Security Vulnerabilities
- CVEs Published In 2024
In the Linux kernel, the following vulnerability has been resolved:
s390/iucv: MSG_PEEK causes memory leak in iucv_sock_destruct()
Passing MSG_PEEK flag to skb_recv_datagram() increments skb refcount
(skb->users) and iucv_sock_recvmsg() does not decrement skb refcount
at exit.
This results in skb memory leak in skb_queue_purge() and WARN_ON in
iucv_sock_destruct() during socket close. To fix this decrease
skb refcount by one if MSG_PEEK is set in order to prevent memory
leak and WARN_ON.
WARNING: CPU: 2 PID: 6292 at net/iucv/af_iucv.c:286 iucv_sock_destruct+0x144/0x1a0 [af_iucv]
CPU: 2 PID: 6292 Comm: afiucv_test_msg Kdump: loaded Tainted: G W 6.10.0-rc7 #1
Hardware name: IBM 3931 A01 704 (z/VM 7.3.0)
Call Trace:
[<001587c682c4aa98>] iucv_sock_destruct+0x148/0x1a0 [af_iucv]
[<001587c682c4a9d0>] iucv_sock_destruct+0x80/0x1a0 [af_iucv]
[<001587c704117a32>] __sk_destruct+0x52/0x550
[<001587c704104a54>] __sock_release+0xa4/0x230
[<001587c704104c0c>] sock_close+0x2c/0x40
[<001587c702c5f5a8>] __fput+0x2e8/0x970
[<001587c7024148c4>] task_work_run+0x1c4/0x2c0
[<001587c7023b0716>] do_exit+0x996/0x1050
[<001587c7023b13aa>] do_group_exit+0x13a/0x360
[<001587c7023b1626>] __s390x_sys_exit_group+0x56/0x60
[<001587c7022bccca>] do_syscall+0x27a/0x380
[<001587c7049a6a0c>] __do_syscall+0x9c/0x160
[<001587c7049ce8a8>] system_call+0x70/0x98
Last Breaking-Event-Address:
[<001587c682c4a9d4>] iucv_sock_destruct+0x84/0x1a0 [af_iucv]
In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix use-after-free of slot->bus on hot remove
Dennis reports a boot crash on recent Lenovo laptops with a USB4 dock.
Since commit 0fc70886569c ("thunderbolt: Reset USB4 v2 host router") and
commit 59a54c5f3dbd ("thunderbolt: Reset topology created by the boot
firmware"), USB4 v2 and v1 Host Routers are reset on probe of the
thunderbolt driver.
The reset clears the Presence Detect State and Data Link Layer Link Active
bits at the USB4 Host Router's Root Port and thus causes hot removal of the
dock.
The crash occurs when pciehp is unbound from one of the dock's Downstream
Ports: pciehp creates a pci_slot on bind and destroys it on unbind. The
pci_slot contains a pointer to the pci_bus below the Downstream Port, but
a reference on that pci_bus is never acquired. The pci_bus is destroyed
before the pci_slot, so a use-after-free ensues when pci_slot_release()
accesses slot->bus.
In principle this should not happen because pci_stop_bus_device() unbinds
pciehp (and therefore destroys the pci_slot) before the pci_bus is
destroyed by pci_remove_bus_device().
However the stacktrace provided by Dennis shows that pciehp is unbound from
pci_remove_bus_device() instead of pci_stop_bus_device(). To understand
the significance of this, one needs to know that the PCI core uses a two
step process to remove a portion of the hierarchy: It first unbinds all
drivers in the sub-hierarchy in pci_stop_bus_device() and then actually
removes the devices in pci_remove_bus_device(). There is no precaution to
prevent driver binding in-between pci_stop_bus_device() and
pci_remove_bus_device().
In Dennis' case, it seems removal of the hierarchy by pciehp races with
driver binding by pci_bus_add_devices(). pciehp is bound to the
Downstream Port after pci_stop_bus_device() has run, so it is unbound by
pci_remove_bus_device() instead of pci_stop_bus_device(). Because the
pci_bus has already been destroyed at that point, accesses to it result in
a use-after-free.
