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CVE-2026-90051

HIGHCVSS 7.8/10

Last modified

CVE-2026-90051 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: tcp: reject non zerocopy devmem tx Devmem tcp tx doesn't work without zero-copy, however it's not currently enforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked() will try the copy path and try to copy data from an iovec which consists of offsets into the dma-buf and would normally fail.

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: reject non zerocopy devmem tx Devmem tcp tx doesn't work without zero-copy, however it's not currently enforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked() will try the copy path and try to copy data from an iovec which consists of offsets into the dma-buf and would normally fail. Moreover, d9c56501c72fd ("net: tcp: block mixing readable and unreadable frags") relies on that and assumes that the devmem binding is present IFF we're using the zero-copy path, which can be used to mix net-iov and pages in a single skb, and break invariants. Let's reject devmem tx without zero-copy. Note, the parameter check the patch is modifying is too loose, we can create an io_uring request with dmabuf_id and all ZC flags, but which won't have the binding. We replace it with stricter validation.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= bd61848900bff597764238f3a8ec67c815cd316e, < 2151b2bcf6fcec52665f606eed20da068447f0b7; >= bd61848900bff597764238f3a8ec67c815cd316e, < b04326c7927af7048fd4e730f5770cca350d0a60; >= bd61848900bff597764238f3a8ec67c815cd316e, < 125755776bc6d4dd53eaf551c87e3d460625d638
LinuxLinux6.16

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-90051?
In the Linux kernel, the following vulnerability has been resolved: tcp: reject non zerocopy devmem tx Devmem tcp tx doesn't work without zero-copy, however it's not currently enforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked() will try the copy path and try to copy data from an iovec which consists of offsets into the dma-buf and would normally fail. Moreover, d9c56501c72fd ("net: tcp: block mixing readable and unreadable frags") relies on that and assumes that the devmem binding is present IFF we're using the zero-copy path, which can be used to mix net-iov and pages in a single skb, and break invariants. Let's reject devmem tx without zero-copy. Note, the parameter check the patch is modifying is too loose, we can create an io_uring request with dmabuf_id and all ZC flags, but which won't have the binding. We replace it with stricter validation.
How severe is CVE-2026-90051?
CVE-2026-90051 has a CVSS score of 7.8/10 (HIGH severity).
How do I fix CVE-2026-90051?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST