| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Get rid of userspace_irqchip_in_use
Improper use of userspace_irqchip_in_use led to syzbot hitting the
following WARN_ON() in kvm_timer_update_irq():
WARNING: CPU: 0 PID: 3281 at arch/arm64/kvm/arch_timer.c:459
kvm_timer_update_irq+0x21c/0x394
Call trace:
kvm_timer_update_irq+0x21c/0x394 arch/arm64/kvm/arch_timer.c:459
kvm_timer_vcpu_reset+0x158/0x684 arch/arm64/kvm/arch_timer.c:968
kvm_reset_vcpu+0x3b4/0x560 arch/arm64/kvm/reset.c:264
kvm_vcpu_set_target arch/arm64/kvm/arm.c:1553 [inline]
kvm_arch_vcpu_ioctl_vcpu_init arch/arm64/kvm/arm.c:1573 [inline]
kvm_arch_vcpu_ioctl+0x112c/0x1b3c arch/arm64/kvm/arm.c:1695
kvm_vcpu_ioctl+0x4ec/0xf74 virt/kvm/kvm_main.c:4658
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__arm64_sys_ioctl+0x108/0x184 fs/ioctl.c:893
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x78/0x1b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xe8/0x1b0 arch/arm64/kernel/syscall.c:132
do_el0_svc+0x40/0x50 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x14c arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
The following sequence led to the scenario:
- Userspace creates a VM and a vCPU.
- The vCPU is initialized with KVM_ARM_VCPU_PMU_V3 during
KVM_ARM_VCPU_INIT.
- Without any other setup, such as vGIC or vPMU, userspace issues
KVM_RUN on the vCPU. Since the vPMU is requested, but not setup,
kvm_arm_pmu_v3_enable() fails in kvm_arch_vcpu_run_pid_change().
As a result, KVM_RUN returns after enabling the timer, but before
incrementing 'userspace_irqchip_in_use':
kvm_arch_vcpu_run_pid_change()
ret = kvm_arm_pmu_v3_enable()
if (!vcpu->arch.pmu.created)
return -EINVAL;
if (ret)
return ret;
[...]
if (!irqchip_in_kernel(kvm))
static_branch_inc(&userspace_irqchip_in_use);
- Userspace ignores the error and issues KVM_ARM_VCPU_INIT again.
Since the timer is already enabled, control moves through the
following flow, ultimately hitting the WARN_ON():
kvm_timer_vcpu_reset()
if (timer->enabled)
kvm_timer_update_irq()
if (!userspace_irqchip())
ret = kvm_vgic_inject_irq()
ret = vgic_lazy_init()
if (unlikely(!vgic_initialized(kvm)))
if (kvm->arch.vgic.vgic_model !=
KVM_DEV_TYPE_ARM_VGIC_V2)
return -EBUSY;
WARN_ON(ret);
Theoretically, since userspace_irqchip_in_use's functionality can be
simply replaced by '!irqchip_in_kernel()', get rid of the static key
to avoid the mismanagement, which also helps with the syzbot issue. |
| In the Linux kernel, the following vulnerability has been resolved:
pmdomain: imx93-blk-ctrl: correct remove path
The check condition should be 'i < bc->onecell_data.num_domains', not
'bc->onecell_data.num_domains' which will make the look never finish
and cause kernel panic.
Also disable runtime to address
"imx93-blk-ctrl 4ac10000.system-controller: Unbalanced pm_runtime_enable!" |
| In the Linux kernel, the following vulnerability has been resolved:
x86/CPU/AMD: Clear virtualized VMLOAD/VMSAVE on Zen4 client
A number of Zen4 client SoCs advertise the ability to use virtualized
VMLOAD/VMSAVE, but using these instructions is reported to be a cause
of a random host reboot.
These instructions aren't intended to be advertised on Zen4 client
so clear the capability. |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix lock recursion
afs_wake_up_async_call() can incur lock recursion. The problem is that it
is called from AF_RXRPC whilst holding the ->notify_lock, but it tries to
take a ref on the afs_call struct in order to pass it to a work queue - but
if the afs_call is already queued, we then have an extraneous ref that must
be put... calling afs_put_call() may call back down into AF_RXRPC through
rxrpc_kernel_shutdown_call(), however, which might try taking the
->notify_lock again.
