Jonathan Looney discovered that the TCP_SKB_CB(skb)->tcp_gso_segs value was subject to an integer overflow in the Linux kernel when handling TCP Selective Acknowledgments (SACKs). A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commit 3b4929f65b0d8249f19a50245cd88ed1a2f78cff.
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https://www.synology.com/security/advisory/Synology_SA_19_28
https://www.oracle.com/security-alerts/cpuoct2020.html
https://www.oracle.com/security-alerts/cpujan2020.html
https://www.kb.cert.org/vuls/id/905115
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SACKPanic
https://support.f5.com/csp/article/K78234183
https://security.netapp.com/advisory/ntap-20190625-0001/
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2019-0006
https://kc.mcafee.com/corporate/index?page=content&id=SB10287
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44193
https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-001.md
https://cert-portal.siemens.com/productcert/pdf/ssa-462066.pdf
https://access.redhat.com/security/vulnerabilities/tcpsack
https://access.redhat.com/errata/RHSA-2019:1699
https://access.redhat.com/errata/RHSA-2019:1602
https://access.redhat.com/errata/RHSA-2019:1594
http://www.vmware.com/security/advisories/VMSA-2019-0010.html
http://www.openwall.com/lists/oss-security/2019/10/29/3
http://www.openwall.com/lists/oss-security/2019/10/24/1
http://www.openwall.com/lists/oss-security/2019/07/06/4
http://www.openwall.com/lists/oss-security/2019/07/06/3
http://www.openwall.com/lists/oss-security/2019/06/28/2
http://www.openwall.com/lists/oss-security/2019/06/20/3
http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20191225-01-kernel-en
http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-010.txt
http://packetstormsecurity.com/files/154951/Kernel-Live-Patch-Security-Notice-LSN-0058-1.html
http://packetstormsecurity.com/files/153346/Kernel-Live-Patch-Security-Notice-LSN-0052-1.html