KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Fix length check __import_wp_info()
struct kvm_hw_breakpoint::len is a __u64 that is fully controlled by user
space. This is then assigned to wp_info->len, which is an int. The bounds
check is done on the truncated value while the allocation uses the
untruncated one:
wp_info->len = bp_data->len;
[...]
if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE)
return -EINVAL;
wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL_ACCOUNT);
Use the validated value for the allocation as intended. Without this
fix userspace can trigger >4GB allocations which will fai
KVM: s390: Fix memory leak in guest debug handling
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Fix memory leak in guest debug handling
bp_data is freed only for the error case by kfree(bp_data).
Every successful KVM_SET_GUEST_DEBUG will leak bp_data.
KVM: s390: Fix old_data leak in guest debug error path
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Fix old_data leak in guest debug error path
__import_wp_info() allocates a per-watchpoint old_data buffer to back up
the original guest memory contents. If a later watchpoint of the same
KVM_SET_GUEST_DEBUG request fails to import, kvm_s390_import_bp_data()
jumps to the error label, which frees the wp_info array but not the
old_data buffers of the entries that were imported successfully. Up to
MAX_BP_COUNT - 1 buffers of up to MAX_WP_SIZE bytes are leaked per failed
request, and the request can be repeated.
Create error handling for cleaning up all created old_d
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Free guest debug data on vcpu destroy
kvm_s390_clear_bp_data() is only called from
kvm_arch_vcpu_ioctl_set_guest_debug(), i.e. when user space changes or
disables debugging. A vCPU that is destroyed while hardware breakpoints
are still armed - the normal case when the VMM just exits or crashes -
leaks hw_bp_info, hw_wp_info and all old_data buffers, since generic KVM
frees the vCPU right after kvm_arch_vcpu_destroy().
That is bounded by MAX_BP_COUNT entries, so roughly 8 KiB per vCPU, but
it is unbounded over VM lifetimes. The allocations are
GFP_KERNEL_ACCOUNT,
KVM: s390: Take srcu when importing watchpoint data
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Take srcu when importing watchpoint data
__import_wp_info() backs up the original guest memory contents of a
watchpoint with read_guest_abs(), which is kvm_read_guest() and therefore
resolves the memslot via __kvm_memslots(). That requires kvm->srcu (or
kvm->slots_lock) to be held, otherwise a concurrent memslot update can
free the memslots array under us once its SRCU grace period has elapsed.
As this is not fast path, following lock ordering (mutex first, then
srcu) take the big hammer and hold the srcu for the full import.
KVM: s390: Zero initialize data structures for inject_pfault_token
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Zero initialize data structures for inject_pfault_token
__kvm_inject_pfault_token() only sets .type and .u.ext.ext_params2 of
the on-stack struct kvm_s390_irq but the full ext substructure is copied
into the cpu local variable on inject. ext_params and pad contain stale
stack values.
Interrupt delivery only uses ext_params2, so nothing leaks to the guest,
but a host user can use the migration ioctls to get to the data.
Fix by zero-initializing the irq struct.
Do the same for the inti data structure.
KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save
MAPC with V=0 drops ite->collection but leaves the ITE on the device's
ITT list, and vgic_its_save_ite() dereferences it unconditionally. A
guest that issues MAPD, MAPTI and then MAPC(V=0) therefore oopses the
host when the VMM issues KVM_DEV_ARM_ITS_SAVE_TABLES to migrate it.
That sequence is UNPREDICTABLE per the architecture, but KVM already
handles the resulting state in the translate, MOVI and DISCARD paths.
Save a zeroed entry, which vgic_its_restore_ite() reads back as
invalid. Skipping the ITE in
LoongArch: KVM: Free init resources if kvm_init() fails
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Free init resources if kvm_init() fails
kvm_loongarch_init() calls kvm_loongarch_env_init() to allocate the
per-CPU kvm_context (vmcs) and kvm_loongarch_ops and to register the
perf callbacks, and then calls kvm_init(). If kvm_init() fails its
result is returned directly, but since module_init() does not run the
module_exit() stuff on failure, so kvm_loongarch_env_exit() is never
called and those resources are leaked.
So call kvm_loongarch_env_exit() when kvm_init() fails, matching the
teardown-on-failure pattern used by riscv_kvm_init().
LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY
kvm_arch_prepare_memory_region() computes new->arch.flags, i.e. whether
a memslot is KVM_MEM_HUGEPAGE_CAPABLE or KVM_MEM_HUGEPAGE_INCAPABLE,
only for KVM_MR_CREATE and KVM_MR_MOVE, and returns early for every
other change. But the generic code allocates a zeroed memslot for every
change and never copies old->arch, so after a KVM_MR_FLAGS_ONLY update,
e.g. toggling KVM_MEM_LOG_DIRTY_PAGES for live migration, the active
memslot has arch.flags == 0.
With both flags clear, fault_supports_huge_mapping() falls thro
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Fix acpi_package_ids[] array overflow
With LoongArch virt machine, a typical setting is one core per socket,
there will max 256 sockets (packages) on one VM. With PPTT acpi table,
array acpi_package_ids[] will be overflowed.
Here change the array size of acpi_package_ids[] with the max value of
MAX_PACKAGES and KVM_MAX_VCPUS.
