Linux: >> Linux Kernel >> 6.6.63 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix racy issue from session lookup and expire
Increment the session reference count within the lock for lookup to avoid
racy issue with session expire.
CVSS Score
8.1
EPSS Score
0.002
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_midi: fix MIDI Streaming descriptor lengths
While the MIDI jacks are configured correctly, and the MIDIStreaming
endpoint descriptors are filled with the correct information,
bNumEmbMIDIJack and bLength are set incorrectly in these descriptors.
This does not matter when the numbers of in and out ports are equal, but
when they differ the host will receive broken descriptors with
uninitialized stack memory leaking into the descriptor for whichever
value is smaller.
The precise meaning of "in" and "out" in the port counts is not clearly
defined and can be confusing. But elsewhere the driver consistently
uses this to match the USB meaning of IN and OUT viewed from the host,
so that "in" ports send data to the host and "out" ports receive data
from it.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: reallocate buf lists on upgrade
IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it
was created for legacy selected buffer and has been emptied. It violates
the requirement that most of the field should stay stable after publish.
Always reallocate it instead.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: core: flush gadget workqueue after device removal
device_del() can lead to new work being scheduled in gadget->work
workqueue. This is observed, for example, with the dwc3 driver with the
following call stack:
device_del()
gadget_unbind_driver()
usb_gadget_disconnect_locked()
dwc3_gadget_pullup()
dwc3_gadget_soft_disconnect()
usb_gadget_set_state()
schedule_work(&gadget->work)
Move flush_work() after device_del() to ensure the workqueue is cleaned
up.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
Move the conditional loading of hardware DR6 with the guest's DR6 value
out of the core .vcpu_run() loop to fix a bug where KVM can load hardware
with a stale vcpu->arch.dr6.
When the guest accesses a DR and host userspace isn't debugging the guest,
KVM disables DR interception and loads the guest's values into hardware on
VM-Enter and saves them on VM-Exit. This allows the guest to access DRs
at will, e.g. so that a sequence of DR accesses to configure a breakpoint
only generates one VM-Exit.
For DR0-DR3, the logic/behavior is identical between VMX and SVM, and also
identical between KVM_DEBUGREG_BP_ENABLED (userspace debugging the guest)
and KVM_DEBUGREG_WONT_EXIT (guest using DRs), and so KVM handles loading
DR0-DR3 in common code, _outside_ of the core kvm_x86_ops.vcpu_run() loop.
But for DR6, the guest's value doesn't need to be loaded into hardware for
KVM_DEBUGREG_BP_ENABLED, and SVM provides a dedicated VMCB field whereas
VMX requires software to manually load the guest value, and so loading the
guest's value into DR6 is handled by {svm,vmx}_vcpu_run(), i.e. is done
_inside_ the core run loop.
Unfortunately, saving the guest values on VM-Exit is initiated by common
x86, again outside of the core run loop. If the guest modifies DR6 (in
hardware, when DR interception is disabled), and then the next VM-Exit is
a fastpath VM-Exit, KVM will reload hardware DR6 with vcpu->arch.dr6 and
clobber the guest's actual value.
The bug shows up primarily with nested VMX because KVM handles the VMX
preemption timer in the fastpath, and the window between hardware DR6
being modified (in guest context) and DR6 being read by guest software is
orders of magnitude larger in a nested setup. E.g. in non-nested, the
VMX preemption timer would need to fire precisely between #DB injection
and the #DB handler's read of DR6, whereas with a KVM-on-KVM setup, the
window where hardware DR6 is "dirty" extends all the way from L1 writing
DR6 to VMRESUME (in L1).
L1's view:
==========
<L1 disables DR interception>
CPU 0/KVM-7289 [023] d.... 2925.640961: kvm_entry: vcpu 0
A: L1 Writes DR6
CPU 0/KVM-7289 [023] d.... 2925.640963: <hack>: Set DRs, DR6 = 0xffff0ff1
B: CPU 0/KVM-7289 [023] d.... 2925.640967: kvm_exit: vcpu 0 reason EXTERNAL_INTERRUPT intr_info 0x800000ec
D: L1 reads DR6, arch.dr6 = 0
CPU 0/KVM-7289 [023] d.... 2925.640969: <hack>: Sync DRs, DR6 = 0xffff0ff0
CPU 0/KVM-7289 [023] d.... 2925.640976: kvm_entry: vcpu 0
L2 reads DR6, L1 disables DR interception
CPU 0/KVM-7289 [023] d.... 2925.640980: kvm_exit: vcpu 0 reason DR_ACCESS info1 0x0000000000000216
CPU 0/KVM-7289 [023] d.... 2925.640983: kvm_entry: vcpu 0
CPU 0/KVM-7289 [023] d.... 2925.640983: <hack>: Set DRs, DR6 = 0xffff0ff0
L2 detects failure
CPU 0/KVM-7289 [023] d.... 2925.640987: kvm_exit: vcpu 0 reason HLT
L1 reads DR6 (confirms failure)
CPU 0/KVM-7289 [023] d.... 2925.640990: <hack>: Sync DRs, DR6 = 0xffff0ff0
L0's view:
==========
L2 reads DR6, arch.dr6 = 0
CPU 23/KVM-5046 [001] d.... 3410.005610: kvm_exit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
CPU 23/KVM-5046 [001] ..... 3410.005610: kvm_nested_vmexit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
L2 => L1 nested VM-Exit
CPU 23/KVM-5046 [001] ..... 3410.005610: kvm_nested_vmexit_inject: reason: DR_ACCESS ext_inf1: 0x0000000000000216
CPU 23/KVM-5046 [001] d.... 3410.005610: kvm_entry: vcpu 23
CPU 23/KVM-5046 [001] d.... 3410.005611: kvm_exit: vcpu 23 reason VMREAD
CPU 23/KVM-5046 [001] d.... 3410.005611: kvm_entry: vcpu 23
CPU 23/KVM-5046 [001] d.... 3410.
