PT-2024-11095 · Linux+2 · Linux Kernel+2
Hugh Dickins
·
Published
2021-05-14
·
Updated
2024-12-26
·
CVE-2021-46988
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The issue arises when userspace issues a UFFD ioctl, which calls into
shmem mfill atomic pte(). If the copy from user() fails after successfully accounting blocks and allocating a page with shmem alloc page(), the error code -ENOENT is returned without releasing the allocated page. This can lead to a situation where another process fills up the tmpfs, causing shmem mfill atomic pte() to fail when retried, resulting in a BUG ON assertion failure because the page is not consumed. The fix involves detecting and releasing any "dangling" pages when accounting fails.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
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Weakness Enumeration
Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Suse