netfilter: nft_ct: fix use-after-free in timeout object destroy (Linux Linux)

CVE-2026-31665
HIGH 7.8

At a glance

Source
NVD
EPSS
EPSS 0.12 % · percentile 2 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_ct: fix use-after-free in timeout object destroy nft_ct_timeout_obj_destroy() frees the timeout object with kfree() immediately after nf_ct_untimeout(), without waiting for an RCU grace period. Concurrent packet processing on other CPUs may still hold RCU-protected references to the timeout object obtained via rcu_dereference() in nf_ct_timeout_data(). Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer freeing until after an RCU grace period, matching the approach already used in nfnetlink_cttimeout.c. KASAN report: BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0 Read of size 4 at addr ffff8881035fe19c by task exploit/80 Call Trace: nf_conntrack_tcp_packet+0x1381/0x29d0 nf_conntrack_in+0x612/0x8b0 nf_hook_slow+0x70/0x100 __ip_local_out+0x1b2/0x210 tcp_sendmsg_locked+0x722/0x1580 __sys_sendto+0x2d8/0x320 Allocated by task 75: nft_ct_timeout_obj_init+0xf6/0x290 nft_obj_init+0x107/0x1b0 nf_tables_newobj+0x680/0x9c0 nfnetlink_rcv_batch+0xc29/0xe00 Freed by task 26: nft_obj_destroy+0x3f/0xa0 nf_tables_trans_destroy_work+0x51c/0x5c0 process_one_work+0x2c4/0x5a0

Weaknesses (CWE)

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 7e0b2b57f01d183e1c84114f1f2287737358d748 < c458fc1c278a65ad5381083121d39a479973ebed ; affected 7e0b2b57f01d183e1c84114f1f2287737358d748 < c581e5c8f2b59158f62efe61c1a3dc36189081ff ; affected 7e0b2b57f01d183e1c84114f1f2287737358d748 < f16fe84879a5280f05ebbcea593a189ba0f3e79a ; affected 7e0b2b57f01d183e1c84114f1f2287737358d748 < 070abdf1b04325b21a20a2a0c39a2208af107275 ; affected 7e0b2b57f01d183e1c84114f1f2287737358d748 < aa7cfa16f98f8ec3e6d47c34e1a8c1ae4b9b8b77 ; affected 7e0b2b57f01d183e1c84114f1f2287737358d748 < b42aca3660dc2627a29a38131597ca610dc451f9
Linux · Linuxaffected 4.19 ; unaffected 0 < 4.19 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.169 ≤ 6.1.* ; unaffected 6.6.135 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD