| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write
A deadlock can occur between nfc_unregister_device() and rfkill_fop_write()
due to lock ordering inversion between device_lock and rfkill_global_mutex.
The problematic lock order is:
Thread A (rfkill_fop_write):
rfkill_fop_write()
mutex_lock(&rfkill_global_mutex)
rfkill_set_block()
nfc_rfkill_set_block()
nfc_dev_down()
device_lock(&dev->dev) <- waits for device_lock
Thread B (nfc_unregister_device):
nfc_unregister_device()
device_lock(&dev->dev)
rfkill_unregister()
mutex_lock(&rfkill_global_mutex) <- waits for rfkill_global_mutex
This creates a classic ABBA deadlock scenario.
Fix this by moving rfkill_unregister() and rfkill_destroy() outside the
device_lock critical section. Store the rfkill pointer in a local variable
before releasing the lock, then call rfkill_unregister() after releasing
device_lock.
This change is safe because rfkill_fop_write() holds rfkill_global_mutex
while calling the rfkill callbacks, and rfkill_unregister() also acquires
rfkill_global_mutex before cleanup. Therefore, rfkill_unregister() will
wait for any ongoing callback to complete before proceeding, and
device_del() is only called after rfkill_unregister() returns, preventing
any use-after-free.
The similar lock ordering in nfc_register_device() (device_lock ->
rfkill_global_mutex via rfkill_register) is safe because during
registration the device is not yet in rfkill_list, so no concurrent
rfkill operations can occur on this device. |
| In the Linux kernel, the following vulnerability has been resolved:
rust_binder: remove spin_lock() in rust_shrink_free_page()
When forward-porting Rust Binder to 6.18, I neglected to take commit
fb56fdf8b9a2 ("mm/list_lru: split the lock to per-cgroup scope") into
account, and apparently I did not end up running the shrinker callback
when I sanity tested the driver before submission. This leads to crashes
like the following:
============================================
WARNING: possible recursive locking detected
6.18.0-mainline-maybe-dirty #1 Tainted: G IO
--------------------------------------------
kswapd0/68 is trying to acquire lock:
ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: lock_list_lru_of_memcg+0x128/0x230
but task is already holding lock:
ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&l->lock);
lock(&l->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kswapd0/68:
#0: ffffffff90d2e260 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x597/0x1160
#1: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20
#2: ffffffff90cf3680 (rcu_read_lock){....}-{1:2}, at: lock_list_lru_of_memcg+0x2d/0x230
To fix this, remove the spin_lock() call from rust_shrink_free_page(). |
| In the Linux kernel, the following vulnerability has been resolved:
block: Remove queue freezing from several sysfs store callbacks
Freezing the request queue from inside sysfs store callbacks may cause a
deadlock in combination with the dm-multipath driver and the
queue_if_no_path option. Additionally, freezing the request queue slows
down system boot on systems where sysfs attributes are set synchronously.
Fix this by removing the blk_mq_freeze_queue() / blk_mq_unfreeze_queue()
calls from the store callbacks that do not strictly need these callbacks.
Add the __data_racy annotation to request_queue.rq_timeout to suppress
KCSAN data race reports about the rq_timeout reads.
This patch may cause a small delay in applying the new settings.
For all the attributes affected by this patch, I/O will complete
correctly whether the old or the new value of the attribute is used.
