Description
In the Linux kernel, the following vulnerability has been resolved:

xfrm: fix compat ALLOCSPI request use-after-free

xfrm_state_netlink() builds the ALLOCSPI response with
dump_one_state(), which already calls alloc_compat() with the response
skb and header.

xfrm_alloc_userspi() then calls alloc_compat() again, but passes the
original request skb and its header. For a compat request, the
translator therefore interprets the 228-byte compat xfrm_userspi_info
as the 232-byte native layout and reads four bytes past the declared
payload. It also publishes the translated child through the request's
frag_list.

A multicast clone of the request shares skb_shared_info and can observe
that child. xfrm_user_rcv_msg() frees it after the request handler
returns, racing a compat receiver which may still be copying from it and
resulting in a use-after-free.

Remove the redundant conversion. The response keeps its correct compat
translation from dump_one_state(), and no child is attached to the
inbound request.
Published: 2026-10-06
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Tue, 06 Oct 2026 09:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: xfrm: fix compat ALLOCSPI request use-after-free xfrm_state_netlink() builds the ALLOCSPI response with dump_one_state(), which already calls alloc_compat() with the response skb and header. xfrm_alloc_userspi() then calls alloc_compat() again, but passes the original request skb and its header. For a compat request, the translator therefore interprets the 228-byte compat xfrm_userspi_info as the 232-byte native layout and reads four bytes past the declared payload. It also publishes the translated child through the request's frag_list. A multicast clone of the request shares skb_shared_info and can observe that child. xfrm_user_rcv_msg() frees it after the request handler returns, racing a compat receiver which may still be copying from it and resulting in a use-after-free. Remove the redundant conversion. The response keeps its correct compat translation from dump_one_state(), and no child is attached to the inbound request.
Title xfrm: fix compat ALLOCSPI request use-after-free
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-06T08:46:54.981Z

Reserved: 2026-09-25T10:25:14.344Z

Link: CVE-2026-98370

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-06T09:18:31.450

Modified: 2026-10-06T09:18:31.450

Link: CVE-2026-98370

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.