CVE-2026-98230EPSS p1.6%
CVE-2026-98230CVE-2026-98230
Description
In the Linux kernel, the following vulnerability has been resolved:
xfrm: use hlist_del_init_rcu for state_cache and state_cache_input
Commit 14acf9652e56 ("xfrm: defensively unhash xfrm_state lists in
__xfrm_state_delete") converted bydst/bysrc/byseq/byspi from
hlist_del_rcu() to hlist_del_init_rcu() so that a second
__xfrm_state_delete() on the same object becomes a no-op rather than a
write through LIST_POISON pprev. It missed state_cache and
state_cache_input, which kept hlist_del_rcu():
- hlist_del_rcu() leaves pprev = LIST_POISON2 (non-NULL), so
hlist_unhashed() returns false.
- hlist_del_init_rcu() leaves pprev = NULL, so hlist_unhashed()
returns true.
A second __xfrm_state_delete() therefore enters __hlist_del() on the
already-deleted state_cache/state_cache_input nodes and does
WRITE_ONCE(*pprev, next) through LIST_POISON2 — a write use-after-free
once the slab is reused. The corruption can in turn cause a subsequent
hlist_for_each_entry_rcu traversal to follow a dangl
Scoring
| CVSS | 7.0 () |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 0.12% probability of exploitation · percentile 1.6% · 2026-10-10T12:00:23Z |
| Last modified | 2026-10-07 |