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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 3599e6b3cc1ada96883d496a50a210d3afbb6987affected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641caffected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5affected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 78bf6b6bb19541d19fbda6242e7cfe2c682763c0affected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34eaffected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 3bd9e113d50034db99d7ef69fd8e5242d15e414aaffected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < 3884358a9286b17f389a72b1426fc4547c23c111affected
LinuxLinuxcef401de7be8c4e155c6746bfccf721a4fa5fab9 < f84eca5817390257cef78013d0112481c503b4a3affected
LinuxLinux3.9affected
LinuxLinux0 < 3.9unaffected
LinuxLinux5.10.257 <= 5.10.*unaffected
LinuxLinux5.15.208 <= 5.15.*unaffected
LinuxLinux6.1.174 <= 6.1.*unaffected
LinuxLinux6.6.141 <= 6.6.*unaffected
LinuxLinux6.12.91 <= 6.12.*unaffected
LinuxLinux6.18.33 <= 6.18.*unaffected
LinuxLinux7.0.10 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

kernel: “Fragnesia” is a variant of Dirty Frag vulnerability in the ESP/XFRM leading to Local Privilege Escalation (LPE) vulnerability in the Linux kernel

Additional References

References