Commits
Konstantin Khorenko authored 686acf0945d
rh/net/tcp: fixes for CVE-2019-11477/CVE-2019-11478/CVE-2019-11479 This is a combined patch for 3 security issues: * 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) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Patches are taken from RHEL kernel: 2019-06-14 Jan Stancek <jstancek@redhat.com> [3.10.0-957.21.3.el7] - [net] tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() (Florian Westphal) [1719914 1719915] {CVE-2019-11479} - [net] tcp: add tcp_min_snd_mss sysctl (Florian Westphal) [1719914 1719915] {CVE-2019-11479} - [net] tcp: tcp_fragment() should apply sane memory limits (Florian Westphal) [1719849 1719850] {CVE-2019-11478} - [net] tcp: limit payload size of sacked skbs (Florian Westphal) [1719594 1719595] {CVE-2019-11477} - [net] tcp: pass previous skb to tcp_shifted_skb() (Florian Westphal) [1719594 1719595] {CVE-2019-11477} https://access.redhat.com/errata/RHSA-2019:1481 https://jira.sw.ru/browse/PSBM-95672 https://jira.sw.ru/browse/PSBM-95576 https://jira.sw.ru/browse/PSBM-95578 https://jira.sw.ru/browse/PSBM-95579 Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>