AZL-80645
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-80645.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/AZL-80645
- Upstream
- Published
- 2026-03-25T11:16:26Z
- Modified
- 2026-08-28T17:47:38Z
- Summary
- CVE-2026-23304 affecting package kernel for versions less than 6.6.130.1-1
- Details
-
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.
- References