This case isn't very common, however, so defer it to a workqueue. The oops
looks something like:
BUG: spinlock recursion on CPU#0, krxrpcio/7001/1646
lock: 0xffff888141399b30, .magic: dead4ead, .owner: krxrpcio/7001/1646, .owner_cpu: 0
CPU: 0 UID: 0 PID: 1646 Comm: krxrpcio/7001 Not tainted 6.12.0-rc2-build3+ #4351
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x70
do_raw_spin_lock+0x3c/0x90
rxrpc_kernel_shutdown_call+0x83/0xb0
afs_put_call+0xd7/0x180
rxrpc_notify_socket+0xa0/0x190
rxrpc_input_split_jumbo+0x198/0x1d0
rxrpc_input_data+0x14b/0x1e0
? rxrpc_input_call_packet+0xc2/0x1f0
rxrpc_input_call_event+0xad/0x6b0
rxrpc_input_packet_on_conn+0x1e1/0x210
rxrpc_input_packet+0x3f2/0x4d0
rxrpc_io_thread+0x243/0x410
? __pfx_rxrpc_io_thread+0x10/0x10
kthread+0xcf/0xe0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x24/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
l2tp: prevent possible tunnel refcount underflow
When a session is created, it sets a backpointer to its tunnel. When
the session refcount drops to 0, l2tp_session_free drops the tunnel
refcount if session->tunnel is non-NULL. However, session->tunnel is
set in l2tp_session_create, before the tunnel refcount is incremented
by l2tp_session_register, which leaves a small window where
session->tunnel is non-NULL when the tunnel refcount hasn't been
bumped.
Moving the assignment to l2tp_session_register is trivial but
l2tp_session_create calls l2tp_session_set_header_len which uses
session->tunnel to get the tunnel's encap. Add an encap arg to
l2tp_session_set_header_len to avoid using session->tunnel.
If l2tpv3 sessions have colliding IDs, it is possible for
l2tp_v3_session_get to race with l2tp_session_register and fetch a
session which doesn't yet have session->tunnel set. Add a check for
this case. |
| In the Linux kernel, the following vulnerability has been resolved:
pinmux: Use sequential access to access desc->pinmux data
When two client of the same gpio call pinctrl_select_state() for the
same functionality, we are seeing NULL pointer issue while accessing
desc->mux_owner.
Let's say two processes A, B executing in pin_request() for the same pin
and process A updates the desc->mux_usecount but not yet updated the
desc->mux_owner while process B see the desc->mux_usecount which got
updated by A path and further executes strcmp and while accessing
desc->mux_owner it crashes with NULL pointer.
Serialize the access to mux related setting with a mutex lock.
cpu0 (process A) cpu1(process B)
pinctrl_select_state() { pinctrl_select_state() {
pin_request() { pin_request() {
...
....
} else {
desc->mux_usecount++;
desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
if (desc->mux_usecount > 1)
return 0;
desc->mux_owner = owner;
} } |
| In the Linux kernel, the following vulnerability has been resolved:
pktgen: use cpus_read_lock() in pg_net_init()
I have seen the WARN_ON(smp_processor_id() != cpu) firing
in pktgen_thread_worker() during tests.
We must use cpus_read_lock()/cpus_read_unlock()
around the for_each_online_cpu(cpu) loop.
While we are at it use WARN_ON_ONCE() to avoid a possible syslog flood. |
| In the Linux kernel, the following vulnerability has been resolved:
serial: sc16is7xx: fix TX fifo corruption
Sometimes, when a packet is received on channel A at almost the same time
as a packet is about to be transmitted on channel B, we observe with a
logic analyzer that the received packet on channel A is transmitted on
channel B. In other words, the Tx buffer data on channel B is corrupted
with data from channel A.
The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change
EFR lock to operate on each channels"), which changed the EFR locking to
operate on each channel instead of chip-wise.
This commit has introduced a regression, because the EFR lock is used not
only to protect the EFR registers access, but also, in a very obscure and
undocumented way, to protect access to the data buffer, which is shared by
the Tx and Rx handlers, but also by each channel of the IC.
Fix this regression first by switching to kfifo_out_linear_ptr() in
sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer.
Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for
each channel. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/hns: Fix soft lockup under heavy CEQE load
CEQEs are handled in interrupt handler currently. This may cause the
CPU core staying in interrupt context too long and lead to soft lockup
under heavy load.
Handle CEQEs in BH workqueue and set an upper limit for the number of
CEQE handled by a single call of work handler. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fail bpf_timer_cancel when callback is being cancelled
Given a schedule:
timer1 cb timer2 cb
bpf_timer_cancel(timer2); bpf_timer_cancel(timer1);
Both bpf_timer_cancel calls would wait for the other callback to finish
executing, introducing a lockup.
Add an atomic_t count named 'cancelling' in bpf_hrtimer. This keeps
track of all in-flight cancellation requests for a given BPF timer.
Whenever cancelling a BPF timer, we must check if we have outstanding
cancellation requests, and if so, we must fail the operation with an
error (-EDEADLK) since cancellation is synchronous and waits for the
callback to finish executing. This implies that we can enter a deadlock
situation involving two or more timer callbacks executing in parallel
and attempting to cancel one another.
Note that we avoid incrementing the cancelling counter for the target
timer (the one being cancelled) if bpf_timer_cancel is not invoked from
a callback, to avoid spurious errors. The whole point of detecting
cur->cancelling and returning -EDEADLK is to not enter a busy wait loop
(which may or may not lead to a lockup). This does not apply in case the
caller is in a non-callback context, the other side can continue to
cancel as it sees fit without running into errors.
Background on prior attempts:
Earlier versions of this patch used a bool 'cancelling' bit and used the
following pattern under timer->lock to publish cancellation status.
lock(t->lock);
t->cancelling = true;
mb();
if (cur->cancelling)
return -EDEADLK;
unlock(t->lock);
hrtimer_cancel(t->timer);
t->cancelling = false;
The store outside the critical section could overwrite a parallel
requests t->cancelling assignment to true, to ensure the parallely
executing callback observes its cancellation status.
It would be necessary to clear this cancelling bit once hrtimer_cancel
is done, but lack of serialization introduced races. Another option was
explored where bpf_timer_start would clear the bit when (re)starting the
timer under timer->lock. This would ensure serialized access to the
cancelling bit, but may allow it to be cleared before in-flight
hrtimer_cancel has finished executing, such that lockups can occur
again.
Thus, we choose an atomic counter to keep track of all outstanding
cancellation requests and use it to prevent lockups in case callbacks
attempt to cancel each other while executing in parallel. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/pkey: Use kfree_sensitive() to fix Coccinelle warnings
Replace memzero_explicit() and kfree() with kfree_sensitive() to fix
warnings reported by Coccinelle:
WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1506)
WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1643)
WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1770) |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Reload only IB representors upon lag disable/enable
On lag disable, the bond IB device along with all of its
representors are destroyed, and then the slaves' representors get reloaded.
In case the slave IB representor load fails, the eswitch error flow
unloads all representors, including ethernet representors, where the
netdevs get detached and removed from lag bond. Such flow is inaccurate
as the lag driver is not responsible for loading/unloading ethernet
representors. Furthermore, the flow described above begins by holding
lag lock to prevent bond changes during disable flow. However, when
reaching the ethernet representors detachment from lag, the lag lock is
required again, triggering the following deadlock:
Call trace:
__switch_to+0xf4/0x148
__schedule+0x2c8/0x7d0
schedule+0x50/0xe0
schedule_preempt_disabled+0x18/0x28
__mutex_lock.isra.13+0x2b8/0x570
__mutex_lock_slowpath+0x1c/0x28
mutex_lock+0x4c/0x68
mlx5_lag_remove_netdev+0x3c/0x1a0 [mlx5_core]
mlx5e_uplink_rep_disable+0x70/0xa0 [mlx5_core]
mlx5e_detach_netdev+0x6c/0xb0 [mlx5_core]
mlx5e_netdev_change_profile+0x44/0x138 [mlx5_core]
mlx5e_netdev_attach_nic_profile+0x28/0x38 [mlx5_core]
mlx5e_vport_rep_unload+0x184/0x1b8 [mlx5_core]
mlx5_esw_offloads_rep_load+0xd8/0xe0 [mlx5_core]
mlx5_eswitch_reload_reps+0x74/0xd0 [mlx5_core]
mlx5_disable_lag+0x130/0x138 [mlx5_core]
mlx5_lag_disable_change+0x6c/0x70 [mlx5_core] // hold ldev->lock
mlx5_devlink_eswitch_mode_set+0xc0/0x410 [mlx5_core]
devlink_nl_cmd_eswitch_set_doit+0xdc/0x180
genl_family_rcv_msg_doit.isra.17+0xe8/0x138
genl_rcv_msg+0xe4/0x220
netlink_rcv_skb+0x44/0x108
genl_rcv+0x40/0x58
netlink_unicast+0x198/0x268
netlink_sendmsg+0x1d4/0x418
sock_sendmsg+0x54/0x60
__sys_sendto+0xf4/0x120
__arm64_sys_sendto+0x30/0x40
el0_svc_common+0x8c/0x120
do_el0_svc+0x30/0xa0
el0_svc+0x20/0x30
el0_sync_handler+0x90/0xb8
el0_sync+0x160/0x180
Thus, upon lag enable/disable, load and unload only the IB representors
of the slaves preventing the deadlock mentioned above.
