Bug 2013242 (CVE-2021-20321)
| Summary: | CVE-2021-20321 kernel: In Overlayfs missing a check for a negative dentry before calling vfs_rename() | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | Alex <allarkin> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED ERRATA | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | acaringi, adscvr, airlied, alciregi, bhu, brdeoliv, bskeggs, chwhite, crwood, dhoward, dvlasenk, eshatokhin, fhrbata, fpacheco, hdegoede, hkrzesin, jarod, jarodwilson, jburrell, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mszeredi, nmurray, ptalbert, qzhao, rvrbovsk, steved, vkumar, walters, williams |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | kernel 5.15-rc5 | Doc Type: | If docs needed, set a value |
| Doc Text: |
A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2022-05-11 11:16:31 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 2010887, 2011181, 2013304, 2013305, 2013317, 2013318, 2013713, 2016378, 2026897 | ||
| Bug Blocks: | 2011920, 2013544 | ||
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:5241 https://access.redhat.com/errata/RHSA-2021:5241 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:5227 https://access.redhat.com/errata/RHSA-2021:5227 This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2021-20321 |
An attacker with a low-privileged user on a Linux machine with an overlay mount can escalate his privileges up to root when performing rename in specific way with this overlayfs. Reference: a295aef603e1 ("ovl: fix missing negative dentry check in ovl_rename()")