[LU-12458] kernel update [RHEL7.6 3.10.0-957.21.3.el7]

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.13.0, Lustre 2.12.3
• Severity: 3
• Assignee: Jian Yu
• Reporter: Jian Yu

Description

Security Fix(es):

• An integer overflow flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS). (CVE-2019-11477)
• Kernel: tcp: excessive resource consumption while processing SACK blocks allows remote denial of service (CVE-2019-11478)
• Kernel: tcp: excessive resource consumption for TCP connections with low MSS allows remote denial of service (CVE-2019-11479)

https://access.redhat.com/errata/product/69/ver=/rhel---7/x86_64/RHSA-2019:1481

Issue Links

• is related to: LU-12608 kernel update [RHEL7.6 3.10.0-957.27.2.el7]
• is related to: LU-12384 kernel update [RHEL7.6 3.10.0-957.21.2.el7]