Product Affected

This issue affects Junos OS 21.2, 21.3, 21.4.
High
7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Problem

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.


This issue was seen during production usage.

This issue has been assigned CVE-2022-22209.
 

Solution

The following software releases have been updated to resolve this specific issue: 21.2R3, 21.3R2-S1, 21.3R3, 21.4R1-S2, 21.4R2, 22.1R1, and all subsequent releases.
 

Note: Only those releases listed in the PROBLEM section above are affected. This fix has also been proactively committed into other releases that are not vulnerable to this issue.
 

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).
 

This issue is being tracked as 1642172.

Workaround

There are no known workarounds for this issue.
 

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History

2022-07-13: Initial publication

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