While at it, refactor the mlx5_esw_offloads_rep_load() function to have
a static helper method for its internal logic, in symmetry with the
representor unload design. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock with fiemap and extent locking
While working on the patchset to remove extent locking I got a lockdep
splat with fiemap and pagefaulting with my new extent lock replacement
lock.
This deadlock exists with our normal code, we just don't have lockdep
annotations with the extent locking so we've never noticed it.
Since we're copying the fiemap extent to user space on every iteration
we have the chance of pagefaulting. Because we hold the extent lock for
the entire range we could mkwrite into a range in the file that we have
mmap'ed. This would deadlock with the following stack trace
[<0>] lock_extent+0x28d/0x2f0
[<0>] btrfs_page_mkwrite+0x273/0x8a0
[<0>] do_page_mkwrite+0x50/0xb0
[<0>] do_fault+0xc1/0x7b0
[<0>] __handle_mm_fault+0x2fa/0x460
[<0>] handle_mm_fault+0xa4/0x330
[<0>] do_user_addr_fault+0x1f4/0x800
[<0>] exc_page_fault+0x7c/0x1e0
[<0>] asm_exc_page_fault+0x26/0x30
[<0>] rep_movs_alternative+0x33/0x70
[<0>] _copy_to_user+0x49/0x70
[<0>] fiemap_fill_next_extent+0xc8/0x120
[<0>] emit_fiemap_extent+0x4d/0xa0
[<0>] extent_fiemap+0x7f8/0xad0
[<0>] btrfs_fiemap+0x49/0x80
[<0>] __x64_sys_ioctl+0x3e1/0xb50
[<0>] do_syscall_64+0x94/0x1a0
[<0>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
I wrote an fstest to reproduce this deadlock without my replacement lock
and verified that the deadlock exists with our existing locking.
To fix this simply don't take the extent lock for the entire duration of
the fiemap. This is safe in general because we keep track of where we
are when we're searching the tree, so if an ordered extent updates in
the middle of our fiemap call we'll still emit the correct extents
because we know what offset we were on before.
The only place we maintain the lock is searching delalloc. Since the
delalloc stuff can change during writeback we want to lock the extent
range so we have a consistent view of delalloc at the time we're
checking to see if we need to set the delalloc flag.
With this patch applied we no longer deadlock with my testcase. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: Fix mirred deadlock on device recursion
When the mirred action is used on a classful egress qdisc and a packet is
mirrored or redirected to self we hit a qdisc lock deadlock.
See trace below.
[..... other info removed for brevity....]
[ 82.890906]
[ 82.890906] ============================================
[ 82.890906] WARNING: possible recursive locking detected
[ 82.890906] 6.8.0-05205-g77fadd89fe2d-dirty #213 Tainted: G W
[ 82.890906] --------------------------------------------
[ 82.890906] ping/418 is trying to acquire lock:
[ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at:
__dev_queue_xmit+0x1778/0x3550
[ 82.890906]
[ 82.890906] but task is already holding lock:
[ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at:
__dev_queue_xmit+0x1778/0x3550
[ 82.890906]
[ 82.890906] other info that might help us debug this:
[ 82.890906] Possible unsafe locking scenario:
[ 82.890906]
[ 82.890906] CPU0
[ 82.890906] ----
[ 82.890906] lock(&sch->q.lock);
[ 82.890906] lock(&sch->q.lock);
[ 82.890906]
[ 82.890906] *** DEADLOCK ***
[ 82.890906]
[..... other info removed for brevity....]
