| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs3: cap RESTART_TABLE free-chain walker at rt->used
A crafted NTFS3 disk image triggers an in-kernel infinite loop at
mount time, hanging the mounting thread and firing the soft-lockup
watchdog within ~22s on multi-CPU hosts (panic with
kernel.softlockup_panic=1). The bug is reachable from desktop USB
auto-mount on distributions where udisks2 routes the NTFS signature
to the in-tree ntfs3 driver (Arch family and an increasing fraction
of Fedora / openSUSE / RHEL deployments); CAP_SYS_ADMIN-class manual
mount elsewhere.
check_rstbl()'s second walker iterates the free-entry singly-linked
list headed by rt->first_free with no upper bound on iteration count:
for (off = ff; off;) {
if (off == RESTART_ENTRY_ALLOCATED)
return false;
off = le32_to_cpu(*(__le32 *)Add2Ptr(rt, off));
if (off > ts - sizeof(__le32))
return false;
}
The existing guards cover three exits: end-of-list (off == 0), the
in-use marker (off == RESTART_ENTRY_ALLOCATED), and out-of-bounds
(off > ts - sizeof(__le32)). None of the three prevents an
in-bounds cycle.
A crafted on-disk RESTART_TABLE whose free chain contains a
self-loop or A->B->A cycle whose offsets satisfy:
- in range [sizeof(struct RESTART_TABLE), ts - sizeof(__le32)]
- (off - sizeof(struct RESTART_TABLE)) % rsize == 0
passes all existing guards and spins the mount-time thread forever.
Reproduced in UML by hand-forging a 2 MB NTFS3 image whose journal
RESTART_TABLE first_free = 0x18 and whose entry at offset 0x18
stores 0x18 as its next pointer; mount of the forged image with
the in-tree ntfs3 driver never returns.
Bound the walker by rt->used. Each entry on a legitimate free
chain is unique, and the total slot count is ne = le16_to_cpu
(rt->used). A traversal that visits more than ne slots is by
construction malformed; reject it as a corrupt RESTART_TABLE.
After this patch, mount of the forged image returns with -EINVAL
and a log_replay failure message, and mkntfs-produced legitimate
images mount cleanly (verified in the same UML harness). |
| In the Linux kernel, the following vulnerability has been resolved:
net/9p: fix infinite loop in p9_client_rpc on fatal signal
When p9_client_rpc() is called with type P9_TFLUSH and the transport
has no peer (e.g. fd transport backed by pipes with no 9p server),
a fatal signal causes an infinite loop:
again:
err = io_wait_event_killable(req->wq, ...)
/* SIGKILL wakes the task, returns -ERESTARTSYS */
if (err == -ERESTARTSYS && c->status == Connected &&
type == P9_TFLUSH) {
sigpending = 1;
clear_thread_flag(TIF_SIGPENDING);
goto again;
}
clear_thread_flag() clears TIF_SIGPENDING before jumping back to
io_wait_event_killable(). signal_pending_state() checks TIF_SIGPENDING,
finds it zero, and the task goes to sleep again. The task can only wake
on the next signal delivery that calls signal_wake_up() and sets
TIF_SIGPENDING again. When that happens the loop repeats, clears
TIF_SIGPENDING, and sleeps again indefinitely.
This is triggered in practice by coredump_wait(): when a thread in a
multi-threaded process causes a coredump (e.g. via SIGSYS from Syscall
User Dispatch), coredump_wait() sends SIGKILL to all other threads and
waits for them to call mm_release(). If one of those threads is blocked
in p9_client_rpc() over an fd transport with no peer, it enters the
P9_TFLUSH loop and never calls mm_release(), so coredump_wait() stalls
forever:
INFO: task syz.0.18:676 blocked for more than 143 seconds.
