Bug 1903126 (CVE-2020-28974)
| Summary: | CVE-2020-28974 kernel: slab-out-of-bounds read in fbcon | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | msiddiqu |
| 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, bhu, blc, bmasney, brdeoliv, bskeggs, dhoward, dramseur, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, itamar, jarodwilson, jeremy, jforbes, jglisse, jhunter, jlelli, jonathan, josef, jross, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, kmitts, lgoncalv, linville, masami256, mchehab, mcressma, mgala, mjg59, mjudeiki, mlangsdo, mrehak, nmurray, ptalbert, qzhao, rkeshri, rt-maint, rvrbovsk, steved, walters, williams, yozone |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: |
An out-of-bounds (OOB) SLAB memory access flaw was found in the Linux kernel's fbcon driver module. A bounds check failure allows a local attacker with special user privileges to gain access to out-of-bounds memory, leading to a system crash or leaking of internal kernel information. The highest threat from this vulnerability is to system availability.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2021-05-18 20:37:41 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: | 1903128, 1903934, 1903935, 1903936, 1903937, 1903938, 1940053 | ||
| Bug Blocks: | 1895876 | ||
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Description
msiddiqu
2020-12-01 12:03:24 UTC
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1903128] This was fixed for Fedora with the 5.9.7 stable kernel updates. Acknowledgments: Name: Yuan Ming <yuanmingbuaa@gmail com> (Tsinghua University) Mitigation: Add 'nomodeset' option as kernel boot parameter to disable frame buffering in /etc/default/grub, and run 'grub2-mkconfig -o /boot/grub2/grub.cfg' and reboot. ~~~ # cat /proc/cmdline BOOT_IMAGE=(hd0,msdos1)/vmlinuz-4.18.0-147.el8.x86_64 root=/dev/mapper/rhel_rhel8u2--1-root ro crashkernel=auto resume=/dev/mapper/rhel_rhel8u2--1-swap rd.lvm.lv=rhel_rhel8u2-1/root rd.lvm.lv=rhel_rhel8u2-1/swap nomodeset # ls -l /dev/fb* ls: cannot access '/dev/fb*': No such file or directory ~~~ The above said mitigation does not so effect for rhel6 kernel , and is only applicable for rhel7/8. *** Bug 1903934 has been marked as a duplicate of this bug. *** This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:1578 https://access.redhat.com/errata/RHSA-2021:1578 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:1739 https://access.redhat.com/errata/RHSA-2021:1739 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-2020-28974 |