Example setup (eth0->eth0) to recreate
tc qdisc add dev eth0 root handle 1: htb default 30
tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \
action mirred egress redirect dev eth0
Another example(eth0->eth1->eth0) to recreate
tc qdisc add dev eth0 root handle 1: htb default 30
tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \
action mirred egress redirect dev eth1
tc qdisc add dev eth1 root handle 1: htb default 30
tc filter add dev eth1 handle 1: protocol ip prio 2 matchall \
action mirred egress redirect dev eth0
We fix this by adding an owner field (CPU id) to struct Qdisc set after
root qdisc is entered. When the softirq enters it a second time, if the
qdisc owner is the same CPU, the packet is dropped to break the loop. |
| In the Linux kernel, the following vulnerability has been resolved:
interconnect: Don't access req_list while it's being manipulated
The icc_lock mutex was split into separate icc_lock and icc_bw_lock
mutexes in [1] to avoid lockdep splats. However, this didn't adequately
protect access to icc_node::req_list.
The icc_set_bw() function will eventually iterate over req_list while
only holding icc_bw_lock, but req_list can be modified while only
holding icc_lock. This causes races between icc_set_bw(), of_icc_get(),
and icc_put().
Example A:
CPU0 CPU1
---- ----
icc_set_bw(path_a)
mutex_lock(&icc_bw_lock);
icc_put(path_b)
mutex_lock(&icc_lock);
aggregate_requests()
hlist_for_each_entry(r, ...
hlist_del(...
<r = invalid pointer>
Example B:
CPU0 CPU1
---- ----
icc_set_bw(path_a)
mutex_lock(&icc_bw_lock);
path_b = of_icc_get()
of_icc_get_by_index()
mutex_lock(&icc_lock);
path_find()
path_init()
aggregate_requests()
hlist_for_each_entry(r, ...
hlist_add_head(...
<r = invalid pointer>
Fix this by ensuring icc_bw_lock is always held before manipulating
icc_node::req_list. The additional places icc_bw_lock is held don't
perform any memory allocations, so we should still be safe from the
original lockdep splats that motivated the separate locks.
[1] commit af42269c3523 ("interconnect: Fix locking for runpm vs reclaim") |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: hisi_sas: Fix a deadlock issue related to automatic dump
If we issue a disabling PHY command, the device attached with it will go
offline, if a 2 bit ECC error occurs at the same time, a hung task may be
found:
[ 4613.652388] INFO: task kworker/u256:0:165233 blocked for more than 120 seconds.
[ 4613.666297] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4613.674809] task:kworker/u256:0 state:D stack: 0 pid:165233 ppid: 2 flags:0x00000208
[ 4613.683959] Workqueue: 0000:74:02.0_disco_q sas_revalidate_domain [libsas]
[ 4613.691518] Call trace:
[ 4613.694678] __switch_to+0xf8/0x17c
[ 4613.698872] __schedule+0x660/0xee0
[ 4613.703063] schedule+0xac/0x240
[ 4613.706994] schedule_timeout+0x500/0x610
[ 4613.711705] __down+0x128/0x36c
[ 4613.715548] down+0x240/0x2d0
[ 4613.719221] hisi_sas_internal_abort_timeout+0x1bc/0x260 [hisi_sas_main]
[ 4613.726618] sas_execute_internal_abort+0x144/0x310 [libsas]
[ 4613.732976] sas_execute_internal_abort_dev+0x44/0x60 [libsas]
[ 4613.739504] hisi_sas_internal_task_abort_dev.isra.0+0xbc/0x1b0 [hisi_sas_main]
[ 4613.747499] hisi_sas_dev_gone+0x174/0x250 [hisi_sas_main]
[ 4613.753682] sas_notify_lldd_dev_gone+0xec/0x2e0 [libsas]
[ 4613.759781] sas_unregister_common_dev+0x4c/0x7a0 [libsas]
[ 4613.765962] sas_destruct_devices+0xb8/0x120 [libsas]
[ 4613.771709] sas_do_revalidate_domain.constprop.0+0x1b8/0x31c [libsas]
[ 4613.778930] sas_revalidate_domain+0x60/0xa4 [libsas]
[ 4613.784716] process_one_work+0x248/0x950
[ 4613.789424] worker_thread+0x318/0x934
[ 4613.793878] kthread+0x190/0x200
[ 4613.797810] ret_from_fork+0x10/0x18
[ 4613.802121] INFO: task kworker/u256:4:316722 blocked for more than 120 seconds.