Not tainted 6.12.77+ #1
task:syz.0.18 state:D stack:27600 pid:676 tgid:673 ppid:630 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5344 [inline]
__schedule+0xcb4/0x5d50 kernel/sched/core.c:6724
__schedule_loop kernel/sched/core.c:6801 [inline]
schedule+0xe5/0x350 kernel/sched/core.c:6816
schedule_timeout+0x253/0x290 kernel/time/timer.c:2593
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common+0x409/0x600 kernel/sched/completion.c:116
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion_state+0x1d/0x40 kernel/sched/completion.c:264
coredump_wait fs/coredump.c:448 [inline]
do_coredump+0x854/0x4350 fs/coredump.c:629
get_signal+0x1425/0x2730 kernel/signal.c:2903
arch_do_signal_or_restart+0x81/0x880 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xf9/0x160 kernel/entry/common.c:218
do_syscall_64+0x102/0x220 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Fix: check fatal_signal_pending() before clearing TIF_SIGPENDING in the
P9_TFLUSH retry loop. At that point TIF_SIGPENDING is still set, so
fatal_signal_pending() works correctly. If a fatal signal is pending,
jump to recalc_sigpending to restore TIF_SIGPENDING and return
-ERESTARTSYS to the caller.
The same defect is present in stable kernels back to 5.4. On those
kernels the infinite loop is broken earlier by a second SIGKILL from
the parent process (e.g. kill_and_wait() retrying after a timeout),
resulting in a zombie process and a shutdown delay rather than a
permanent D-state hang, but the underlying flaw is the same.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: fix infinite loop in __tipc_nl_compat_dumpit
cmd->dumpit callback can return a negative errno, causing an infinite
loop due to the while(len) condition. As the loop never terminates,
genl_mutex is never released, and other tasks waiting on it starve in D
state.
Check dumpit's return value, propagate it and jump to err_out on error. |
| In the Linux kernel, the following vulnerability has been resolved:
s390: Revert support for DCACHE_WORD_ACCESS
load_unaligned_zeropad() reads eight bytes from unaligned addresses and may
cross page boundaries. It handles exceptions which may happen if reading
from the second page results in an exception.
For pages which are donated to the Ultravisor for secure execution purposes
the do_secure_storage_access() exception handler however does not handle
such exceptions correctly. Such an exception may result in an endless
exception loop which will never be resolved.
An attempt to fix this [1] turned out to be not sufficient. For now revert
load_unaligned_zeropad() until this problem has been resolved in a proper
way.
Note that the implementation of load_unaligned_zeropad() itself is
correct. The revert is just a temporary workaround until there is complete
fix for secure storage access exceptions.
[1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory") |
| In the Linux kernel, the following vulnerability has been resolved:
USB: serial: digi_acceleport: fix hard lockup on disconnect
If submitting the OOB write urb fails persistently (e.g if the device is
being disconnected) the driver would loop indefinitely with interrupts
disabled.
Check for urb submission errors when sending OOB commands to avoid
hanging if, for example, open(), set_termios() or close() races with a
physical disconnect.
This is issue was flagged by Sashiko when reviewing an unrelated change
to the driver. |
| In the Linux kernel, the following vulnerability has been resolved:
iommufd: Break the loop on failure in iommufd_fault_fops_read()
On a copy_to_user() failure inside the inner list_for_each_entry, only the
inner loop breaks; the outer while re-fetches the just-restored fault group
and retries the failing copy_to_user() forever, spinning the reader at 100%
CPU with fault->mutex held.
Check rc after the inner loop and break the outer while as well. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: advance loop vars in cfg80211_merge_profile()
cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS
profile that has been split across multiple consecutive MBSSID elements.
Its while-loop calls
cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem)
but never advances mbssid_elem or sub_elem inside the body. Each
iteration therefore searches for a continuation that follows the same
fixed pair; the helper returns the same next_mbssid; and the same
next_sub bytes are memcpy()'d into merged_ie at a growing offset until
the buffer fills.
Advance both mbssid_elem and sub_elem to the just-consumed continuation
so the next call to cfg80211_get_profile_continuation() searches for a
further continuation beyond it (or returns NULL when none exists).
