A Missing Release of Memory after Effective Lifetime vulnerability in the kernel of Juniper Networks Junos OS allows an unauthenticated network based attacker to cause a Denial of Service (DoS). On all Junos platforms, the Kernel Routing Table (KRT) queue can get stuck due to a memory leak triggered by interface flaps or route churn leading to RIB and PFEs getting out of sync. The memory leak causes RTNEXTHOP/route and next-hop memory pressure issue and the KRT queue will eventually get stuck with the error- ENOMEM – Cannot allocate memory. The out-of-sync state between RIB and FIB can be seen with the show route and show route forwarding-table command. This issue will lead to failures for adding new routes. The KRT queue status can be checked using the CLI command show krt queue: user@host > show krt state High-priority add queue: 1 queued ADD nhtype Router index 0 (31212) error ENOMEM – Cannot allocate memory kqp 0x8ad5e40 The following messages will be observed in /var/log/messages, which indicate high memory for routes/nexthops: host rpd[16279]: RPD_RT_HWM_NOTICE: New RIB highwatermark for routes: 266 [2022-03-04 05:06:07] host rpd[16279]: RPD_KRT_Q_RETRIES: nexthop ADD: Cannot allocate memory host rpd[16279]: RPD_KRT_Q_RETRIES: nexthop ADD: Cannot allocate memory host kernel: rts_veto_net_delayed_unref_limit: Route/nexthop memory is severe pressure. User Application to perform recovery actions. O p 8 err 12, rtsm_id 0:-1, msg type 10, veto simulation: 0. host kernel: rts_veto_net_delayed_unref_limit: Memory usage of M_RTNEXTHOP type = (806321208) Max size possible for M_RTNEXTHOP type = (689432176) Current delayed unref = (0), Max delayed unref on this platform = (120000) Current delayed weight unref = (0) Max delayed weight unref on this platform = (400000) curproc = rpd. This issue affects: Juniper Networks Junos OS 21.2 versions prior to 21.2R3; 21.3 versions prior to 21.3R2-S1, 21.3R3; 21.4 versions prior to 21.4R1-S2, 21.4R2; This issue does not affect Juniper Networks Junos OS versions prior to 21.2R1.
The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Junos | Juniper | 21.2 (including) | 21.2 (including) |
| Junos | Juniper | 21.2-r1 (including) | 21.2-r1 (including) |
| Junos | Juniper | 21.2-r1-s1 (including) | 21.2-r1-s1 (including) |
| Junos | Juniper | 21.2-r1-s2 (including) | 21.2-r1-s2 (including) |
| Junos | Juniper | 21.2-r2 (including) | 21.2-r2 (including) |
| Junos | Juniper | 21.2-r2-s1 (including) | 21.2-r2-s1 (including) |
| Junos | Juniper | 21.2-r2-s2 (including) | 21.2-r2-s2 (including) |
| Junos | Juniper | 21.3 (including) | 21.3 (including) |
| Junos | Juniper | 21.3-r1 (including) | 21.3-r1 (including) |
| Junos | Juniper | 21.3-r1-s1 (including) | 21.3-r1-s1 (including) |
| Junos | Juniper | 21.3-r1-s2 (including) | 21.3-r1-s2 (including) |
| Junos | Juniper | 21.3-r2 (including) | 21.3-r2 (including) |
| Junos | Juniper | 21.4 (including) | 21.4 (including) |
| Junos | Juniper | 21.4-r1 (including) | 21.4-r1 (including) |
| Junos | Juniper | 21.4-r1-s1 (including) | 21.4-r1-s1 (including) |