CVE-2026-64563

rhashtable: clear stale iter->p on table restart

State: Published
Severity: 7.8 High
Published: Aug 4, 2026
Updated: Oct 19, 2026
Reserved: Jul 19, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-416 Use After Free

Affected Products

Product	Versions
LinuxLinux	5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before ba510b5e9fe396497d31162acb579f210adfe6c8Affected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before a0406c40c6638c5ae50257db6297b2fba6c9ba16Affected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 0955b65c2b47c30b439e2cf1b1e375073aa0413aAffected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before c39643ad99fea749be50615550e8f0e6d6e60694Affected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 042fda5c088015f18838e5c692659a7be60aeb26Affected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 3ff7c1dbf722cf3fa538672452ba182318e0fcc3Affected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3Affected 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 8173f7e2ce67e6ca1d4763f3da14e5b01ce77456Affected
LinuxLinux	4.18Affected before 4.18Not affected 5.10.265 through 5.10.Not affected 5.15.216 through 5.15.Not affected 6.1.183 through 6.1.Not affected 6.6.151 through 6.6.Not affected 6.12.103 through 6.12.Not affected 6.18.42 through 6.18.Not affected 7.1.6 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before ba510b5e9fe396497d31162acb579f210adfe6c8Affected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before a0406c40c6638c5ae50257db6297b2fba6c9ba16Affected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 0955b65c2b47c30b439e2cf1b1e375073aa0413aAffected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before c39643ad99fea749be50615550e8f0e6d6e60694Affected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 042fda5c088015f18838e5c692659a7be60aeb26Affected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 3ff7c1dbf722cf3fa538672452ba182318e0fcc3Affected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3Affected
5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 to before 8173f7e2ce67e6ca1d4763f3da14e5b01ce77456Affected

LinuxLinux

4.18Affected
before 4.18Not affected
5.10.265 through 5.10.*Not affected
5.15.216 through 5.15.*Not affected
6.1.183 through 6.1.*Not affected
6.6.151 through 6.6.*Not affected
6.12.103 through 6.12.*Not affected
6.18.42 through 6.18.*Not affected
7.1.6 through 7.1.*Not affected
7.2 and laterNot affected

References

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