PT-2021-8266 · Linux+2 · Linux Kernel+2
Chris Riedl
·
Published
2021-02-08
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Updated
2024-10-31
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CVE-2021-47034
CVSS v3.1
4.4
Medium
| Vector | AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel versions prior to 5.10.0-rc5-01361-ge3c1b78c8440-dirty
Description
The issue is related to the
radix set pte at() function in the Linux kernel, which does not properly order the update of the Page Table Entry (PTE) with subsequent accesses. This can lead to spurious faults when accessing kernel memory. The problem is exacerbated by the use of put user asm goto() for code patching, which can obscure the resulting fault. A reliable way to reproduce the issue has been suggested by Chris Riedl, involving the use of debugfs and tracing. The vulnerability can cause the kernel to crash, resulting in a denial-of-service.Recommendations
To resolve the issue, update the Linux kernel to a version that includes the fix for the
powerpc/64s: Fix pte update for kernel memory on radix vulnerability. Specifically, update to a version later than 5.10.0-rc5-01361-ge3c1b78c8440-dirty. As a temporary workaround, consider disabling code patching with Strict RWX on radix or restricting access to the vulnerable radix set pte at() function until a patch is available.Fix
Resource Exhaustion
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Weakness Enumeration
Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Suse