CVE-2026-46300

Summary

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned or page-cache-backed frags, but the shared-frag marker is currently lost. That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags. Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors.

Impact & exploitability

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

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641cPatch
• https://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987Patch
• https://git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111Patch
• https://git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414aPatch
• https://git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34ePatch
• https://git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0Patch
• https://git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5Patch
• https://git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3Patch