CVE Catalog

CVE-2026-64563

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel's rhashtable library, there is a use-after-free vulnerability during table restart. When the table is freed during resize, the iterator does not clear iter->p, leading to a dereference of freed memory in rhashtable_walk_next(). This affects netlink_diag and TIPC.

Risk Assessment

The vulnerability can lead to kernel panic or potential privilege escalation, posing a serious threat to system stability and security.

Recommendation

Apply the official Linux kernel patch that clears iter->p on table restart, and update to a patched kernel version.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: rhashtable: clear stale iter->p on table restart rhashtable_walk_start_check() has two restart paths when resuming a walk. When iter->walker.tbl is valid, it re-validates iter->p against the table and sets iter->p = NULL if the object is gone. When iter->walker.tbl is NULL (table was freed during resize), it resets slot and skip but forgets to clear iter->p. rhashtable_walk_next() then dereferences the stale iter->p, reading freed memory. This is a use-after-free. Any caller that does multi-fragment rhashtable walks across walk_stop/walk_start boundaries is affected. Concrete cases include netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC (tipc_nl_sk_walk in net/tipc/socket.c). Crash stack (netlink_diag): BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0 Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080) Call Trace: rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016) __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122) netlink_diag_dump+0xc2/0x240 netlink_dump+0x5bc/0x1270 netlink_recvmsg+0x7a3/0x980 sock_recvmsg+0x1bc/0x200 __sys_recvfrom+0x1d4/0x2c0

Vulnerability data from NVD (NIST) · CISA KEV · EPSS