A specially-crafted malicious beacon can take advantage of this bug
to cause the kernel to spend an excessive amount of time in
cfg80211_merge_profile (up to as much as 2ms per beacon received),
which could theoretically be abused in some way. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/napi: cap busy_poll_to 10 msec
Currently there's no cap on the maximum amount of time that napi is
allowed to poll if no events are found, which can lead to kernel
complaints on a task being stuck as there's no conditional rescheduling
done within that loop.
Just cap it to 10 msec in total, that's already way above any kind of
sane value that will reap any benefits, yet low enough that it's
nowhere near being able to trigger preemption complaints. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/ttm: Fix ttm_bo_swapout() infinite LRU walk on swapout failure
When ttm_tt_swapout() fails, the current code calls
ttm_resource_add_bulk_move() followed by ttm_resource_move_to_lru_tail()
to restore the resource's bulk_move membership.
However, ttm_resource_move_to_lru_tail() places the resource at the tail
of the LRU list which, relative to the walk cursor's hitch node (placed
immediately after the resource when it was yielded), puts the resource
*in front of the* the hitch. The next list_for_each_entry_continue() from
the hitch finds the same resource again, causing an infinite loop.
Fix by deferring del_bulk_move to the success path only.
On the success path, TTM_TT_FLAG_SWAPPED has just been set by
ttm_tt_swapout() but the resource is still tracked in the bulk_move range,
so ttm_resource_del_bulk_move()'s !ttm_resource_unevictable() guard would
incorrectly skip the removal. Introduce
ttm_resource_del_bulk_move_unevictable() which bypasses that guard. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup failure
Apply the same fix as b2ed01e7ad ("drm/ttm: Fix ttm_bo_swapout()
infinite LRU walk on swapout failure") to the ttm_bo_shrink() path.
Move del_bulk_move from before the backup to after success only,
using ttm_resource_del_bulk_move_unevictable() since the resource
is now unevictable once fully backed up. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: stop hash:* range iteration at end
The following hash set variants:
hash:ip,mark
hash:ip,port
hash:ip,port,ip
hash:ip,port,net
iterate IPv4 ranges with a 32-bit iterator.
The iterator must stop once the last address in the requested range has
been processed. Advancing it once more can move the traversal state past
the end of the request, so a later retry may continue from an unintended
position.
Handle the iterator increment explicitly at the end of the loop and stop
once the upper bound has been processed. This keeps the existing retry
behaviour intact for valid ranges while preventing traversal from
continuing past the original boundary. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Avoid potential endless loop in convert_chmap_v3()
The convert_chmap_v3() has a loop with its increment size of
cs_desc->wLength, but we forgot to validate cs_desc->wLength itself,
which may lead to potential endless loop by a malformed descriptor.
Add a proper size check to abort the loop for plugging the hole. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid5: fix soft lockup in retry_aligned_read()
When retry_aligned_read() encounters an overlapped stripe, it releases
the stripe via raid5_release_stripe() which puts it on the lockless
released_stripes llist. In the next raid5d loop iteration,
release_stripe_list() drains the stripe onto handle_list (since
STRIPE_HANDLE is set by the original IO), but retry_aligned_read()
runs before handle_active_stripes() and removes the stripe from
handle_list via find_get_stripe() -> list_del_init(). This prevents
handle_stripe() from ever processing the stripe to resolve the
overlap, causing an infinite loop and soft lockup.
Fix this by using __release_stripe() with temp_inactive_list instead
of raid5_release_stripe() in the failure path, so the stripe does not
go through the released_stripes llist. This allows raid5d to break out
of its loop, and the overlap will be resolved when the stripe is
eventually processed by handle_stripe(). |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring: don't flood a cancelling task with task_work
io_ring_exit_work() asks each task which has used the ring to remove its
tctx node, by task_work, and repeats that until the list is empty.
io_tctx_exit_cb() doesn't touch the node while the task is in
io_uring_cancel_generic(), which removes all the nodes at its end. So the
work item queues the callback again as soon as it has completed, for
nothing.