LoongArch: Do not save/restore percpu base register in rethook trampoline
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Do not save/restore percpu base register in rethook trampoline
The rethook trampoline saves $r21 ($u0), the percpu base, into its frame
at entry and restores it at exit. Inbetween rethook_trampoline_handler()
may schedule via preempt_enable_notrace().
If the task migrates to another CPU, the frame's $r21 holds the old
CPU's percpu base, and restoring it poisons $r21 on the new CPU. Until
the next user->kernel transition heals $r21, all this_cpu_*() accesses
(runqueues, RCU per-CPU data, timer tick programming, FPU ownership)
hit the wrong CPU's percpu area.
Und
LoongArch: Avoid preempt count underflow without probe
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Avoid preempt count underflow without probe
LoongArch uses break 11 for the breakpoint placed after an instruction
that Kprobes executes out of line. Since userspace can issue the same
break instruction, do_bp() can reach kprobe_singlestep_handler() when
there is no current probe.
The handler actually returns false in this case, but it first calls
preempt_enable_no_resched(). The corresponding preempt_disable() is done
by kprobe_breakpoint_handler() on a real Kprobe hit, so it has not run
here. As a result, an ordinary userspace breakpoint (code 11) underflows
t
media: airspy: use vb2_video_unregister_device() on disconnect to fix NULL deref
In the Linux kernel, the following vulnerability has been resolved:
media: airspy: use vb2_video_unregister_device() on disconnect to fix NULL deref
airspy_disconnect() clears s->udev under v4l2_lock, but
airspy_stop_streaming() unconditionally calls airspy_ctrl_msg() and
airspy_free_stream_bufs() afterwards. If a streaming user closes the
device after disconnect, stop_streaming() runs and dereferences the
NULL s->udev:
airspy_stop_streaming()
airspy_ctrl_msg(s, CMD_RECEIVER_MODE, 0, 0, NULL, 0)
usb_sndctrlpipe(s->udev, 0) /* NULL deref */
airspy_free_stream_bufs(s)
usb_free_coherent(s->udev, ...) /* NULL
media: cec: core: Fix kmemleak due to missed rc_free_device() call
In the Linux kernel, the following vulnerability has been resolved:
media: cec: core: Fix kmemleak due to missed rc_free_device() call
The commit dccc0c3ddf8f ("media: rc: fix race between unregister and
urb/irq callbacks") removed the implicit call to rc_free_device() from
rc_unregister_device(). However, the commit missed to remove the NULL
assignment of adap->rc that is now causing rc_free_device() to never be
called on an allocated rc device.
kmemleak reports following after e.g. dw-hdmi unbind:
unreferenced object 0xffff00010ac10000 (size 4096):
comm "kworker/u16:1", pid 39, jiffies 4294897739
hex dump (first 32 bytes):
20 23
media: cec: disable delayed work before freeing an interrupted transmit
In the Linux kernel, the following vulnerability has been resolved:
media: cec: disable delayed work before freeing an interrupted transmit
cec_transmit_msg_fh() drops adap->lock to wait for a blocking transmit in
wait_for_completion_killable(). If that wait is interrupted by a signal,
cancel_delayed_work_sync() can run before the CEC kthread arms the reply
timeout via schedule_delayed_work(&data->work) in cec_transmit_done_ts().
The work is then armed after the cancel, and the data is freed with its
delayed_work still pending:
ODEBUG: free active (active state 0) object: ... hint: cec_wait_timeout
Use disable_delayed_work_sync(): it ca
In the Linux kernel, the following vulnerability has been resolved:
media: cec: extron-da-hd-4k-plus: add sanity check
Add check to prevent overflowing msg.msg[] in case the incoming data
is malformed.
In the Linux kernel, the following vulnerability has been resolved:
media: cec: Serialize exclusive follower delivery
cec_receive_notify() reads the exclusive follower pointer without the
adapter lock. Serialize the no-follower check and message delivery
against mode changes and release.
media: cedrus: fix memory leak in cedrus_init_ctrls()
In the Linux kernel, the following vulnerability has been resolved:
media: cedrus: fix memory leak in cedrus_init_ctrls()
In cedrus_init_ctrls(), the V4L2 control handler is initialized before
allocating memory for ctx->ctrls. If this allocation fails, the function
returns -ENOMEM without freeing the previously allocated handler
resources, leading to a memory leak.
Fix this by calling v4l2_ctrl_handler_free() on the ctx->ctrls allocation
failure path.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet p
media: cobalt: Avoid freeing ALSA private data twice
In the Linux kernel, the following vulnerability has been resolved:
media: cobalt: Avoid freeing ALSA private data twice
snd_cobalt_card_create() stores cobsc in sc->private_data and installs
snd_cobalt_card_private_free() as sc->private_free. From that point,
snd_card_free(sc) releases cobsc through the ALSA card cleanup path.
If cobalt_alsa_init() fails after snd_cobalt_card_create(), the
err_exit_free path calls snd_card_free(sc) and then kfree(cobsc). That
second free releases the same object again.
Remove the explicit kfree(cobsc) and leave ownership with the ALSA card.
This issue was found by a static analysis checker and confirmed