Riskcovery

CVE-2026-46300

net: skbuff: preserve shared-frag marker during coalescing

State
Published
Severity
7.8 High
Published
May 23, 2026
Updated
Oct 29, 2026
Reserved
May 13, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hredhat-SADP

Weaknesses

  • CWE-123 Write-what-where Condition
  • CWE-456 Missing Initialization of a Variable

Affected Products

ProductVersions
LinuxLinux
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 3599e6b3cc1ada96883d496a50a210d3afbb6987Affected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641cAffected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5Affected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 78bf6b6bb19541d19fbda6242e7cfe2c682763c0Affected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34eAffected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 3bd9e113d50034db99d7ef69fd8e5242d15e414aAffected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before 3884358a9286b17f389a72b1426fc4547c23c111Affected
  • cef401de7be8c4e155c6746bfccf721a4fa5fab9 to before f84eca5817390257cef78013d0112481c503b4a3Affected
LinuxLinux
  • 3.9Affected
  • before 3.9Not affected
  • 5.10.257 through 5.10.*Not affected
  • 5.15.208 through 5.15.*Not affected
  • 6.1.174 through 6.1.*Not affected
  • 6.6.141 through 6.6.*Not affected
  • 6.12.91 through 6.12.*Not affected
  • 6.18.33 through 6.18.*Not affected
  • 7.0.10 through 7.0.*Not affected
  • 7.1 and laterNot affected

References

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