DLA-3404-1

A flaw use after free in the Linux kernel integrated infrared receiver/transceiver driver was found in the way user detaching rc device. A local user could use this flaw to crash the system or potentially escalate their privileges on the system.

A flaw was found in KVM. When calling the KVM_GET_DEBUGREGS ioctl, on 32-bit systems, there might be some uninitialized portions of the kvm_debugregs structure that could be copied to userspace, causing an information leak.

A use-after-free flaw was found in xgene_hwmon_remove in drivers/hwmon/xgene-hwmon.c in the Hardware Monitoring Linux Kernel Driver (xgene-hwmon). This flaw could allow a local attacker to crash the system due to a race problem. This vulnerability could even lead to a kernel information leak problem.

The Linux kernel allows userspace processes to enable mitigations by calling prctl with PR_SET_SPECULATION_CTRL which disables the speculation feature as well as by using seccomp. We had noticed that on VMs of at least one major cloud provider, the kernel still left the victim process exposed to attacks in some cases even after enabling the spectre-BTI mitigation with prctl. The same behavior can be observed on a bare-metal machine when forcing the mitigation to IBRS on boot command line. This happened because when plain IBRS was enabled (not enhanced IBRS), the kernel had some logic that determined that STIBP was not needed. The IBRS bit implicitly protects against cross-thread branch target injection. However, with legacy IBRS, the IBRS bit was cleared on returning to userspace, due to performance reasons, which disabled the implicit STIBP and left userspace threads vulnerable to cross-thread branch target injection against which STIBP protects.

An out-of-bounds write vulnerability was found in the Linux kernel's SLIMpro I2C device driver. The userspace "data->block[0]" variable was not capped to a number between 0-255 and was used as the size of a memcpy, possibly writing beyond the end of dma_buffer. This flaw could allow a local privileged user to crash the system or potentially achieve code execution.

In the Linux kernel before 5.19, drivers/gpu/drm/arm/malidp_planes.c misinterprets the get_sg_table return value (expects it to be NULL in the error case, whereas it is actually an error pointer).