Описание
In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: avoid in-place decrypt on shared skb frags
MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP
marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(),
so later paths that may modify packet data can first make a private
copy. The IPv4/IPv6 datagram append paths did not set this flag when
splicing pages into UDP skbs.
That leaves an ESP-in-UDP packet made from shared pipe pages looking
like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW
fast path for uncloned skbs without a frag_list and decrypts in place
over data that is not owned privately by the skb.
Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching
TCP. Also make ESP input fall back to skb_cow_data() when the flag is
present, so ESP does not decrypt externally backed frags in place.
Private nonlinear skb frags still use the existing fast path.
This intentionally does not change ESP output. In esp_output_head(),
the path that appends the ESP trailer to existing skb tailroom without
calling skb_cow_data() is not reachable for nonlinear skbs:
skb_tailroom() returns zero when skb->data_len is nonzero, while ESP
tailen is positive. Thus ESP output will either use the separate
destination-frag path or fall back to skb_cow_data().
A flaw was found in the Linux kernel's xfrm-ESP and RxRPC subsystems. Unsafe in-place cryptographic processing of shared socket buffer fragments allows a low-privileged local attacker to corrupt page-cache contents of readable files, including sensitive system files, and gain root privileges. The xfrm-ESP variant requires unprivileged user or network namespace creation, while the RxRPC variant depends on the rxrpc module being available on the target system.
Отчет
This issue is classified as Important, rather than Critical severity, because exploitation requires local access to the system. A low-privileged local attacker can exploit this flaw in the Linux kernel's xfrm-ESP and RxRPC subsystems to gain root privileges by overwriting sensitive system files. Exploitation does not require user interaction, potentially resulting in full compromise of confidentiality, integrity, and availability.
Меры по смягчению последствий
See the security bulletin for a detailed mitigation procedure.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| NVIDIA for RHEL 10 | kernel | Fixed | RHSA-2026:17795 | 15.05.2026 |
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2026:16062 | 11.05.2026 |
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2026:19074 | 19.05.2026 |
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2026:19569 | 20.05.2026 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | kernel | Fixed | RHSA-2026:16314 | 12.05.2026 |
| Red Hat Enterprise Linux 8 | kernel-rt | Fixed | RHSA-2026:16196 | 12.05.2026 |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2026:16195 | 12.05.2026 |
Показывать по
Дополнительная информация
Статус:
EPSS
7.8 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP...
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change E
xfrm: esp: avoid in-place decrypt on shared skb frags
In the Linux kernel, the following vulnerability has been resolved: x ...
Security update for the Linux Kernel (Live Patch 31 for SUSE Linux Enterprise 15 SP5)
EPSS
7.8 High
CVSS3