This patch affects the following sysfs attributes:
* io_poll_delay
* io_timeout
* nomerges
* read_ahead_kb
* rq_affinity
Here is an example of a deadlock triggered by running test srp/002
if this patch is not applied:
task:multipathd
Call Trace:
<TASK>
__schedule+0x8c1/0x1bf0
schedule+0xdd/0x270
schedule_preempt_disabled+0x1c/0x30
__mutex_lock+0xb89/0x1650
mutex_lock_nested+0x1f/0x30
dm_table_set_restrictions+0x823/0xdf0
__bind+0x166/0x590
dm_swap_table+0x2a7/0x490
do_resume+0x1b1/0x610
dev_suspend+0x55/0x1a0
ctl_ioctl+0x3a5/0x7e0
dm_ctl_ioctl+0x12/0x20
__x64_sys_ioctl+0x127/0x1a0
x64_sys_call+0xe2b/0x17d0
do_syscall_64+0x96/0x3a0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
task:(udev-worker)
Call Trace:
<TASK>
__schedule+0x8c1/0x1bf0
schedule+0xdd/0x270
blk_mq_freeze_queue_wait+0xf2/0x140
blk_mq_freeze_queue_nomemsave+0x23/0x30
queue_ra_store+0x14e/0x290
queue_attr_store+0x23e/0x2c0
sysfs_kf_write+0xde/0x140
kernfs_fop_write_iter+0x3b2/0x630
vfs_write+0x4fd/0x1390
ksys_write+0xfd/0x230
__x64_sys_write+0x76/0xc0
x64_sys_call+0x276/0x17d0
do_syscall_64+0x96/0x3a0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix VM hard lockup after prolonged inactivity with periodic HV timer
When advancing the target expiration for the guest's APIC timer in periodic
mode, set the expiration to "now" if the target expiration is in the past
(similar to what is done in update_target_expiration()). Blindly adding
the period to the previous target expiration can result in KVM generating
a practically unbounded number of hrtimer IRQs due to programming an
expired timer over and over. In extreme scenarios, e.g. if userspace
pauses/suspends a VM for an extended duration, this can even cause hard
lockups in the host.
Currently, the bug only affects Intel CPUs when using the hypervisor timer
(HV timer), a.k.a. the VMX preemption timer. Unlike the software timer,
a.k.a. hrtimer, which KVM keeps running even on exits to userspace, the
HV timer only runs while the guest is active. As a result, if the vCPU
does not run for an extended duration, there will be a huge gap between
the target expiration and the current time the vCPU resumes running.
Because the target expiration is incremented by only one period on each
timer expiration, this leads to a series of timer expirations occurring
rapidly after the vCPU/VM resumes.
More critically, when the vCPU first triggers a periodic HV timer
expiration after resuming, advancing the expiration by only one period
will result in a target expiration in the past. As a result, the delta
may be calculated as a negative value. When the delta is converted into
an absolute value (tscdeadline is an unsigned u64), the resulting value
can overflow what the HV timer is capable of programming. I.e. the large
value will exceed the VMX Preemption Timer's maximum bit width of
cpu_preemption_timer_multi + 32, and thus cause KVM to switch from the
HV timer to the software timer (hrtimers).
After switching to the software timer, periodic timer expiration callbacks
may be executed consecutively within a single clock interrupt handler,
because hrtimers honors KVM's request for an expiration in the past and
immediately re-invokes KVM's callback after reprogramming. And because
the interrupt handler runs with IRQs disabled, restarting KVM's hrtimer
over and over until the target expiration is advanced to "now" can result
in a hard lockup.
E.g. the following hard lockup was triggered in the host when running a
Windows VM (only relevant because it used the APIC timer in periodic mode)
after resuming the VM from a long suspend (in the host).
NMI watchdog: Watchdog detected hard LOCKUP on cpu 45
...
RIP: 0010:advance_periodic_target_expiration+0x4d/0x80 [kvm]
...
RSP: 0018:ff4f88f5d98d8ef0 EFLAGS: 00000046
RAX: fff0103f91be678e RBX: fff0103f91be678e RCX: 00843a7d9e127bcc
RDX: 0000000000000002 RSI: 0052ca4003697505 RDI: ff440d5bfbdbd500
RBP: ff440d5956f99200 R08: ff2ff2a42deb6a84 R09: 000000000002a6c0
R10: 0122d794016332b3 R11: 0000000000000000 R12: ff440db1af39cfc0
R13: ff440db1af39cfc0 R14: ffffffffc0d4a560 R15: ff440db1af39d0f8
FS: 00007f04a6ffd700(0000) GS:ff440db1af380000(0000) knlGS:000000e38a3b8000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000d5651feff8 CR3: 000000684e038002 CR4: 0000000000773ee0
PKRU: 55555554
Call Trace:
<IRQ>
apic_timer_fn+0x31/0x50 [kvm]
__hrtimer_run_queues+0x100/0x280
hrtimer_interrupt+0x100/0x210
? ttwu_do_wakeup+0x19/0x160
smp_apic_timer_interrupt+0x6a/0x130
apic_timer_interrupt+0xf/0x20
</IRQ>
Moreover, if the suspend duration of the virtual machine is not long enough
to trigger a hard lockup in this scenario, since commit 98c25ead5eda
("KVM: VMX: Move preemption timer <=> hrtimer dance to common x86"), KVM
will continue using the software timer until the guest reprograms the APIC
timer in some way. Since the periodic timer does not require frequent APIC
