Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

habanalabs: fix UAF in export_dmabuf()

As soon as we'd inserted a file reference into descriptor table, another thread could close it. That's fine for the case when all we are doing is returning that descriptor to userland (it's a race, but it's a userland race and there's nothing the kernel can do about it). However, if we follow fd_install() with any kind of access to objects that would be destroyed on close (be it the struct file itself or anything destroyed by its ->release()), we have a UAF.

dma_buf_fd() is a combination of reserving a descriptor and fd_install(). habanalabs export_dmabuf() calls it and then proceeds to access the objects destroyed on close. In particular, it grabs an extra reference to another struct file that will be dropped as part of ->release() for ours; that "will be" is actually "might have already been".

Fix that by reserving descriptor before anything else and do fd_install() only when everything had been set up. As a side benefit, we no longer have the failure exit with file already created, but reference to underlying file (as well as ->dmabuf_export_cnt, etc.) not grabbed yet; unlike dma_buf_fd(), fd_install() can't fail.

Affected: Ubuntu:24.04:LTS: linux, Ubuntu:24.04:LTS: linux-raspi

It was discovered that improper initialization of CPU cache memory could allow a local attacker with hypervisor access to overwrite SEV-SNP guest memory resulting in loss of data integrity. (CVE-2024-36331)

Oleksii Oleksenko, Cedric Fournet, Jana Hofmann, Boris Köpf, Stavros Volos, and Flavien Solt discovered that some AMD processors may allow an attacker to infer data from previous stores, potentially resulting in the leakage of privileged information. A local attacker could possibly use this to expose sensitive information. (CVE-2024-36350, CVE-2024-36357)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM32 architecture; - ARM64 architecture; - MIPS architecture; - PA-RISC architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - x86 architecture; - Block layer subsystem; - Cryptographic API; - Compute Acceleration Framework; - ACPI drivers; - Serial ATA and Parallel ATA drivers; - ATM drivers; - Drivers core; - ATA over ethernet (AOE) driver; - DRBD Distributed Replicated Block Device drivers; - Network block device driver; - Ublk userspace block driver; - Bluetooth drivers; - Bus devices; - Character device driver; - TPM device driver; - Clock framework and drivers; - Data acquisition framework and drivers; - CPU frequency scaling framework; - Hardware cryp…