MGASA-2021-0397

This kernel update is based on upstream 5.10.56 and fixes at least the following security issues:

In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack (CVE-2021-34556).

In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because a certain preempting store operation does not necessarily occur before a store operation that has an attacker-controlled value (CVE-2021-35477).

Other fixes in this update: - btrfs: fix lost inode on log replay after mix of fsync, rename and inode eviction - btrfs: fix race causing unnecessary inode logging during link and rename - watchdog: iTCO_wdt: Fix detection of SMI-off case (fixes sporadic reboots on some systems) - Revert "ACPICA: Fix memory leak caused by _CID repair function", fixing boot failures on some systems - fix another ACPI issue causing some systems to boot slowly or not at all after kernel 5.10.50 - revert: 'scsi: sr: Return appropriate error code when disk is ejected' (fixes DVD opening on resume from suspend or standby, mga #29262) - Revert "usb: renesas-xhci: Fix handling of unknown ROM state" (fixes renesas usb pci stopped working, mga #29285) - Revert "drm/i915: Propagate errors on awaiting already signaled fences" and "drm/i915/gem: Asynchronous cmdparser" (fixes an issue where an app hang can cause X server to hang)

For other upstream fixes, see the referenced changelogs.