In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix the missing xa_store error check xa_store() can fail, it return xa_err(-EINVAL) if the entry cannot be stored in an XArray, or xa_err(-ENOMEM) if memory allocation failed, so check error for xa_store() to fix it.

In the Linux kernel, the following vulnerability has been resolved: virtio_pmem: Check device status before requesting flush If a pmem device is in a bad status, the driver side could wait for host ack forever in virtio_pmem_flush(), causing the system to hang. So add a status check in the beginning of virtio_pmem_flush() to return early if the device is not activated.

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix "in-kernel MMIO" check TDX only supports kernel-initiated MMIO operations. The handle_mmio() function checks if the #VE exception occurred in the kernel and rejects the operation if it did not. However, userspace can deceive the kernel into performing MMIO on its behalf. For example, if userspace can point a syscall to an MMIO address, syscall does get_user() or put_user() on it, triggering MMIO #VE. The kernel will treat the #VE as in-kernel MMIO. Ensure that the target MMIO address is within the kernel before decoding instruction.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. When Xen is out-of-memory, allocation of new event channels will result in crashing the host rather than reporting an error. Xen versions 4.10 and later are affected. All architectures are affected. The default configuration, when guests are created with xl/libxl, is not vulnerable, because of the default event-channel limit.