PT-2024-8982 · Linux+3 · Linux Kernel+3
David Hildenbrand
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Published
2024-05-24
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Updated
2024-11-27
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CVE-2021-47566
CVSS v3.1
7.8
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions:
Linux kernel versions prior to 5.15.0
Description:
The vulnerability is related to the proc/vmcore component of the Linux kernel. It is caused by a buffer overflow when clearing a user buffer, which can lead to a permissions violation. The issue can be triggered by copying the vmcore via "cp" with a virtio-mem device that registers a vmcore cb and has some logically unplugged memory inside an added Linux memory block. Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access Prevention (SMAP)" that can detect wrong access from the kernel to user buffers, triggering a permissions violation on wrong access. The vulnerability can cause a BUG and a page fault, leading to a crash.
Recommendations:
To resolve the issue, properly use the clear user() function when dealing with a user buffer, instead of memset. This can be achieved by updating the Linux kernel to a version that includes the fix for the proc/vmcore vulnerability.
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Memory Corruption
Buffer Overflow
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Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Red Os
Suse