CVE-2021-47228 Affecting kernel-default package, versions <5.3.18-150300.59.164.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-SLES153-KERNELDEFAULT-7362918
- published25 Jun 2024
- disclosed24 Jun 2024
Introduced: 24 Jun 2024
CVE-2021-47228 (opens in a new tab)How to fix?
Upgrade SLES:15.3 kernel-default to version 5.3.18-150300.59.164.1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-default package and not the kernel-default package as distributed by SLES.
See How to fix? for SLES:15.3 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
x86/ioremap: Map EFI-reserved memory as encrypted for SEV
Some drivers require memory that is marked as EFI boot services data. In order for this memory to not be re-used by the kernel after ExitBootServices(), efi_mem_reserve() is used to preserve it by inserting a new EFI memory descriptor and marking it with the EFI_MEMORY_RUNTIME attribute.
Under SEV, memory marked with the EFI_MEMORY_RUNTIME attribute needs to be mapped encrypted by Linux, otherwise the kernel might crash at boot like below:
EFI Variables Facility v0.08 2004-May-17 general protection fault, probably for non-canonical address 0x3597688770a868b2: 0000 [#1] SMP NOPTI CPU: 13 PID: 1 Comm: swapper/0 Not tainted 5.12.4-2-default #1 openSUSE Tumbleweed Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:efi_mokvar_entry_next [...] Call Trace: efi_mokvar_sysfs_init ? efi_mokvar_table_init do_one_initcall ? __kmalloc kernel_init_freeable ? rest_init kernel_init ret_from_fork
Expand the __ioremap_check_other() function to additionally check for this other type of boot data reserved at runtime and indicate that it should be mapped encrypted for an SEV guest.
[ bp: Massage commit message. ]
References
- https://www.suse.com/security/cve/CVE-2021-47228.html
- https://bugzilla.suse.com/1224826
- https://git.kernel.org/stable/c/208bb686e7fa7fff16e8fa78ff0db34aa9acdbd7
- https://git.kernel.org/stable/c/8d651ee9c71bb12fc0c8eb2786b66cbe5aa3e43b
- https://git.kernel.org/stable/c/b7a05aba39f733ec337c5b952e112dd2dc4fc404