timer register programming, the guest may continue to use the software
timer in
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: avoid deadlock on fallback while reinjecting
Jakub reported an MPTCP deadlock at fallback time:
WARNING: possible recursive locking detected
6.18.0-rc7-virtme #1 Not tainted
--------------------------------------------
mptcp_connect/20858 is trying to acquire lock:
ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280
but task is already holding lock:
ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&msk->fallback_lock);
lock(&msk->fallback_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by mptcp_connect/20858:
#0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0
#1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0
#2: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0
stack backtrace:
CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full)
Hardware name: Bochs, BIOS Bochs 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xa0
print_deadlock_bug.cold+0xc0/0xcd
validate_chain+0x2ff/0x5f0
__lock_acquire+0x34c/0x740
lock_acquire.part.0+0xbc/0x260
_raw_spin_lock_bh+0x38/0x50
__mptcp_try_fallback+0xd8/0x280
mptcp_sendmsg_frag+0x16c2/0x3050
__mptcp_retrans+0x421/0xaa0
mptcp_release_cb+0x5aa/0xa70
release_sock+0xab/0x1d0
mptcp_sendmsg+0xd5b/0x1bc0
sock_write_iter+0x281/0x4d0
new_sync_write+0x3c5/0x6f0
vfs_write+0x65e/0xbb0
ksys_write+0x17e/0x200
do_syscall_64+0xbb/0xfd0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7fa5627cbc5e
Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa
RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e
RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005
RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920
R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c
The packet scheduler could attempt a reinjection after receiving an
MP_FAIL and before the infinite map has been transmitted, causing a
deadlock since MPTCP needs to do the reinjection atomically from WRT
fallback.
Address the issue explicitly avoiding the reinjection in the critical
scenario. Note that this is the only fallback critical section that
could potentially send packets and hit the double-lock. |
| Spring MVC and WebFlux applications are vulnerable to stream corruption when using Server-Sent Events (SSE). This issue affects Spring Foundation: from 7.0.0 through 7.0.5, from 6.2.0 through 6.2.16, from 6.1.0 through 6.1.25, from 5.3.0 through 5.3.46. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not strictly require dirty metadata threshold for metadata writepages
[BUG]
There is an internal report that over 1000 processes are
waiting at the io_schedule_timeout() of balance_dirty_pages(), causing
a system hang and trigger a kernel coredump.
The kernel is v6.4 kernel based, but the root problem still applies to
any upstream kernel before v6.18.
[CAUSE]
From Jan Kara for his wisdom on the dirty page balance behavior first.
This cgroup dirty limit was what was actually playing the role here
because the cgroup had only a small amount of memory and so the dirty
limit for it was something like 16MB.
Dirty throttling is responsible for enforcing that nobody can dirty
(significantly) more dirty memory than there's dirty limit. Thus when
a task is dirtying pages it periodically enters into balance_dirty_pages()
and we let it sleep there to slow down the dirtying.
When the system is over dirty limit already (either globally or within
a cgroup of the running task), we will not let the task exit from
balance_dirty_pages() until the number of dirty pages drops below the
limit.
So in this particular case, as I already mentioned, there was a cgroup
with relatively small amount of memory and as a result with dirty limit
set at 16MB. A task from that cgroup has dirtied about 28MB worth of
pages in btrfs btree inode and these were practically the only dirty
pages in that cgroup.
So that means the only way to reduce the dirty pages of that cgroup is
to writeback the dirty pages of btrfs btree inode, and only after that
those processes can exit balance_dirty_pages().
Now back to the btrfs part, btree_writepages() is responsible for
writing back dirty btree inode pages.
The problem here is, there is a btrfs internal threshold that if the
btree inode's dirty bytes are below the 32M threshold, it will not
do any writeback.
This behavior is to batch as much metadata as possible so we won't write
back those tree blocks and then later re-COW them again for another
modification.
This internal 32MiB is higher than the existing dirty page size (28MiB),
meaning no writeback will happen, causing a deadlock between btrfs and
cgroup:
- Btrfs doesn't want to write back btree inode until more dirty pages
- Cgroup/MM doesn't want more dirty pages for btrfs btree inode
Thus any process touching that btree inode is put into sleep until
the number of dirty pages is reduced.