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
PCI: Avoid putting some root ports into D3 on TUXEDO Sirius Gen1
commit 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend") sets the
policy that all PCIe ports are allowed to use D3. When the system is
suspended if the port is not power manageable by the platform and won't be
used for wakeup via a PME this sets up the policy for these ports to go
into D3hot.
This policy generally makes sense from an OSPM perspective but it leads to
problems with wakeup from suspend on the TUXEDO Sirius 16 Gen 1 with a
specific old BIOS. This manifests as a system hang.
On the affected Device + BIOS combination, add a quirk for the root port of
the problematic controller to ensure that these root ports are not put into
D3hot at suspend.
This patch is based on
https://lore.kernel.org/linux-pci/20230708214457.1229-2-mario.limonciello@amd.com
but with the added condition both in the documentation and in the code to
apply only to the TUXEDO Sirius 16 Gen 1 with a specific old BIOS and only
the affected root ports.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-06
In the Linux kernel, the following vulnerability has been resolved:
block: don't revert iter for -EIOCBQUEUED
blkdev_read_iter() has a few odd checks, like gating the position and
count adjustment on whether or not the result is bigger-than-or-equal to
zero (where bigger than makes more sense), and not checking the return
value of blkdev_direct_IO() before doing an iov_iter_revert(). The
latter can lead to attempting to revert with a negative value, which
when passed to iov_iter_revert() as an unsigned value will lead to
throwing a WARN_ON() because unroll is bigger than MAX_RW_COUNT.
Be sane and don't revert for -EIOCBQUEUED, like what is done in other
spots.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-06
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE
There is a WARN_ON_ONCE to catch an unlikely situation when
domain_remove_dev_pasid can't find the `pasid`. In case it nevertheless
happens we must avoid using a NULL pointer.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-06
In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Stop active perfmon if it is being destroyed
If the active performance monitor (`v3d->active_perfmon`) is being
destroyed, stop it first. Currently, the active perfmon is not
stopped during destruction, leaving the `v3d->active_perfmon` pointer
stale. This can lead to undefined behavior and instability.
This patch ensures that the active perfmon is stopped before being
destroyed, aligning with the behavior introduced in commit
7d1fd3638ee3 ("drm/v3d: Stop the active perfmon before being destroyed").
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-06
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix the warning "__rxe_cleanup+0x12c/0x170 [rdma_rxe]"
The Call Trace is as below:
"
<TASK>
? show_regs.cold+0x1a/0x1f
? __rxe_cleanup+0x12c/0x170 [rdma_rxe]
? __warn+0x84/0xd0
? __rxe_cleanup+0x12c/0x170 [rdma_rxe]
? report_bug+0x105/0x180
? handle_bug+0x46/0x80
? exc_invalid_op+0x19/0x70
? asm_exc_invalid_op+0x1b/0x20
? __rxe_cleanup+0x12c/0x170 [rdma_rxe]
? __rxe_cleanup+0x124/0x170 [rdma_rxe]
rxe_destroy_qp.cold+0x24/0x29 [rdma_rxe]
ib_destroy_qp_user+0x118/0x190 [ib_core]
rdma_destroy_qp.cold+0x43/0x5e [rdma_cm]
rtrs_cq_qp_destroy.cold+0x1d/0x2b [rtrs_core]
rtrs_srv_close_work.cold+0x1b/0x31 [rtrs_server]
process_one_work+0x21d/0x3f0
worker_thread+0x4a/0x3c0
? process_one_work+0x3f0/0x3f0
kthread+0xf0/0x120
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x22/0x30
</TASK>
"
When too many rdma resources are allocated, rxe needs more time to
handle these rdma resources. Sometimes with the current timeout, rxe
can not release the rdma resources correctly.
Compared with other rdma drivers, a bigger timeout is used.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-06