That is more than a waste of time. task_work_run() only returns when it
finds the list empty. If the rings are released from inside the
cancellation, because requests of other rings held the last references to
their files, up to 64 work items keep sending callbacks to the one task
which is running them. It never finds the list empty, never gets back to
the cancellation, the nodes stay, and so it goes on: a task with 60 pairs
of rings which poll each other ran 280000 callbacks in 5 seconds, 20
seconds after exit_group(). It ends when all the senders happen to be late
at the same time. Until then the task keeps a CPU and the work items busy.
An exiting task can't be killed meanwhile. execve() cancels the requests in
the same way, so a live task can get stuck there as well, for minutes. If
it takes more than five, the work items run into the
WARN_ON_ONCE(time_after(jiffies, timeout)) of io_ring_exit_work(). No
privilege is needed for any of this.
If the callback has met a task in cancellation, wait a little before it is
sent again. Nobody has to wake the work item up for that: either the node
is gone by then, or it is the turn of the next round. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/wait: don't spin on a stuck overflow list
As long as IO_CHECK_CQ_OVERFLOW_BIT is set, io_cqring_wait_schedule()
returns right away, before it gets to look at signals or arms the timeout,
for io_cqring_wait() to flush the overflow list. If that doesn't empty the
list, and the CQ ring doesn't hold the number of events the caller wants,
the loop starts over, with the same result. The task spins in the kernel,
and can't be killed.
The assumption is that this can't happen: if CQEs can't be flushed, the
ring is full, and min_events is capped to the size of the ring. But:
- With IORING_SETUP_CQE_MIXED a 32b CQE needs two contiguous entries. It
is stuck on the list if a single one is free, and then the ring holds
less than cq_entries events. A single threaded application that asks
for as many events as the ring has entries never gets out of
io_uring_enter().
- Whether the ring is full is up to the CQ head, which the application
can write to. While one thread waits for events on an empty ring,
another one can move the head back so that the ring looks full and
have a CQE overflow. The waiter can't be stopped any more, not even by
SIGKILL.
Only the application can make room in the CQ ring. Return to it if the
list could not be flushed. |
| A flaw was found in the SAML 1.1 XML parsing logic of Keycloak, an open-source identity and access management solution. The issue occurs when the parser encounters unexpected elements within a security token's key information section, causing the processing thread to enter an infinite loop. An unauthenticated remote attacker could exploit this by sending specially crafted requests, leading to 100% CPU usage and a total denial of service that requires a server restart to resolve. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid5: fix IO hang with degraded array with llbitmap
When llbitmap bit state is still unwritten, any new write should force
rcw, as bitmap_ops->blocks_synced() is checked in handle_stripe_dirtying().
However, later the same check is missing in need_this_block(), causing
stripe to deadloop during handling because handle_stripe() will decide
to go to handle_stripe_fill(), meanwhile need_this_block() always return
0 and nothing is handled. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/rt: Skip currently executing CPU in rto_next_cpu()
CPU0 becomes overloaded when hosting a CPU-bound RT task, a non-CPU-bound
RT task, and a CFS task stuck in kernel space. When other CPUs switch from
RT to non-RT tasks, RT load balancing (LB) is triggered; with
HAVE_RT_PUSH_IPI enabled, they send IPIs to CPU0 to drive the execution
of rto_push_irq_work_func. During push_rt_task on CPU0,
if next_task->prio < rq->donor->prio, resched_curr() sets NEED_RESCHED
and after the push operation completes, CPU0 calls rto_next_cpu().
Since only CPU0 is overloaded in this scenario, rto_next_cpu() should
ideally return -1 (no further IPI needed).
However, multiple CPUs invoking tell_cpu_to_push() during LB increments
rd->rto_loop_next. Even when rd->rto_cpu is set to -1, the mismatch between
rd->rto_loop and rd->rto_loop_next forces rto_next_cpu() to restart its
search from -1. With CPU0 remaining overloaded (satisfying rt_nr_migratory
&& rt_nr_total > 1), it gets reselected, causing CPU0 to queue irq_work to
itself and send self-IPIs repeatedly. As long as CPU0 stays overloaded and
other CPUs run pull_rt_tasks(), it falls into an infinite self-IPI loop,
which triggers a CPU hardlockup due to continuous self-interrupts.
