| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
migrate_pages_batch() unmaps each folio before moving it, and every
unmap runs the mmu_notifier invalidate callbacks. On KVM hosts
try_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() ->
tdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps
the CPU busy for a long time.
The loop already calls cond_resched(), but on PREEMPTION kernels that is
a no-op, and involuntary preemption is not a Tasks-RCU quiescent state.
A long batch therefore never reports a quiescent state, and the
migrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the
Tasks-RCU grace period for minutes, which is common at Meta fleet:
INFO: rcu_tasks detected stalls on tasks:
0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0 state:R running task
Call Trace:
tdp_mmu_zap_leafs
tdp_mmu_next_root
gfn_to_pfn_cache_invalidate_start
kvm_mmu_notifier_invalidate_range_start
__mmu_notifier_invalidate_range_start
try_to_migrate_one
try_to_migrate
migrate_pages_batch
migrate_pages
compact_zone
compact_node
kcompactd
kthread
Use cond_resched_tasks_rcu_qs() so a quiescent state is reported even
when cond_resched() does nothing.
This has also been discussed at [1] |
| In the Linux kernel, the following vulnerability has been resolved:
mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec()
I am seeing some rcu_tasks stalls in the Meta fleet during reclaim.
INFO: rcu_tasks detected stalls on tasks:
0000000088620d09: .. nvcsw: 6735/6735 holdout: 1 idle_cpu: -1/8
task:GlobalCPUThread state:R running task pid:2552016 tgid:2524552
Call Trace:
shrink_lruvec
mem_cgroup_iter
shrink_node
do_try_to_free_pages
try_to_free_pages
__alloc_frozen_pages_noprof
alloc_pages_noprof
pte_alloc_one
__pte_alloc
handle_mm_fault
Nothing promises direct reclaim returns in bounded time, and the scan loop
in shrink_lruvec() only calls cond_resched(), which is a no-op on
PREEMPTION kernels. Involuntary preemption is not a Tasks-RCU quiescent
state, so the reclaiming task never reports one and becomes a holdout.
Upgrade it to cond_resched_tasks_rcu_qs(), which reports a quiescent state
even when cond_resched() does nothing.
PS: This has been discussed in [1] |
| In the Linux kernel, the following vulnerability has been resolved:
ext2: Fix lost inode updates for IS_SYNC inodes
ext2_setsize() and ext2_xattr_set2() had a construct like:
if (IS_SYNC(inode)) {
sync_inode_metadata(inode, 1);
} else {
mark_inode_dirty(inode);
}
which leads to lost inode updates for IS_SYNC inodes because
sync_inode_metadata() does anything only if the inode is already dirty
and hence inode updates may be simply lost. Fix the problem by
unconditionally marking the inode dirty and *then* call
sync_inode_metadata(). |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: ssd1307fb: defer I2C transfers from damage callbacks
The fbdev damage callbacks may run from fbcon while printk has disabled
preemption. They currently update the display synchronously, which enters
the sleeping I2C transfer path from atomic context.
A complete report from an RK3566 system follows:
[ 258.129004] watchdog: watchdog0: watchdog did not stop!
