CVE-2026-99284
In the Linux kernel, the following vulnerability has been resolved: net: skbuff: propagate shared-frag marker in skb_zerocopy() skb_zerocopy() moves frag descr…
Impact
In the Linux kernel, the following vulnerability has been resolved: net: skbuff: propagate shared-frag marker in skb_zerocopy() skb_zerocopy() moves frag descriptors from @from into @to and takes a reference on each frag, but it does not copy skb_shinfo(from)->flags into skb_shinfo(to)->flags. A destination skb holding the same page-cache backed frags as the source therefore reports skb_has_shared_frag() as false. That breaks the invariant relied on by later in-place writers. ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(); with the marker lost, an skb that skb_zerocopy() built for nfnetlink_queue or for an openvswitch upcall is decrypted in place, letting an unprivileged user write into the page cache of a root-owned read-only file. Propagate SKBFL_SHARED_FRAG when frag descriptors are copied, as done for the other frag-transfer helpers.
Affected products · Linux
| Product | Affected versions |
|---|---|
| Linux | from af2806f8f90a150160be898cd85332459c83c5cb before 1c623e3cbf43f12dd4a72712079bfa247a9b8ba3 from af2806f8f90a150160be898cd85332459c83c5cb before d7d6ff98d5d1b400f02211f962ac32cc0020aeab from af2806f8f90a150160be898cd85332459c83c5cb before 1a9c180cd8435917b7516edfb1c9148032c28773 from af2806f8f90a150160be898cd85332459c83c5cb before 79dc34beb1fdb3da79753e51e15c68591a2561fe Versions 3.14, patch: 6.18.61 |
References
- NVD record
- CVE.org record
- GitHub advisory
- https://git.kernel.org/stable/c/1c623e3cbf43f12dd4a72712079bfa247a9b8ba3
- https://git.kernel.org/stable/c/d7d6ff98d5d1b400f02211f962ac32cc0020aeab
- https://git.kernel.org/stable/c/1a9c180cd8435917b7516edfb1c9148032c28773
- https://git.kernel.org/stable/c/79dc34beb1fdb3da79753e51e15c68591a2561fe
- https://github.com/advisories/GHSA-j3jv-p835-c5gh
- https://nvd.nist.gov/vuln/detail/CVE-2026-99284