ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()
Summary
| CVE | CVE-2026-23304 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-25 11:16:26 UTC |
| Updated | 2026-04-18 09:16:18 UTC |
| 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. |
Risk And Classification
EPSS: 0.000320000 probability, percentile 0.090980000 (date 2026-04-18)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d d542e2ac7f9e288d49735be0775611547ca4e0ee git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d 4a48fe59f29f673a3d042d679f26629a9c3e29d4 git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d 581800298313c9fd75e94985e6d37d21b7e35d34 git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d 3310fc11fc47387d1dd4759b0bc961643ea11c7f git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d 0b5a7826020706057cc5a9d9009e667027f221ee git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d ae88c8256547b63980770a9ea7be73a15900d27e git | Not specified |
| CNA | Linux | Linux | affected 4832c30d5458387ff2533ff66fbde26ad8bb5a2d 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a git | Not specified |
| CNA | Linux | Linux | affected 4.14 | Not specified |
| CNA | Linux | Linux | unaffected 4.14 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.253 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.203 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.167 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.130 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.77 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.17 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.7 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.