CVE-2023-52759
Vulnerability Scoring
Status: Awaiting Analysis
Last updated: 🕣 21 Nov 2024, 08:40 UTC
Originally published on: 🕓 21 May 2024, 16:15 UTC
Time between publication and last update: 183 days
CVSS Release:
CVE-2023-52759: In the Linux kernel, the following vulnerability has been resolved: gfs2: ignore negated quota changes When lots of quota changes are made, there may be cases in which an inode's quota information is increased and then decreased, such as when blocks are added to a file, then deleted from it. If the timing is right, function do_qc can add pending quota changes to a transaction, then later, another call to do_qc can negate those changes, resulting in a net gain of 0. The quota_change information is recorded in the qc buffer (and qd element of the inode as well). The buffer is added to the transaction by the first call to do_qc, but a subsequent call changes the value from non-zero back to zero. At that point it's too late to remove the buffer_head from the transaction. Later, when the quota sync code is called, the zero-change qd element is discovered and flagged as an assert warning. If the fs is mounted with errors=panic, the kernel will panic. This is usually seen when files are truncated and the quota changes are negated by punch_hole/truncate which uses gfs2_quota_hold and gfs2_quota_unhold rather than block allocations that use gfs2_quota_lock and gfs2_quota_unlock which automatically do quota sync. This patch solves the problem by adding a check to qd_check_sync such that net-zero quota changes already added to the transaction are no longer deemed necessary to be synced, and skipped. In this case references are taken for the qd and the slot from do_qc so those need to be put. The normal sequence of events for a normal non-zero quota change is as follows: gfs2_quota_change do_qc qd_hold slot_hold Later, when the changes are to be synced: gfs2_quota_sync qd_fish qd_check_sync gets qd ref via lockref_get_not_dead do_sync do_qc(QC_SYNC) qd_put lockref_put_or_lock qd_unlock qd_put lockref_put_or_lock In the net-zero change case, we add a check to qd_check_sync so it puts the qd and slot references acquired in gfs2_quota_change and skip the unneeded sync.
The exploitability of CVE-2023-52759 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
No exploitability data is available for CVE-2023-52759.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2023-52759, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2023-52759, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.043% (probability of exploit)
EPSS Percentile: 11.87%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 88.13% of others.
Unknown
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