ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() (Linux Linux)

CVE-2026-23304
MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.13 % · percentile 3 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too.

Weaknesses (CWE)

  • CWE-476 — NULL Pointer Dereference

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < d542e2ac7f9e288d49735be0775611547ca4e0ee ; affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 ; affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 4a48fe59f29f673a3d042d679f26629a9c3e29d4 ; affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 581800298313c9fd75e94985e6d37d21b7e35d34 ; affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 3310fc11fc47387d1dd4759b0bc961643ea11c7f ; affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 0b5a7826020706057cc5a9d9009e667027f221ee
Linux · Linuxaffected 4.14 ; unaffected 0 < 4.14 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.167 ≤ 6.1.* ; unaffected 6.6.130 ≤ 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