An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer 'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm' device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system.
A buffer overflow flaw was found, in versions from 2.6.34 to 5.2.x, in the way Linux kernel's vhost functionality that translates virtqueue buffers to IOVs, logged the buffer descriptors during migration. A privileged guest user able to pass descriptors with invalid length to the host when migration is underway, could use this flaw to increase their privileges on the host.
In the Linux kernel through 5.2.14 on the powerpc platform, a local user can read vector registers of other users' processes via a Facility Unavailable exception. To exploit the venerability, a local user starts a transaction (via the hardware transactional memory instruction tbegin) and then accesses vector registers. At some point, the vector registers will be corrupted with the values from a different local Linux process because of a missing arch/powerpc/kernel/process.c check.
In the Linux kernel through 5.2.14 on the powerpc platform, a local user can read vector registers of other users' processes via an interrupt. To exploit the venerability, a local user starts a transaction (via the hardware transactional memory instruction tbegin) and then accesses vector registers. At some point, the vector registers will be corrupted with the values from a different local Linux process, because MSR_TM_ACTIVE is misused in arch/powerpc/kernel/process.c.
drivers/net/wireless/marvell/libertas/if_sdio.c in the Linux kernel 5.2.14 does not check the alloc_workqueue return value, leading to a NULL pointer dereference.