CVE-2026-74631: Linux kernel · net: smc: fix splice entry lifetime imbalance in smc_rx_splice
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.4 High : upgrade to 6.8.0-1036.39 soon.
Data as of 28 Oct 2026, 01:00 UTC
- Patch
- Available – fixed in 6.8.0-1036.39
CVSS:3.1/AV:L/AC:L/PR:N/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
Upgrade the Ubuntu linux-nvidia-tegra package to 6.8.0-1036.39.
Patches and advisories
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.
Description
In the Linux kernel, the following vulnerability has been resolved: net: smc: fix splice entry lifetime imbalance in smc_rx_splice smc_rx_splice() passes pages to splice_to_pipe() before taking the references that cover the lifetime of each splice entry. In the VM-backed RMB path, splice_to_pipe() may drop unqueued entries through smc_rx_spd_release(), while queued entries are released later via the pipe buffer callback. The old post-splice accounting also derives the number of queued VM pages from an offset mutated while building the descriptor, and a multi-page splice pairs one sock_hold() with multiple sock_put() calls. Take the page and socket references for every candidate entry before splice_to_pipe(), and drop the matching private state, page reference, and socket reference from smc_rx_spd_release() for entries that never get queued. This fixes a refcount imbalance that can underflow page refcounts and trigger a use-after-free.
References
- ubuntu.com/security/CVE-2026-74631 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74631 (opens in a new tab)
- git.kernel.org/stable/c/4515c78f4d9fd577270f012efeb062ea58b3682d (opens in a new tab)
- git.kernel.org/stable/c/0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0 (opens in a new tab)
- git.kernel.org/stable/c/c841789e456ec6751342fa800639ce8e82ff0e6b (opens in a new tab)
- git.kernel.org/stable/c/af02c67ce654356c58db20a0bb2db33ace3b07a8 (opens in a new tab)
- git.kernel.org/stable/c/07ad246529d136d5ef441d5ab4c305d132ff3090 (opens in a new tab)
- git.kernel.org/stable/c/7ddc7af2ae7fc5a0c0635b245c0824c8b76de5cb (opens in a new tab)
- git.kernel.org/stable/c/5d9686af2976741bbd79b150d1c9e60b81e7f12e (opens in a new tab)
- git.kernel.org/stable/c/ca8342b5fc24c249fdb998468f6a168b457c67e5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)