Thanks Jan Kara a lot for the analysis of the root cause.
[ENHANCEMENT]
Since kernel commit b55102826d7d ("btrfs: set AS_KERNEL_FILE on the
btree_inode"), btrfs btree inode pages will only be charged to the root
cgroup which should have a much larger limit than btrfs' 32MiB
threshold.
So it should not affect newer kernels.
But for all current LTS kernels, they are all affected by this problem,
and backporting the whole AS_KERNEL_FILE may not be a good idea.
Even for newer kernels I still think it's a good idea to get
rid of the internal threshold at btree_writepages(), since for most cases
cgroup/MM has a better view of full system memory usage than btrfs' fixed
threshold.
For internal callers using btrfs_btree_balance_dirty() since that
function is already doing internal threshold check, we don't need to
bother them.
But for external callers of btree_writepages(), just respect their
requests and write back whatever they want, ignoring the internal
btrfs threshold to avoid such deadlock on btree inode dirty page
balancing. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: Rework long task execution when adding/deleting entries
When adding/deleting large number of elements in one step in ipset, it can
take a reasonable amount of time and can result in soft lockup errors. The
patch 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of
consecutive elements to add/delete") tried to fix it by limiting the max
elements to process at all. However it was not enough, it is still possible
that we get hung tasks. Lowering the limit is not reasonable, so the
approach in this patch is as follows: rely on the method used at resizing
sets and save the state when we reach a smaller internal batch limit,
unlock/lock and proceed from the saved state. Thus we can avoid long
continuous tasks and at the same time removed the limit to add/delete large
number of elements in one step.
The nfnl mutex is held during the whole operation which prevents one to
issue other ipset commands in parallel. |
| In the Linux kernel, the following vulnerability has been resolved:
USB: Gadget: core: Help prevent panic during UVC unconfigure
Avichal Rakesh reported a kernel panic that occurred when the UVC
gadget driver was removed from a gadget's configuration. The panic
involves a somewhat complicated interaction between the kernel driver
and a userspace component (as described in the Link tag below), but
the analysis did make one thing clear: The Gadget core should
accomodate gadget drivers calling usb_gadget_deactivate() as part of
their unbind procedure.
Currently this doesn't work. gadget_unbind_driver() calls
driver->unbind() while holding the udc->connect_lock mutex, and
usb_gadget_deactivate() attempts to acquire that mutex, which will
result in a deadlock.
The simple fix is for gadget_unbind_driver() to release the mutex when
invoking the ->unbind() callback. There is no particular reason for
it to be holding the mutex at that time, and the mutex isn't held
while the ->bind() callback is invoked. So we'll drop the mutex
before performing the unbind callback and reacquire it afterward.
We'll also add a couple of comments to usb_gadget_activate() and
usb_gadget_deactivate(). Because they run in process context they
must not be called from a gadget driver's ->disconnect() callback,
which (according to the kerneldoc for struct usb_gadget_driver in
include/linux/usb/gadget.h) may run in interrupt context. This may
help prevent similar bugs from arising in the future. |
| A memory corruption issue was addressed with improved lock state checking. This issue is fixed in watchOS 26.1, iOS 18.7.2 and iPadOS 18.7.2, macOS Tahoe 26.1, visionOS 26.1, tvOS 26.1, macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, iOS 26.1 and iPadOS 26.1. A malicious application may cause unexpected changes in memory shared between processes. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix deadlock in tc route query code
Cited commit causes ABBA deadlock[0] when peer flows are created while
holding the devcom rw semaphore. Due to peer flows offload implementation
the lock is taken much higher up the call chain and there is no obvious way
to easily fix the deadlock. Instead, since tc route query code needs the
peer eswitch structure only to perform a lookup in xarray and doesn't
perform any sleeping operations with it, refactor the code for lockless
execution in following ways:
- RCUify the devcom 'data' pointer. When resetting the pointer
synchronously wait for RCU grace period before returning. This is fine
since devcom is currently only used for synchronization of
pairing/unpairing of eswitches which is rare and already expensive as-is.