[ 258.129067] BUG: scheduling while atomic: systemd/1/0x00000003
[ 258.129076] Modules linked in: algif_hash algif_skcipher af_alg bnep
binfmt_misc lz4hc lz4 zram snd_soc_hdmi_codec brcmfmac_wcc hci_uart
fb_ssd1306(C) fbtft(C) btqca btrtl btintel btsdio snd_soc_simple_card
motorcomm pwm_fan snd_soc_simple_card_utils ssd130x_spi nls_iso8859_1
ssd130x btbcm drm_shmem_helper display_connector brcmfmac ssd1307fb
brcmutil bluetooth cfg80211 rfkill snd_soc_rockchip_i2s_tdm
snd_soc_rk817 hantro_vpu snd_soc_core snd_compress snd_pcm_dmaengine
v4l2_vp9 snd_pcm v4l2_h264 rockchip_rga snd_timer rk_crypto2
spi_rockchip_sfc videobuf2_dma_contig snd sm3_generic v4l2_mem2mem
videobuf2_dma_sg dwmac_rk sm3 soundcore videobuf2_memops videobuf2_v4l2
stmmac_platform dw_hdmi_cec videodev videobuf2_common dw_hdmi_i2s_audio
stmmac rk817_charger pcs_xpcs mc cpufreq_dt sch_fq_codel ip_tables
x_tables autofs4
[ 258.129215] Preemption disabled at:
[ 258.129216] [<ffff80008012f96c>] vprintk_emit+0x11c/0x340
[ 258.129234] CPU: 0 PID: 1 Comm: systemd Tainted: G C
6.6.0-rc5-rockchip-rk356x #4
[ 258.129239] Hardware name: Rockchip RK3566 OPi 3B (DT)
[ 258.129243] Call trace:
[ 258.129245] dump_backtrace+0xa0/0x128
[ 258.129252] show_stack+0x20/0x38
[ 258.129256] dump_stack_lvl+0x60/0xb0
[ 258.129265] dump_stack+0x18/0x28
[ 258.129269] __schedule_bug+0xa0/0xc8
[ 258.129274] __schedule+0x9ac/0xd30
[ 258.129279] schedule+0x60/0x100
[ 258.129282] schedule_timeout+0x194/0x338
[ 258.129289] rk3x_i2c_xfer_common.isra.0+0x384/0x498
[ 258.129296] rk3x_i2c_xfer+0x20/0x60
[ 258.129300] __i2c_transfer+0x194/0x648
[ 258.129308] i2c_transfer+0x9c/0x130
[ 258.129313] i2c_transfer_buffer_flags+0x64/0x98
[ 258.129318] ssd1307fb_update_rect+0x42c/0x560 [ssd1307fb]
[ 258.129334] ssd1307fb_defio_imageblit+0x34/0x50 [ssd1307fb]
[ 258.129343] soft_cursor+0x13c/0x210
[ 258.129350] bit_cursor+0x2dc/0x550
[ 258.129354] fbcon_cursor+0xec/0x108
[ 258.129359] hide_cursor+0x44/0xc8
[ 258.129365] vt_console_print+0x398/0x3b0
[ 258.129370] console_flush_all.isra.0+0x17c/0x410
[ 258.129377] console_unlock+0x4c/0x100
[ 258.129382] vprintk_emit+0x1c8/0x340
[ 258.129386] vprintk_default+0x40/0x58
[ 258.129389] vprintk+0xb8/0xd0
[ 258.129392] _printk+0x68/0x98
[ 258.129398] watchdog_release+0x170/0x230
[ 258.129404] __fput+0xbc/0x288
[ 258.129409] __fput_sync+0x58/0x70
[ 258.129413] __arm64_sys_close+0x40/0x90
[ 258.129419] invoke_syscall+0x4c/0x118
[ 258.129426] el0_svc_common.constprop.0+0x48/0xf0
[ 258.129432] do_el0_svc+0x24/0x38
[ 258.129437] el0_svc+0x48/0x100
[ 258.129443] el0t_64_sync_handler+0xc0/0xc8
[ 258.129448] el0t_64_sync+0x190/0x198
[ 258.573087] ------------[ cut here ]------------
[ 258.573098] DEBUG_LOCKS_WARN_ON(val > preempt_count())
[ 258.573111] WARNING: CPU: 0 PID: 1 at kernel/sched/core.c:5871
preempt_count_sub+0x9c/0x148
[ 258.573130] Modules linked in: algif_hash algif_skcipher af_alg bnep
binfmt_misc lz4hc lz4 zram snd_soc_hdmi_codec brcmfmac_wcc hci_uart
fb_ssd1306(C) fbtft(C) btqca btrtl btintel btsdio snd_soc_simple_card
motorcomm pwm_fan snd_soc_simple_card_utils ssd130x_spi nls_iso8859_1
ssd130x btbcm drm_shmem_helper display_connector brcmfmac ssd1307fb
brcmutil bluetooth cfg80211 rfkill snd_soc_rockchip_i2s_tdm
snd_soc_rk817 hantro_vpu snd_soc_core snd_compress snd_pcm_dmaengine
v4l2_vp
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: max17040: synchronize work cancellation on suspend
max17040_work() requeues itself after every poll. cancel_delayed_work()
only cancels a pending instance and does not wait for a callback that is
already running.
If system suspend races with the polling callback, the callback can
continue accessing the fuel gauge and requeue itself after the suspend
callback returns.
