnl_setlink+0x40d/0x5a0 net/core/rtnetlink.c:3201
rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6647
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550 |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries: Fix dtl_access_lock to be a rw_semaphore
The dtl_access_lock needs to be a rw_sempahore, a sleeping lock, because
the code calls kmalloc() while holding it, which can sleep:
# echo 1 > /proc/powerpc/vcpudispatch_stats
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:337
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 199, name: sh
preempt_count: 1, expected: 0
3 locks held by sh/199:
#0: c00000000a0743f8 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x324/0x438
#1: c0000000028c7058 (dtl_enable_mutex){+.+.}-{3:3}, at: vcpudispatch_stats_write+0xd4/0x5f4
#2: c0000000028c70b8 (dtl_access_lock){+.+.}-{2:2}, at: vcpudispatch_stats_write+0x220/0x5f4
CPU: 0 PID: 199 Comm: sh Not tainted 6.10.0-rc4 #152
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
Call Trace:
dump_stack_lvl+0x130/0x148 (unreliable)
__might_resched+0x174/0x410
kmem_cache_alloc_noprof+0x340/0x3d0
alloc_dtl_buffers+0x124/0x1ac
vcpudispatch_stats_write+0x2a8/0x5f4
proc_reg_write+0xf4/0x150
vfs_write+0xfc/0x438
ksys_write+0x88/0x148
system_call_exception+0x1c4/0x5a0
system_call_common+0xf4/0x258 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Use raw_spinlock_t in ringbuf
The function __bpf_ringbuf_reserve is invoked from a tracepoint, which
disables preemption. Using spinlock_t in this context can lead to a
"sleep in atomic" warning in the RT variant. This issue is illustrated
in the example below:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 556208, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffd33a5c88ea44>] migrate_enable+0xc0/0x39c
CPU: 7 PID: 556208 Comm: test_progs Tainted: G
Hardware name: Qualcomm SA8775P Ride (DT)
Call trace:
dump_backtrace+0xac/0x130
show_stack+0x1c/0x30
dump_stack_lvl+0xac/0xe8
dump_stack+0x18/0x30
__might_resched+0x3bc/0x4fc
rt_spin_lock+0x8c/0x1a4
__bpf_ringbuf_reserve+0xc4/0x254
bpf_ringbuf_reserve_dynptr+0x5c/0xdc
bpf_prog_ac3d15160d62622a_test_read_write+0x104/0x238
trace_call_bpf+0x238/0x774
perf_call_bpf_enter.isra.0+0x104/0x194
perf_syscall_enter+0x2f8/0x510
trace_sys_enter+0x39c/0x564
syscall_trace_enter+0x220/0x3c0
do_el0_svc+0x138/0x1dc
el0_svc+0x54/0x130
el0t_64_sync_handler+0x134/0x150
el0t_64_sync+0x17c/0x180
Switch the spinlock to raw_spinlock_t to avoid this error. |