- Wrap all usages of 'paired' boolean in {READ|WRITE}_ONCE(). The flag has
already been used in some unlocked contexts without proper
annotations (e.g. users of mlx5_devcom_is_paired() function), but it wasn't
an issue since all relevant code paths checked it again after obtaining the
devcom semaphore. Now it is also used by mlx5_devcom_get_peer_data_rcu() as
"best effort" check to return NULL when devcom is being unpaired. Note that
while RCU read lock doesn't prevent the unpaired flag from being changed
concurrently it still guarantees that reader can continue to use 'data'.
- Refactor mlx5e_tc_query_route_vport() function to use new
mlx5_devcom_get_peer_data_rcu() API which fixes the deadlock.
[0]:
[ 164.599612] ======================================================
[ 164.600142] WARNING: possible circular locking dependency detected
[ 164.600667] 6.3.0-rc3+ #1 Not tainted
[ 164.601021] ------------------------------------------------------
[ 164.601557] handler1/3456 is trying to acquire lock:
[ 164.601998] ffff88811f1714b0 (&esw->offloads.encap_tbl_lock){+.+.}-{3:3}, at: mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.603078]
but task is already holding lock:
[ 164.603617] ffff88810137fc98 (&comp->sem){++++}-{3:3}, at: mlx5_devcom_get_peer_data+0x37/0x80 [mlx5_core]
[ 164.604459]
which lock already depends on the new lock.
[ 164.605190]
the existing dependency chain (in reverse order) is:
[ 164.605848]
-> #1 (&comp->sem){++++}-{3:3}:
[ 164.606380] down_read+0x39/0x50
[ 164.606772] mlx5_devcom_get_peer_data+0x37/0x80 [mlx5_core]
[ 164.607336] mlx5e_tc_query_route_vport+0x86/0xc0 [mlx5_core]
[ 164.607914] mlx5e_tc_tun_route_lookup+0x1a4/0x1d0 [mlx5_core]
[ 164.608495] mlx5e_attach_decap_route+0xc6/0x1e0 [mlx5_core]
[ 164.609063] mlx5e_tc_add_fdb_flow+0x1ea/0x360 [mlx5_core]
[ 164.609627] __mlx5e_add_fdb_flow+0x2d2/0x430 [mlx5_core]
[ 164.610175] mlx5e_configure_flower+0x952/0x1a20 [mlx5_core]
[ 164.610741] tc_setup_cb_add+0xd4/0x200
[ 164.611146] fl_hw_replace_filter+0x14c/0x1f0 [cls_flower]
[ 164.611661] fl_change+0xc95/0x18a0 [cls_flower]
[ 164.612116] tc_new_tfilter+0x3fc/0xd20
[ 164.612516] rtnetlink_rcv_msg+0x418/0x5b0
[ 164.612936] netlink_rcv_skb+0x54/0x100
[ 164.613339] netlink_unicast+0x190/0x250
[ 164.613746] netlink_sendmsg+0x245/0x4a0
[ 164.614150] sock_sendmsg+0x38/0x60
[ 164.614522] ____sys_sendmsg+0x1d0/0x1e0
[ 164.614934] ___sys_sendmsg+0x80/0xc0
[ 164.615320] __sys_sendmsg+0x51/0x90
[ 164.615701] do_syscall_64+0x3d/0x90
[ 164.616083] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 164.616568]
-> #0 (&esw->offloads.encap_tbl_lock){+.+.}-{3:3}:
[ 164.617210] __lock_acquire+0x159e/0x26e0
[ 164.617638] lock_acquire+0xc2/0x2a0
[ 164.618018] __mutex_lock+0x92/0xcd0
[ 164.618401] mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.618943] post_process_attr+0x153/0x2d0 [
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop
With this refcnt added in sctp_stream_priorities, we don't need to
traverse all streams to check if the prio is used by other streams
when freeing one stream's prio in sctp_sched_prio_free_sid(). This
can avoid a nested loop (up to 65535 * 65535), which may cause a
stuck as Ying reported:
watchdog: BUG: soft lockup - CPU#23 stuck for 26s! [ksoftirqd/23:136]
Call Trace:
<TASK>
sctp_sched_prio_free_sid+0xab/0x100 [sctp]
sctp_stream_free_ext+0x64/0xa0 [sctp]
sctp_stream_free+0x31/0x50 [sctp]
sctp_association_free+0xa5/0x200 [sctp]
Note that it doesn't need to use refcount_t type for this counter,
as its accessing is always protected under the sock lock.
v1->v2:
- add a check in sctp_sched_prio_set to avoid the possible prio_head
refcnt overflow. |
| In the Linux kernel, the following vulnerability has been resolved:
ipvlan: Make the addrs_lock be per port
Make the addrs_lock be per port, not per ipvlan dev.