One might conclude that driver binding needs to be prevented after
pci_stop_bus_device() has run. However it seems risky that pci_slot points
to pci_bus without holding a reference. Solely relying on correct ordering
of driver unbind versus pci_bus destruction is certainly not defensive
programming.
If pci_slot has a need to access data in pci_bus, it ought to acquire a
reference. Amend pci_create_slot() accordingly. Dennis reports that the
crash is not reproducible with this change.
Abridged stacktrace:
pcieport 0000:00:07.0: PME: Signaling with IRQ 156
pcieport 0000:00:07.0: pciehp: Slot #12 AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
pci_bus 0000:20: dev 00, created physical slot 12
pcieport 0000:00:07.0: pciehp: Slot(12): Card not present
...
pcieport 0000:21:02.0: pciehp: pcie_disable_notification: SLOTCTRL d8 write cmd 0
Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI
CPU: 13 UID: 0 PID: 134 Comm: irq/156-pciehp Not tainted 6.11.0-devel+ #1
RIP: 0010:dev_driver_string+0x12/0x40
pci_destroy_slot
pciehp_remove
pcie_port_remove_service
device_release_driver_internal
bus_remove_device
device_del
device_unregister
remove_iter
device_for_each_child
pcie_portdrv_remove
pci_device_remove
device_release_driver_internal
bus_remove_device
device_del
pci_remove_bus_device (recursive invocation)
pci_remove_bus_device
pciehp_unconfigure_device
pciehp_disable_slot
pciehp_handle_presence_or_link_change
pciehp_ist
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Get rid of userspace_irqchip_in_use
Improper use of userspace_irqchip_in_use led to syzbot hitting the
following WARN_ON() in kvm_timer_update_irq():
WARNING: CPU: 0 PID: 3281 at arch/arm64/kvm/arch_timer.c:459
kvm_timer_update_irq+0x21c/0x394
Call trace:
kvm_timer_update_irq+0x21c/0x394 arch/arm64/kvm/arch_timer.c:459
kvm_timer_vcpu_reset+0x158/0x684 arch/arm64/kvm/arch_timer.c:968
kvm_reset_vcpu+0x3b4/0x560 arch/arm64/kvm/reset.c:264
kvm_vcpu_set_target arch/arm64/kvm/arm.c:1553 [inline]
kvm_arch_vcpu_ioctl_vcpu_init arch/arm64/kvm/arm.c:1573 [inline]
kvm_arch_vcpu_ioctl+0x112c/0x1b3c arch/arm64/kvm/arm.c:1695
kvm_vcpu_ioctl+0x4ec/0xf74 virt/kvm/kvm_main.c:4658
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__arm64_sys_ioctl+0x108/0x184 fs/ioctl.c:893
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x78/0x1b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xe8/0x1b0 arch/arm64/kernel/syscall.c:132
do_el0_svc+0x40/0x50 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x14c arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
The following sequence led to the scenario:
- Userspace creates a VM and a vCPU.
- The vCPU is initialized with KVM_ARM_VCPU_PMU_V3 during
KVM_ARM_VCPU_INIT.
- Without any other setup, such as vGIC or vPMU, userspace issues
KVM_RUN on the vCPU. Since the vPMU is requested, but not setup,
kvm_arm_pmu_v3_enable() fails in kvm_arch_vcpu_run_pid_change().
As a result, KVM_RUN returns after enabling the timer, but before
incrementing 'userspace_irqchip_in_use':
kvm_arch_vcpu_run_pid_change()
ret = kvm_arm_pmu_v3_enable()
if (!vcpu->arch.pmu.created)
return -EINVAL;
if (ret)
return ret;
[...]
if (!irqchip_in_kernel(kvm))
static_branch_inc(&userspace_irqchip_in_use);
- Userspace ignores the error and issues KVM_ARM_VCPU_INIT again.
Since the timer is already enabled, control moves through the
following flow, ultimately hitting the WARN_ON():
kvm_timer_vcpu_reset()
if (timer->enabled)
kvm_timer_update_irq()
if (!userspace_irqchip())
ret = kvm_vgic_inject_irq()
ret = vgic_lazy_init()
if (unlikely(!vgic_initialized(kvm)))
if (kvm->arch.vgic.vgic_model !=
KVM_DEV_TYPE_ARM_VGIC_V2)
return -EBUSY;
WARN_ON(ret);
Theoretically, since userspace_irqchip_in_use's functionality can be
simply replaced by '!irqchip_in_kernel()', get rid of the static key
to avoid the mismanagement, which also helps with the syzbot issue.