[ 4613.816026] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4613.824538] task:kworker/u256:4 state:D stack: 0 pid:316722 ppid: 2 flags:0x00000208
[ 4613.833670] Workqueue: 0000:74:02.0 hisi_sas_rst_work_handler [hisi_sas_main]
[ 4613.841491] Call trace:
[ 4613.844647] __switch_to+0xf8/0x17c
[ 4613.848852] __schedule+0x660/0xee0
[ 4613.853052] schedule+0xac/0x240
[ 4613.856984] schedule_timeout+0x500/0x610
[ 4613.861695] __down+0x128/0x36c
[ 4613.865542] down+0x240/0x2d0
[ 4613.869216] hisi_sas_controller_prereset+0x58/0x1fc [hisi_sas_main]
[ 4613.876324] hisi_sas_rst_work_handler+0x40/0x8c [hisi_sas_main]
[ 4613.883019] process_one_work+0x248/0x950
[ 4613.887732] worker_thread+0x318/0x934
[ 4613.892204] kthread+0x190/0x200
[ 4613.896118] ret_from_fork+0x10/0x18
[ 4613.900423] INFO: task kworker/u256:1:348985 blocked for more than 121 seconds.
[ 4613.914341] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4613.922852] task:kworker/u256:1 state:D stack: 0 pid:348985 ppid: 2 flags:0x00000208
[ 4613.931984] Workqueue: 0000:74:02.0_event_q sas_port_event_worker [libsas]
[ 4613.939549] Call trace:
[ 4613.942702] __switch_to+0xf8/0x17c
[ 4613.946892] __schedule+0x660/0xee0
[ 4613.951083] schedule+0xac/0x240
[ 4613.955015] schedule_timeout+0x500/0x610
[ 4613.959725] wait_for_common+0x200/0x610
[ 4613.964349] wait_for_completion+0x3c/0x5c
[ 4613.969146] flush_workqueue+0x198/0x790
[ 4613.973776] sas_porte_broadcast_rcvd+0x1e8/0x320 [libsas]
[ 4613.979960] sas_port_event_worker+0x54/0xa0 [libsas]
[ 4613.985708] process_one_work+0x248/0x950
[ 4613.990420] worker_thread+0x318/0x934
[ 4613.994868] kthread+0x190/0x200
[ 4613.998800] ret_from_fork+0x10/0x18
This is because when the device goes offline, we obtain the hisi_hba
semaphore and send the ABORT_DEV command to the device. However, the
internal abort timed out due to the 2 bit ECC error and triggers automatic
dump. In addition, since the hisi_hba semaphore has been obtained, the dump
cannot be executed and the controller cannot be reset.
Therefore, the deadlocks occur on the following circular dependencies
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_mirred: use the backlog for mirred ingress
The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog
for nested calls to mirred ingress") hangs our testing VMs every 10 or so
runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by
lockdep.
The problem as previously described by Davide (see Link) is that
if we reverse flow of traffic with the redirect (egress -> ingress)
we may reach the same socket which generated the packet. And we may
still be holding its socket lock. The common solution to such deadlocks
is to put the packet in the Rx backlog, rather than run the Rx path
inline. Do that for all egress -> ingress reversals, not just once
we started to nest mirred calls.