Use cancel_delayed_work_sync() to ensure polling is quiesced before
suspend completes. |
| In the Linux kernel, the following vulnerability has been resolved:
net: ipa: fix stalled modem TX queue after runtime resume
ipa_start_xmit() unconditionally stops the TX queue before calling
pm_runtime_get(), relying on the wake scheduled by runtime resume
(ipa_modem_wake_queue_work()) to restart it once power is ACTIVE.
But that work is queued from within the runtime resume callback,
before the device's power state reaches RPM_ACTIVE, so it can run
while the device is still RPM_RESUMING. The wake is then consumed
too early: the transmit it restarts stops the queue again,
pm_runtime_get() returns -EINPROGRESS without arranging any future
wake (deferred_resume exists only for RPM_SUSPENDING), and after the
resume completes nothing is left to wake the queue. Transmit stalls
permanently: packets pile up in the qdisc behind the stopped queue,
the device runtime-suspends, and since the netdev registers no
ndo_tx_timeout the watchdog never fires. Observed on SM7635
(Fairphone 6) as the cellular data path going permanently deaf
within hours, RX included, since nothing resumes the suspended
endpoints.
Close the window by making the wake work wait for the resume to
complete (pm_runtime_get_sync()) before waking the queue. Every
queue stop is then guaranteed a later wake that happens while power
is ACTIVE; a transmit racing a new suspend/resume cycle re-schedules
the work. If the device could not be resumed, wake the queue anyway
so pending packets are dropped by the transmit path rather than
stranded.
The STARTED power flag used to narrow this window: a wake running
before the transmit path's stop suppressed that stop, but only once,
as the flag was cleared by the first stop it absorbed. Removing the
flag made a single transmit during an in-flight resume sufficient to
strand the queue, which is the form observed.
With an accelerated reproducer (autosuspend delay shortened to 5 ms,
~20 packets/s of TX), an unpatched kernel stalled three times in
230 s / 4380 packets; with this patch the same test ran 3601 s /
70298 packets without a stall. |
| In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: don't touch shared zerocopy state in skb_tx_error()
skb_tx_error() completes the zerocopy uarg and clears
SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears
SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone
shares, while the caller only owns the reference it is about to drop.
Through a clone it tells the producer its pages are free and drops
SKBFL_SHARED_FRAG for an skb that is still in flight.
Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC:
clone_execute() sends a skb_clone() into ovs_dp_process_packet() while
do_execute_actions() keeps forwarding the original, and skb_clone()
does not privatise the frags here -- skb_orphan_frags() returns early
on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker
from the packet still being forwarded, and a later local ESP delivery
decrypts in place over frags it does not own privately.
Skip it for a cloned skb. Nothing is lost: skb_release_data() clears
the zerocopy state once the last reference to the shared data goes. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: call sk_data_ready() after listener migration
When inet_csk_listen_stop() migrates an established child socket from
a closing listener to another socket in the same SO_REUSEPORT group,
the target listener gets a new accept-queue entry via
inet_csk_reqsk_queue_add(), but that path never notifies the target
listener's waiters. A nonblocking accept() still works because it
checks the queue directly, but poll()/epoll_wait() waiters and
blocking accept() callers can also remain asleep indefinitely.
Call READ_ONCE(nsk->sk_data_ready)(nsk) after a successful migration
in inet_csk_listen_stop().
However, after inet_csk_reqsk_queue_add() succeeds, the ref acquired
in reuseport_migrate_sock() is effectively transferred to
nreq->rsk_listener. Another CPU can then dequeue nreq via accept()
or listener shutdown, hit reqsk_put(), and drop that listener ref.
Since listeners are SOCK_RCU_FREE, wrap the post-queue_add()
dereferences of nsk in rcu_read_lock()/rcu_read_unlock(), which also
covers the existing sock_net(nsk) access in that path.
The reqsk_timer_handler() path does not need the same changes for two
reasons: half-open requests become readable only after the final ACK,
where tcp_child_process() already wakes the listener; and once nreq is
visible via inet_ehash_insert(), the success path no longer touches
nsk directly. |
| In the Linux kernel, the following vulnerability has been resolved:
ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS
Blamed commits forgot that vxlan/geneve use udp_tunnel[6]_xmit_skb() which
call iptunnel_xmit_stats().
iptunnel_xmit_stats() was assuming tunnels were only using
NETDEV_PCPU_STAT_TSTATS.
