PT-2021-8166 · Linux+3 · Linux Kernel+3
Chris Murphy
·
Published
2021-11-16
·
Updated
2024-11-01
·
CVE-2021-47189
CVSS v3.1
6.3
Medium
| Vector | AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The issue is related to a race condition in the btrfs component of the Linux kernel, specifically between normal and ordered work functions. This can lead to crashes on ARM64 systems when
async chunk::inode is seen as non-null in async cow submit, causing submit compressed extents to be called and resulting in a crash because async chunk::inode suddenly becomes NULL. The synchronization between normal and ordered functions is done via the WORK DONE BIT, but the used bitops do not guarantee any ordering. To fix this, barrier calls are added to ensure that all accesses preceding the setting of WORK DONE BIT are strictly ordered before setting the flag, and a read barrier is added after reading WORK DONE BIT in run ordered work to ensure subsequent loads are strictly ordered after reading the bit.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
Race Condition
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Weakness Enumeration
Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Red Os
Suse