Bug 2265833 (CVE-2024-26603)
| Summary: | CVE-2024-26603 kernel: x86/fpu: Stop relying on userspace for info to fault in xsave buffer that cause loop forever | ||
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| Product: | [Other] Security Response | Reporter: | Mauro Matteo Cascella <mcascell> |
| Component: | vulnerability | Assignee: | Product Security <prodsec-ir-bot> |
| Status: | NEW --- | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | unspecified | CC: | acaringi, allarkin, aquini, bhu, chwhite, cye, cyin, dbohanno, debarbos, dfreiber, drow, dvlasenk, esandeen, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kyoshida, ldoskova, lgoncalv, lzampier, mleitner, mmilgram, mstowell, nmurray, ptalbert, rparrazo, rrobaina, rvrbovsk, rysulliv, scweaver, sukulkar, tglozar, tyberry, vkumar, wcosta, williams, wmealing, ycote, ykopkova, zhijwang |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | kernel 6.1.79, kernel 6.6.18, kernel 6.7.6, kernel 6.8-rc4 | Doc Type: | If docs needed, set a value |
| Doc Text: |
A flaw was found in the Linux kernel's x86/fpu module, which revolves around an issue with relying on user space for critical information regarding the xsave buffer. In the affected scenario, the expected size of the user space buffer is derived from user-controlled data, specifically, fx_sw->xstate_size. By manipulating this value, an attacker could construct a malicious sigreturn frame where the indicated size is smaller than required by valid bits in fx_sw->xfeatures. Furthermore, the attacker could unmap portions of the fpu buffer in the user space, rendering them inaccessible to xrstor.
This manipulation leads to a situation where xrstor repeatedly attempts to restore and access an unmapped area, causing a fault. However, the fault_in_readable function erroneously succeeds because the accessed region, buf + fx_sw->xstate_size, remains within the mapped area. Consequently, the system enters a perpetual loop as xrstor continually retries the operation.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 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: | 2265834 | ||
| Bug Blocks: | 2267044 | ||
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Description
Mauro Matteo Cascella
2024-02-24 17:40:33 UTC
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 2265834] This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2024:3618 https://access.redhat.com/errata/RHSA-2024:3618 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2024:3627 https://access.redhat.com/errata/RHSA-2024:3627 The result of automatic check (that is developed by Alexander Larkin) for this CVE-2024-26603 is: CHECK Maybe valid. Check manually. with impact LOW (that is an approximation based on flags ; these flags parsed automatically based on patch data). Such automatic check happens only for Low/Moderates (and only when not from reporter, but parsing already existing CVE). Highs always checked manually (I check it myself and then we check it again in Remediation team). In rare cases some of the Moderates could be increased to High later. This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2024:9315 https://access.redhat.com/errata/RHSA-2024:9315 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2025:2490 https://access.redhat.com/errata/RHSA-2025:2490 |