Initial code seems to be written in the assumption,
that any address change must occur under RTNL.
But it is not so for the case of IPv6. So
1) Introduce per-port addrs_lock.
2) It was needed to fix places where it was forgotten
to take lock (ipvlan_open/ipvlan_close)
This appears to be a very minor problem though.
Since it's highly unlikely that ipvlan_add_addr() will
be called on 2 CPU simultaneously. But nevertheless,
this could cause:
1) False-negative of ipvlan_addr_busy(): one interface
iterated through all port->ipvlans + ipvlan->addrs
under some ipvlan spinlock, and another added IP
under its own lock. Though this is only possible
for IPv6, since looks like only ipvlan_addr6_event() can be
called without rtnl_lock.
2) Race since ipvlan_ht_addr_add(port) is called under
different ipvlan->addrs_lock locks
This should not affect performance, since add/remove IP
is a rare situation and spinlock is not taken on fast
paths. |
| In the Linux kernel, the following vulnerability has been resolved:
net: usb: r8152: fix resume reset deadlock
rtl8152 can trigger device reset during reset which
potentially can result in a deadlock:
**** DPM device timeout after 10 seconds; 15 seconds until panic ****
Call Trace:
<TASK>
schedule+0x483/0x1370
schedule_preempt_disabled+0x15/0x30
__mutex_lock_common+0x1fd/0x470
__rtl8152_set_mac_address+0x80/0x1f0
dev_set_mac_address+0x7f/0x150
rtl8152_post_reset+0x72/0x150
usb_reset_device+0x1d0/0x220
rtl8152_resume+0x99/0xc0
usb_resume_interface+0x3e/0xc0
usb_resume_both+0x104/0x150
usb_resume+0x22/0x110
The problem is that rtl8152 resume calls reset under
tp->control mutex while reset basically re-enters rtl8152
and attempts to acquire the same tp->control lock once
again.
Reset INACCESSIBLE device outside of tp->control mutex
scope to avoid recursive mutex_lock() deadlock. |
| In the Linux kernel, the following vulnerability has been resolved:
procfs: avoid fetching build ID while holding VMA lock
Fix PROCMAP_QUERY to fetch optional build ID only after dropping mmap_lock
or per-VMA lock, whichever was used to lock VMA under question, to avoid
deadlock reported by syzbot:
-> #1 (&mm->mmap_lock){++++}-{4:4}:
__might_fault+0xed/0x170
_copy_to_iter+0x118/0x1720
copy_page_to_iter+0x12d/0x1e0
filemap_read+0x720/0x10a0
blkdev_read_iter+0x2b5/0x4e0
vfs_read+0x7f4/0xae0
ksys_read+0x12a/0x250
do_syscall_64+0xcb/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&sb->s_type->i_mutex_key#8){++++}-{4:4}:
__lock_acquire+0x1509/0x26d0
lock_acquire+0x185/0x340
down_read+0x98/0x490
blkdev_read_iter+0x2a7/0x4e0
__kernel_read+0x39a/0xa90
freader_fetch+0x1d5/0xa80
__build_id_parse.isra.0+0xea/0x6a0
do_procmap_query+0xd75/0x1050
procfs_procmap_ioctl+0x7a/0xb0
__x64_sys_ioctl+0x18e/0x210
do_syscall_64+0xcb/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&mm->mmap_lock);
lock(&sb->s_type->i_mutex_key#8);
lock(&mm->mmap_lock);
rlock(&sb->s_type->i_mutex_key#8);
*** DEADLOCK ***
This seems to be exacerbated (as we haven't seen these syzbot reports
before that) by the recent:
777a8560fd29 ("lib/buildid: use __kernel_read() for sleepable context")
To make this safe, we need to grab file refcount while VMA is still locked, but
other than that everything is pretty straightforward. Internal build_id_parse()
API assumes VMA is passed, but it only needs the underlying file reference, so
just add another variant build_id_parse_file() that expects file passed
directly.
[akpm@linux-foundation.org: fix up kerneldoc] |
| In the Linux kernel, the following vulnerability has been resolved:
riscv: trace: fix snapshot deadlock with sbi ecall
If sbi_ecall.c's functions are traceable,
echo "__sbi_ecall:snapshot" > /sys/kernel/tracing/set_ftrace_filter
may get the kernel into a deadlock.
