Уязвимость механизма TCP Selective Acknowledgement ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость механизма TCP Selective Acknowledgement ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость ядра операционной системы Linux, вызванная ошибками при обработке сегментов минимального размера, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость функции idr_remove_all() ядра Linux операционных систем Red Hat Enterprise Linux, позволяющая нарушителю повысить свои привилегии или вызвать отказ в обслуживании

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.

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.

Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. 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 commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.

A double-free can happen in idr_remove_all() in lib/idr.c in the Linux kernel 2.6 branch. An unprivileged local attacker can use this flaw for a privilege escalation or for a system crash and a denial of service (DoS).