CVE-2026-46300 net: skbuff: preserve shared-frag marker during coalescing
7.8 KEV Utnyttjas aktivt enligt CISA
Analys på rafaelpfister.ch
Tillverkarens beskrivning (engelska)
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. Referensdata
- Tillverkare
- Linux
- Berörda produkter
- Linux
- CVSS 3.1
- 7.8 (HIGH)
- Vektor
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- Typ av svaghet
- CWE-456: Missing Initialization of a Variable
- Publicerad
- 23 maj 2026
- I KEV-katalogen sedan
- 28 oktober 2026
- Tidsfrist amerikanska federala myndigheter
- 31 oktober 2026
