{"id":"CVE-2026-23304","title":"ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()\n\nl3mdev_master_dev_rcu() can return NULL when the slave device is being\nun-slaved from a VRF. All other callers dea…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < d542e2ac7f9e288d49735be0775611547ca4e0ee","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < a73fe9f4ae84a239d5b2686f47a58c158aee2eb4","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 4a48fe59f29f673a3d042d679f26629a9c3e29d4","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 581800298313c9fd75e94985e6d37d21b7e35d34","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 3310fc11fc47387d1dd4759b0bc961643ea11c7f","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 0b5a7826020706057cc5a9d9009e667027f221ee","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < ae88c8256547b63980770a9ea7be73a15900d27e","Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a","Linux 4.14"],"published":"2026-03-25","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:45:32.838Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23304","references":[{"url":"https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee"},{"url":"https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4"},{"url":"https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4"},{"url":"https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34"},{"url":"https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f"},{"url":"https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee"},{"url":"https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e"},{"url":"https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a"}],"tags":["cve.org"],"epss":0.00129,"epssPercentile":0.02878,"ingestedAt":"2026-09-08T15:33:26.993Z","slug":"CVE-2026-23304","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()\n\nl3mdev_master_dev_rcu() can return NULL when the slave device is being\nun-slaved from a VRF. All other callers deal with this, but we lost\nthe fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu()\nwith commit 4832c30d5458 (\"net: ipv6: put host and anycast routes on\ndevice with address\").\n\n  KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]\n  RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418)\n  Call Trace:\n   ip6_pol_route (net/ipv6/route.c:2318)\n   fib6_rule_lookup (net/ipv6/fib6_rules.c:115)\n   ip6_route_output_flags (net/ipv6/route.c:2607)\n   vrf_process_v6_outbound (drivers/net/vrf.c:437)\n\nI was tempted to rework the un-slaving code to clear the flag first\nand insert synchronize_rcu() before we remove the upper. But looks like\nthe explicit fallback to loopback_dev is an established pattern.\nAnd I guess avoiding the synchronize_rcu() is nice, too.\n\n## Affected\n\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < d542e2ac7f9e288d49735be0775611547ca4e0ee`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < a73fe9f4ae84a239d5b2686f47a58c158aee2eb4`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 4a48fe59f29f673a3d042d679f26629a9c3e29d4`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 581800298313c9fd75e94985e6d37d21b7e35d34`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 3310fc11fc47387d1dd4759b0bc961643ea11c7f`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 0b5a7826020706057cc5a9d9009e667027f221ee`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < ae88c8256547b63980770a9ea7be73a15900d27e`\n- `Linux >= 4832c30d5458387ff2533ff66fbde26ad8bb5a2d < 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a`\n- `Linux 4.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}