@syncp offset in pcpu_sw_netstats and pcpu_dstats is different.
32bit kernels would either have corruptions or freezes if the syncp
sequence was overwritten.
This patch also moves pcpu_stat_type closer to dev->{t,d}stats to avoid
a potential cache line miss since iptunnel_xmit_stats() needs to read it. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Allow LPM map access from sleepable BPF programs
trie_lookup_elem() annotates its rcu_dereference_check() walks with
only rcu_read_lock_bh_held(). Because rcu_dereference_check(p, c)
resolves to "c || rcu_read_lock_held()", this passes for XDP/NAPI and
classic RCU readers but fails for sleepable BPF programs, which enter
via __bpf_prog_enter_sleepable() and hold only rcu_read_lock_trace().
trie_update_elem() and trie_delete_elem() have the same problem in a
different form: they walk the trie with plain rcu_dereference(), which
asserts rcu_read_lock_held() unconditionally. Both are reachable from
sleepable BPF programs via the bpf_map_update_elem / bpf_map_delete_elem
helpers, and from the syscall path under classic rcu_read_lock(). In
the writer paths the trie is actually protected by trie->lock (an
rqspinlock taken across the walk); we never relied on the RCU read-side
lock to keep nodes alive there.
A sleepable LSM hook that ends up touching an LPM trie therefore
triggers lockdep on debug kernels:
=============================
WARNING: suspicious RCU usage
7.1.0-... Tainted: G E
-----------------------------
kernel/bpf/lpm_trie.c:249 suspicious rcu_dereference_check() usage!
1 lock held by net_tests/540:
#0: (rcu_tasks_trace_srcu_struct){....}-{0:0},
at: __bpf_prog_enter_sleepable+0x26/0x280
Call Trace:
dump_stack_lvl
lockdep_rcu_suspicious
trie_lookup_elem
bpf_prog_..._enforce_security_socket_connect
bpf_trampoline_...
security_socket_connect
__sys_connect
do_syscall_64
This is lockdep-only -- no UAF, since Tasks Trace RCU does serialize
against the trie's reclaim path -- but it spams the console once per
distinct callsite on every debug kernel running a sleepable BPF LSM
that touches an LPM trie, which is increasingly common.
For the lookup path, switch the rcu_dereference_check() annotation
from rcu_read_lock_bh_held() to bpf_rcu_lock_held(), which accepts all
three contexts (classic, BH, Tasks Trace). Other map types already
follow this convention.
For trie_update_elem() and trie_delete_elem(), annotate the walks as
rcu_dereference_protected(*p, 1) -- matching trie_free() in the same
file -- since trie->lock is held across the walk. rqspinlock has no
lockdep_map, so the predicate degenerates to '1' rather than
lockdep_is_held(&trie->lock); the protection is real but not
machine-verifiable. trie_get_next_key() also uses bare
rcu_dereference() but is reachable only from the BPF syscall, which
holds classic rcu_read_lock() before dispatching, so it is left
untouched. |
| When an IntegrationFlow uses .fluxTransform() with an asynchronous/reordering fluxFunction that emits raw payloads, concurrent requests on the same FluxMessageChannel subscription have their reply headers (replyChannel, errorChannel, correlationId, any propagated security/tenant headers) copied from whichever message was most recently consumed upstream.
Spring Integration 7.1.0
Spring Integration 7.0.0 - 7.0.5
Spring Integration 6.5.0 - 6.5.10
Spring Integration 6.4.0 - 6.4.12
Spring Integration 5.5.21 and earlier |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: ml-ioh: use raw_spinlock_t for the register lock
ioh_irq_type() is registered as the irq_chip .irq_set_type callback and
takes chip->spinlock with spin_lock_irqsave(). This callback is reached
from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while
the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled.
That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is
an rtmutex-backed sleeping lock, so acquiring it there is invalid.
ioh_irq_enable() and ioh_irq_disable() take the same lock from the
.irq_enable/.irq_disable callbacks, which are likewise invoked with
desc->lock held.
Convert the register lock to raw_spinlock_t. The same lock also
serializes the GPIO direction/value callbacks and the suspend/resume
register save/restore, and those critical sections only perform short
sequences of MMIO register accesses (ioread32()/iowrite32()); the
.irq_set_type callback additionally emits a dev_warn() on an unsupported
type. None of these are sleepable operations, so keeping this register
lock non-sleeping is appropriate for the irqchip callbacks and does not
change the GPIO-side locking contract.
