Jonathan Looney discovered that the TCP retransmission queue implementation in tcp_fragment in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. 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 f070ef2ac66716357066b683fb0baf55f8191a2e.
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https://security.netapp.com/advisory/ntap-20190625-0001/
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https://kc.mcafee.com/corporate/index?page=content&id=SB10287
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http://www.openwall.com/lists/oss-security/2019/10/29/3
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http://www.openwall.com/lists/oss-security/2019/07/06/4
http://www.openwall.com/lists/oss-security/2019/07/06/3
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