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Don't retire aborted MMIO instruction
Returning an abort to the guest for an unsupported MMIO access is a
documented feature of the KVM UAPI. Nevertheless, it's clear that this
plumbing has seen limited testing, since userspace can trivially cause a
WARN in the MMIO return:
WARNING: CPU: 0 PID: 30558 at arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536
Call trace:
kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536
kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133
kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487
__do_sys_ioctl fs/ioctl.c:51 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x1e0/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712
el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
The splat is complaining that KVM is advancing PC while an exception is
pending, i.e. that KVM is retiring the MMIO instruction despite a
pending synchronous external abort. Womp womp.
Fix the glaring UAPI bug by skipping over all the MMIO emulation in
case there is a pending synchronous exception. Note that while userspace
is capable of pending an asynchronous exception (SError, IRQ, or FIQ),
it is still safe to retire the MMIO instruction in this case as (1) they
are by definition asynchronous, and (2) KVM relies on hardware support
for pending/delivering these exceptions instead of the software state
machine for advancing PC.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix potential out-of-bound accesses for Extigy and Mbox devices
A bogus device can provide a bNumConfigurations value that exceeds the
initial value used in usb_get_configuration for allocating dev->config.
This can lead to out-of-bounds accesses later, e.g. in
usb_destroy_configuration.
In the Linux kernel, the following vulnerability has been resolved:
xen: Fix the issue of resource not being properly released in xenbus_dev_probe()
This patch fixes an issue in the function xenbus_dev_probe(). In the
xenbus_dev_probe() function, within the if (err) branch at line 313, the
program incorrectly returns err directly without releasing the resources
allocated by err = drv->probe(dev, id). As the return value is non-zero,
the upper layers assume the processing logic has failed. However, the probe
operation was performed earlier without a corresponding remove operation.
Since the probe actually allocates resources, failing to perform the remove
operation could lead to problems.
To fix this issue, we followed the resource release logic of the
xenbus_dev_remove() function by adding a new block fail_remove before the
fail_put block. After entering the branch if (err) at line 313, the
function will use a goto statement to jump to the fail_remove block,
ensuring that the previously acquired resources are correctly released,
thus preventing the reference count leak.
This bug was identified by an experimental static analysis tool developed
by our team. The tool specializes in analyzing reference count operations
and detecting potential issues where resources are not properly managed.
In this case, the tool flagged the missing release operation as a
potential problem, which led to the development of this patch.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: imx-audmix: Add NULL check in imx_audmix_probe
devm_kasprintf() can return a NULL pointer on failure,but this
returned value in imx_audmix_probe() is not checked.
Add NULL check in imx_audmix_probe(), to handle kernel NULL
pointer dereference error.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix null check for pipe_ctx->plane_state in hwss_setup_dpp
This commit addresses a null pointer dereference issue in
hwss_setup_dpp(). The issue could occur when pipe_ctx->plane_state is
null. The fix adds a check to ensure `pipe_ctx->plane_state` is not null
before accessing. This prevents a null pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix null check for pipe_ctx->plane_state in dcn20_program_pipe
This commit addresses a null pointer dereference issue in
dcn20_program_pipe(). Previously, commit 8e4ed3cf1642 ("drm/amd/display:
Add null check for pipe_ctx->plane_state in dcn20_program_pipe")
partially fixed the null pointer dereference issue. However, in
dcn20_update_dchubp_dpp(), the variable pipe_ctx is passed in, and
plane_state is accessed again through pipe_ctx. Multiple if statements
directly call attributes of plane_state, leading to potential null
pointer dereference issues. This patch adds necessary null checks to
ensure stability.
In the Linux kernel, the following vulnerability has been resolved:
firmware_loader: Fix possible resource leak in fw_log_firmware_info()
The alg instance should be released under the exception path, otherwise
there may be resource leak here.
To mitigate this, free the alg instance with crypto_free_shash when kmalloc
fails.