In the past there was a concern that the backlog indirection will
lead to loss of error reporting / less accurate stats. But the current
workaround does not seem to address the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid deadlock in fs reclaim with page writeback
Ext4 has a filesystem wide lock protecting ext4_writepages() calls to
avoid races with switching of journalled data flag or inode format. This
lock can however cause a deadlock like:
CPU0 CPU1
ext4_writepages()
percpu_down_read(sbi->s_writepages_rwsem);
ext4_change_inode_journal_flag()
percpu_down_write(sbi->s_writepages_rwsem);
- blocks, all readers block from now on
ext4_do_writepages()
ext4_init_io_end()
kmem_cache_zalloc(io_end_cachep, GFP_KERNEL)
fs_reclaim frees dentry...
dentry_unlink_inode()
iput() - last ref =>
iput_final() - inode dirty =>
write_inode_now()...
ext4_writepages() tries to acquire sbi->s_writepages_rwsem
and blocks forever
Make sure we cannot recurse into filesystem reclaim from writeback code
to avoid the deadlock. |
| In the Linux kernel, the following vulnerability has been resolved:
riscv: VMAP_STACK overflow detection thread-safe
commit 31da94c25aea ("riscv: add VMAP_STACK overflow detection") added
support for CONFIG_VMAP_STACK. If overflow is detected, CPU switches to
`shadow_stack` temporarily before switching finally to per-cpu
`overflow_stack`.
If two CPUs/harts are racing and end up in over flowing kernel stack, one
or both will end up corrupting each other state because `shadow_stack` is
not per-cpu. This patch optimizes per-cpu overflow stack switch by
directly picking per-cpu `overflow_stack` and gets rid of `shadow_stack`.
Following are the changes in this patch
- Defines an asm macro to obtain per-cpu symbols in destination
register.
- In entry.S, when overflow is detected, per-cpu overflow stack is
located using per-cpu asm macro. Computing per-cpu symbol requires
a temporary register. x31 is saved away into CSR_SCRATCH
(CSR_SCRATCH is anyways zero since we're in kernel).
Please see Links for additional relevant disccussion and alternative
solution.
Tested by `echo EXHAUST_STACK > /sys/kernel/debug/provoke-crash/DIRECT`
Kernel crash log below
Insufficient stack space to handle exception!/debug/provoke-crash/DIRECT
Task stack: [0xff20000010a98000..0xff20000010a9c000]
Overflow stack: [0xff600001f7d98370..0xff600001f7d99370]
CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34
Hardware name: riscv-virtio,qemu (DT)
epc : __memset+0x60/0xfc
ra : recursive_loop+0x48/0xc6 [lkdtm]
epc : ffffffff808de0e4 ra : ffffffff0163a752 sp : ff20000010a97e80
gp : ffffffff815c0330 tp : ff600000820ea280 t0 : ff20000010a97e88
t1 : 000000000000002e t2 : 3233206874706564 s0 : ff20000010a982b0
s1 : 0000000000000012 a0 : ff20000010a97e88 a1 : 0000000000000000
a2 : 0000000000000400 a3 : ff20000010a98288 a4 : 0000000000000000
a5 : 0000000000000000 a6 : fffffffffffe43f0 a7 : 00007fffffffffff
s2 : ff20000010a97e88 s3 : ffffffff01644680 s4 : ff20000010a9be90
s5 : ff600000842ba6c0 s6 : 00aaaaaac29e42b0 s7 : 00fffffff0aa3684
s8 : 00aaaaaac2978040 s9 : 0000000000000065 s10: 00ffffff8a7cad10
s11: 00ffffff8a76a4e0 t3 : ffffffff815dbaf4 t4 : ffffffff815dbaf4
t5 : ffffffff815dbab8 t6 : ff20000010a9bb48
status: 0000000200000120 badaddr: ff20000010a97e88 cause: 000000000000000f
Kernel panic - not syncing: Kernel stack overflow
CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80006754>] dump_backtrace+0x30/0x38
[<ffffffff808de798>] show_stack+0x40/0x4c
[<ffffffff808ea2a8>] dump_stack_lvl+0x44/0x5c
[<ffffffff808ea2d8>] dump_stack+0x18/0x20
[<ffffffff808dec06>] panic+0x126/0x2fe
[<ffffffff800065ea>] walk_stackframe+0x0/0xf0
[<ffffffff0163a752>] recursive_loop+0x48/0xc6 [lkdtm]
SMP: stopping secondary CPUs
---[ end Kernel panic - not syncing: Kernel stack overflow ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: Avoid touching renamed directory if parent does not change
The VFS will not be locking moved directory if its parent does not
change. Change ocfs2 rename code to avoid touching renamed directory if
its parent does not change as without locking that can corrupt the
filesystem. |