The trigging scenario is as follows:
cpu0 cpu1 cpu2
pull_rt_task
tell_cpu_to_push
<------------irq_work_queue_on
rto_push_irq_work_func
push_rt_task
resched_curr(rq) pull_rt_task
rto_next_cpu tell_cpu_to_push
<-------------------------- atomic_inc(rto_loop_next)
rd->rto_loop != next
rto_next_cpu
irq_work_queue_on
rto_push_irq_work_func
Fix redundant self-IPI by filtering the initiating CPU in rto_next_cpu().
This solution has been verified to effectively eliminate spurious self-IPIs
and prevent CPU hardlockup scenarios. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode
PCIe endpoints with ATS enabled and passed through to userspace
(e.g., QEMU, DPDK) can hard-lock the host when their link drops,
either by surprise removal or by a link fault.
Commit 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation
request when device is disconnected") adds pci_dev_is_disconnected()
to devtlb_invalidation_with_pasid() so ATS invalidation is skipped
only when the device is being safely removed, but it applies only
when Intel IOMMU scalable mode is enabled.
With scalable mode disabled or unsupported, a system hard-lock
occurs when a PCIe endpoint's link drops because the Intel IOMMU
waits indefinitely for an ATS invalidation that cannot complete.
Call Trace:
qi_submit_sync
qi_flush_dev_iotlb
__context_flush_dev_iotlb.part.0
domain_context_clear_one_cb
pci_for_each_dma_alias
device_block_translation
blocking_domain_attach_dev
iommu_deinit_device
__iommu_group_remove_device
iommu_release_device
iommu_bus_notifier
blocking_notifier_call_chain
bus_notify
device_del
pci_remove_bus_device
pci_stop_and_remove_bus_device
pciehp_unconfigure_device
pciehp_disable_slot
pciehp_handle_presence_or_link_change
pciehp_ist
Commit 81e921fd3216 ("iommu/vt-d: Fix NULL domain on device release")
adds intel_pasid_teardown_sm_context() to intel_iommu_release_device(),
which calls qi_flush_dev_iotlb() and can also hard-lock the system
when a PCIe endpoint's link drops.
Call Trace:
qi_submit_sync
qi_flush_dev_iotlb
__context_flush_dev_iotlb.part.0
intel_context_flush_no_pasid
device_pasid_table_teardown
pci_pasid_table_teardown
pci_for_each_dma_alias
intel_pasid_teardown_sm_context
intel_iommu_release_device
iommu_deinit_device
__iommu_group_remove_device
iommu_release_device
iommu_bus_notifier
blocking_notifier_call_chain
bus_notify
device_del
pci_remove_bus_device
pci_stop_and_remove_bus_device
pciehp_unconfigure_device
pciehp_disable_slot
pciehp_handle_presence_or_link_change
pciehp_ist
Sometimes the endpoint loses connection without a link-down event
(e.g., due to a link fault); killing the process (virsh destroy)
then hard-locks the host.
Call Trace:
qi_submit_sync
qi_flush_dev_iotlb
__context_flush_dev_iotlb.part.0
domain_context_clear_one_cb
pci_for_each_dma_alias
device_block_translation
blocking_domain_attach_dev
__iommu_attach_device
__iommu_device_set_domain
__iommu_group_set_domain_internal
iommu_detach_group
vfio_iommu_type1_detach_group
vfio_group_detach_container
vfio_group_fops_release
__fput
pci_dev_is_disconnected() only covers safe-removal paths;
pci_device_is_present() tests accessibility by reading
vendor/device IDs and internally calls pci_dev_is_disconnected().
On a ConnectX-5 (8 GT/s, x2) this costs ~70 µs.
Since __context_flush_dev_iotlb() is only called on
{attach,release}_dev paths (not hot), add pci_device_is_present()
there to skip inaccessible devices and avoid the hard-lock. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/pxp: Clear restart flag in pxp_start after jumping back
If we don't clear the flag we'll keep jumping back at the beginning of
the function once we reach the end.
(cherry picked from commit 0850ec7bb2459602351639dccf7a68a03c9d1ee0) |