This is the same fix as commit a02b8950d619 ("gpio: pch: use
raw_spinlock_t for the register lock"); this driver shares the same
structure as gpio-pch. |
| Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the same circuit, attaching an exit stream that would later end up orphan leaving a dangling circuit back-pointer and a use-after-free (UAF) when the circuit is freed. This is TROVE-2026-025. |
| In the Linux kernel, the following vulnerability has been resolved:
rqspinlock: Reset tail when preserving queue on deadlock
Currently, the destruction of the waiter queue is suppressed for
rqspinlock in cases where a deadlock is detected. Deadlock checks happen
relatively frequently (on entry for AA, within 1ms for ABBA), and waiter
threads may not be involved in locking scenarios involving deadlocks.
Thus, it is useful to not flush the queue and let other waiters take a
stab at acquiring the lock after we detect a deadlock and exit.
However, we need to follow the same logic as what we did previously for
the waitq_timeout label: reset the tail, and if we cannot, signal the
next waiter appropriately. In case of deadlocks, this signal would just
mark the MCS node as unlocked, and in case of timeouts, it would signal
RES_TIMEOUT_VAL. The difference thus is in the value propagated, which
decides whether the queue remains active or gets flushed.
Not doing the tail reset, and waiting for the next waiter can lead to
cases where we are the final waiter, and thus no next waiter arrives,
leading to intermittent stalls in this path. Once the next waiter does
join, we will be unblocked. In the theoretical case when the next waiter
never joins, we risk stalling indefinitely.
This can only happen for ABBA deadlocks, since entry into the wait queue
is guarded with AA checks. A precise sequence of executions leading up
to this scenario can be:
CPU 0 holds lock A.
CPU 1 holds lock B.
CPU 2 attempts lock B, becomes the pending waiter for B.
CPU 0 attempts lock B. B has locked+pending bits set, thus CPU 0 queues.
CPU 1 attempts lock A.
CPU 0 detects an ABBA deadlock.
Once deadlock detection happens for CPU 0, it will sit waiting for the
next waiter in the queue to populate node->next, which will experience
delays until such a waiter arrives.
Fix this by adjusting the logic for the check for deadlocks preceding
the waitq_timeout label. It would make sense to consolidate code for
both cases and use 'ret' to distinguish the value being propagated, but
that is left as an exercise for a future refactoring task to avoid diff
noise in this patch. |
| In the Linux kernel, the following vulnerability has been resolved:
tpm: tpm_tis_spi: Use wait_woken() in wait_for_tmp_stat()
wait_event_interruptible_timeout() evaluates its condition after setting
the current task state to TASK_INTERRUPTIBLE.
With CONFIG_DEBUG_ATOMIC_SLEEP this triggers a warning when the IRQ wait
path is used:
tpm_tis_status()
tpm_tis_spi_read_bytes()
tpm_tis_spi_transfer_full()
spi_bus_lock()
mutex_lock()
Address this with the following measures:
1. Call wait_tpm_stat_cond() only while tasking is running.
2. Use wait_woken() to wait for changes. |
| In the Linux kernel, the following vulnerability has been resolved:
openrisc: Fix jump_label smp syncing
The original commit 8c30b0018f9d ("openrisc: Add jump label support")
copies from arm64 and does not properly consider how icache invalidation
on remote cores works in OpenRISC. On OpenRISC remote icaches need to
be invalidated otherwise static key's may remain state after updating.
Fix SMP cache syncing by:
1. Properly invalidate remote core icaches on SMP systems by using
icache_all_inv. The old code uses kick_all_cpus_sync() which runs a
no-op IPI function call on remote CPU's which does execute a lot of
code and flushes many cache lines in the process, but does not flush
all and it's not correct on OpenRISC.
2. For architectures that do not have WRITETHROUGH caches be sure
to flush the dcache after patching.
To test this I first reproduced the issue using a custom test module
[0]. The test confirmed that some icache lines maintained stale
static_key code sequences after calling static_branch_enable(). After
this patch there are no longer jump_label coherency issues.
