CVE-2026-74646: Linux kernel · misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix has been implemented in the Linux kernel to address this issue by ensuring the fl->lock is taken when moving mmaps on interrupted invoke operations. Users should apply the official kernel updates that include this patch. Since this is not a cloud service, remediation depends on applying the updated kernel version from the vendor or distribution. Patch status is not explicitly confirmed in the provided data; users should consult their Linux distribution's security advisories for the exact fixed versions and update accordingly.
Description
In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke When an invoke is interrupted by a signal, wait_for_completion_interruptible() returns -ERESTARTSYS and fastrpc_internal_invoke() moves every buffer from fl->mmaps onto cctx->invoke_interrupted_mmaps. This list_del()/list_add_tail() walk runs without holding fl->lock, the lock that serialises fl->mmaps in fastrpc_req_mmap() and fastrpc_req_munmap() everywhere else. Take fl->lock around the move, matching every other fl->mmaps accessor.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74646 (opens in a new tab)
- git.kernel.org/stable/c/3f265e405e5ef85030c3777262e18bb556bc8724 (opens in a new tab)
- git.kernel.org/stable/c/a902fe1f80f58a2335b6be1131866f827ec44d1a (opens in a new tab)
- git.kernel.org/stable/c/af6345159abcbaa550518f31990d2a9558c2d369 (opens in a new tab)
- git.kernel.org/stable/c/b85a0e91d7d6cd06a53c881a46f749cfcef416a2 (opens in a new tab)
- git.kernel.org/stable/c/efd02f8d1a7449f15809bc18d3cd41aafea75d7e (opens in a new tab)
- ubuntu.com/security/CVE-2026-74646 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74646 (opens in a new tab)