Junos OS: EX2300 Series, EX2300-MP Series, EX3400 Series: A slow memory leak due to processing of specific IPv6 packets

Summary

An Improper Check for Unusual or Exceptional Conditions vulnerability in the processing of specific IPv6 packets on certain EX Series devices may lead to exhaustion of DMA memory causing a Denial of Service (DoS). Over time, exploitation of this vulnerability may cause traffic to stop being forwarded, or a crash of the fxpc process. An indication of the issue occurring may be observed through the following log messages: Sep 13 17:14:59 hostname : %PFE-3: fpc0 (buf alloc) failed allocating packet buffer Sep 13 17:14:59 hostname : %PFE-7: fpc0 brcm_pkt_buf_alloc:393 (buf alloc) failed allocating packet buffer When Packet DMA heap utilization reaches 99%, the system will become unstable. Packet DMA heap utilization can be monitored using the command: user@junos# request pfe execute target fpc0 timeout 30 command "show heap" ID Base Total(b) Free(b) Used(b) % Name -- ---------- ----------- ----------- ----------- --- ----------- 0 213301a8 536870488 387228840 149641648 27 Kernel 1 91800000 8388608 3735120 4653488 55 DMA 2 92000000 75497472 74452192 1045280 1 PKT DMA DESC 3 d330000 335544320 257091400 78452920 23 Bcm_sdk 4 96800000 184549376 2408 184546968 99 Packet DMA <<<< 5 903fffe0 20971504 20971504 0 0 Blob This issue affects: Juniper Networks Junos OS 18.4 versions prior to 18.4R2-S10, 18.4R3-S10 on EX2300 Series, EX2300-MP Series, EX3400 Series; 19.1 versions prior to 19.1R3-S7 on EX2300 Series, EX2300-MP Series, EX3400 Series; 19.2 versions prior to 19.2R1-S8, 19.2R3-S4 on EX2300 Series, EX2300-MP Series, EX3400 Series; 19.3 versions prior to 19.3R3-S5 on EX2300 Series, EX2300-MP Series, EX3400 Series; 19.4 versions prior to 19.4R3-S7 on EX2300 Series, EX2300-MP Series, EX3400 Series; 20.1 versions prior to 20.1R3-S3 on EX2300 Series, EX2300-MP Series, EX3400 Series; 20.2 versions prior to 20.2R3-S3 on EX2300 Series, EX2300-MP Series, EX3400 Series; 20.3 versions prior to 20.3R3-S2 on EX2300 Series, EX2300-MP Series, EX3400 Series; 20.4 versions prior to 20.4R3-S1 on EX2300 Series, EX2300-MP Series, EX3400 Series; 21.1 versions prior to 21.1R2-S2, 21.1R3 on EX2300 Series, EX2300-MP Series, EX3400 Series; 21.2 versions prior to 21.2R1-S2, 21.2R2 on EX2300 Series, EX2300-MP Series, EX3400 Series; 21.3 versions prior to 21.3R1-S1, 21.3R2 on EX2300 Series, EX2300-MP Series, EX3400 Series.