[0] https://github.com/stffrdhrn/or1k-utils/tree/master/tests/smp_static_key_test |
| In the Linux kernel, the following vulnerability has been resolved:
net: microchip: vcap: fix races on the shared Super VCAP block
The VCAP instances on a chip are not independent, yet they are locked
independently. On sparx5 and lan969x the IS0 and IS2 instances are
backed by the same Super VCAP hardware block and share its cache and
command registers: every access drives the shared VCAP_SUPER_CTRL
register and moves data through the shared cache registers.
Accessing one instance therefore races with accessing another. The
per-instance admin->lock cannot prevent this, as each instance takes a
different lock.
The locking issue is mostly disguised by the fact that the core usage of
the vcap api runs under rtnl. However, the full rule dump in debugfs
decodes rules straight from hardware (a READ command followed by a cache
read) and runs outside rtnl, so it races a concurrent tc-flower rule
write to another Super VCAP instance.
Besides corrupting the dump, the read repopulates the shared cache
between the writers cache fill and its write command, so the writer
commits the wrong data and corrupts the hardware entry.
Introduce vcap_lock() and vcap_unlock() helpers and route every rule
lock site in the VCAP API and its debugfs code through them. Replace the
per-instance admin->lock with a single mutex in struct vcap_control that
serializes access to all instances. The helpers reach it through a new
admin->vctrl back-pointer, and the clients initialise and destroy the
control lock instead of a per-instance one.
No path holds more than one instance lock, so collapsing them onto a
single mutex cannot self-deadlock. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them
Update nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.
This patch also disables BH when transmitting the skb to address a
possible migration to different CPU leading to imbalanced decrementation
of the recursion counters.
This is modeled after Florian Westphal's dev_xmit_recursion*() API
available since commit 97cdcf37b57e ("net: place xmit recursion in
softnet data") according to its current state in the tree. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_hfsc: Don't make class passive twice
update_vf() is called from two places for the same class during a single
dequeue when the class's child qdisc (e.g. codel/fq_codel) drops its last
packets while dequeuing:
1. The child calls qdisc_tree_reduce_backlog(), which, now that the child
is empty, invokes hfsc_qlen_notify() -> update_vf(cl, 0, 0) and turns
the class passive (cl_nactive is decremented up the hierarchy).
2. hfsc_dequeue() then calls update_vf(cl, qdisc_pkt_len(skb), cur_time)
to charge the dequeued bytes.
On the second call the class is already passive, but its child qdisc is
still empty, so update_vf() arms go_passive again:
if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
go_passive = 1;
The leaf is then skipped by the cl_nactive == 0 check inside the loop,
which does not clear go_passive, so the stale go_passive propagates to the
parent and decrements its cl_nactive a second time. A parent that still
has other active children is driven to cl_nactive == 0 and removed from
the vttree, even though those siblings are still backlogged. They are
never dequeued again and the qdisc stalls.
Fix this by only arming go_passive when the class is actually active, so an
already-passive class no longer triggers a second passive transition. The
byte accounting (cl->cl_total += len) still runs for every ancestor, so
dequeued bytes continue to be counted exactly once. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: fix UAF by restoring RCU-delayed inode freeing in bpffs
commit 4f375ade6aa9 ("bpf: Avoid RCU context warning when unpinning
htab with internal structs") moved inode cleanup from ->free_inode()
into ->destroy_inode() to avoid sleeping in RCU context when calling
bpf_any_put(). However this removed the RCU delay on freeing the
inode itself and the cached symlink body (i_link), both of which
can be accessed by RCU pathwalk (pick_link, may_lookup etc.).
This causes a use-after-free when a concurrent unlinkat() drops the
last inode reference and destroy_inode() frees the inode immediately,
while another task is still walking the path in RCU mode and reads
inode->i_opflags (offset +2) inside current_time() -> is_mgtime().
KASAN reports:
BUG: KASAN: slab-use-after-free in is_mgtime include/linux/fs.h:2313
Read of size 2 at addr ffff8880407e4282 (offset +2 = i_opflags)
The rules (per Al Viro):
->destroy_inode() called immediately, can sleep, use for blocking
cleanup e.g. bpf_any_put()
->free_inode() called after RCU grace period, use for freeing
inode and anything RCU-accessible e.g. i_link
Fix: split the two concerns properly:
- keep bpf_any_put() in bpf_destroy_inode() since it is blocking
and needs to run promptly
- introduce bpf_free_inode() to handle kfree(i_link) and
free_inode_nonrcu() with proper RCU delay, preventing the UAF |