(Functions in sbi_ecall.c are excluded from tracing if
CONFIG_RISCV_ALTERNATIVE_EARLY is set.)
__sbi_ecall triggers a snapshot of the ringbuffer. The snapshot code
raises an IPI interrupt, which results in another call to __sbi_ecall
and another snapshot...
All it takes to get into this endless loop is one initial __sbi_ecall.
On RISC-V systems without SSTC extension, the clock events in
timer-riscv.c issue periodic sbi ecalls, making the problem easy to
trigger.
Always exclude the sbi_ecall.c functions from tracing to fix the
potential deadlock.
sbi ecalls can easiliy be logged via trace events, excluding ecall
functions from function tracing is not a big limitation. |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify()
The acpi_power_meter driver's .notify() callback function,
acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock
that is also acquired by callbacks in sysfs attributes of the device
being unregistered which is prone to deadlocks between sysfs access and
device removal.
Address this by moving the hwmon device removal in
acpi_power_meter_notify() outside the lock in question, but notice
that doing it alone is not sufficient because two concurrent
METER_NOTIFY_CONFIG notifications may be attempting to remove the
same device at the same time. To prevent that from happening, add a
new lock serializing the execution of the switch () statement in
acpi_power_meter_notify(). For simplicity, it is a static mutex
which should not be a problem from the performance perspective.
The new lock also allows the hwmon_device_register_with_info()
in acpi_power_meter_notify() to be called outside the inner lock
because it prevents the other notifications handled by that function
from manipulating the "resource" object while the hwmon device based
on it is being registered. The sending of ACPI netlink messages from
acpi_power_meter_notify() is serialized by the new lock too which
generally helps to ensure that the order of handling firmware
notifications is the same as the order of sending netlink messages
related to them.
In addition, notice that hwmon_device_register_with_info() may fail
in which case resource->hwmon_dev will become an error pointer,
so add checks to avoid attempting to unregister the hwmon device
pointer to by it in that case to acpi_power_meter_notify() and
acpi_power_meter_remove(). |
| In the Linux kernel, the following vulnerability has been resolved:
sfc: fix deadlock in RSS config read
Since cited commit, core locks the net_device's rss_lock when handling
ethtool -x command, so driver's implementation should not lock it
again. Remove the latter. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "f2fs: block cache/dio write during f2fs_enable_checkpoint()"
This reverts commit 196c81fdd438f7ac429d5639090a9816abb9760a.
Original patch may cause below deadlock, revert it.
write remount
- write_begin
- lock_page --- lock A
- prepare_write_begin
- f2fs_map_lock
- f2fs_enable_checkpoint
- down_write(cp_enable_rwsem) --- lock B
- sync_inode_sb
- writepages
- lock_page --- lock A
- down_read(cp_enable_rwsem) --- lock A |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix dead lock while flushing management frames
Commit [1] converted the management transmission work item into a
wiphy work. Since a wiphy work can only run under wiphy lock
protection, a race condition happens in below scenario:
1. a management frame is queued for transmission.
2. ath12k_mac_op_flush() gets called to flush pending frames associated
with the hardware (i.e, vif being NULL). Then in ath12k_mac_flush()
the process waits for the transmission done.
3. Since wiphy lock has been taken by the flush process, the transmission
work item has no chance to run, hence the dead lock.
>From user view, this dead lock results in below issue:
wlp8s0: authenticate with xxxxxx (local address=xxxxxx)
wlp8s0: send auth to xxxxxx (try 1/3)
wlp8s0: authenticate with xxxxxx (local address=xxxxxx)
wlp8s0: send auth to xxxxxx (try 1/3)
wlp8s0: authenticated
wlp8s0: associate with xxxxxx (try 1/3)
wlp8s0: aborting association with xxxxxx by local choice (Reason: 3=DEAUTH_LEAVING)
ath12k_pci 0000:08:00.0: failed to flush mgmt transmit queue, mgmt pkts pending 1
The dead lock can be avoided by invoking wiphy_work_flush() to proactively
run the queued work item. Note actually it is already present in
ath12k_mac_op_flush(), however it does not protect the case where vif
being NULL. Hence move it ahead to cover this case as well.
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3 |
