A use after free issue was found in the way Linux kernel's KVM hypervisor implements its device control API. While creating a device via kvmioctlcreatedevice(), device holds a reference to a VM object, latter this reference is transferred to caller's file descriptor table. If such file descriptor was to be closed, reference count to the VM object could become zero, potentially leading to use-after-free issue latter.

A user/process could use this flaw to crash the guest VM resulting in DoS issue OR potentially gain privileged access to a system.

Upstream patch: --------------- -> https://git.kernel.org/linus/cfa39381173d5f969daf43582c95ad679189cbc9

Reference: ---------- -> https://www.openwall.com/lists/oss-security/2019/02/18/2

A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcpcollapseofoqueue() and tcppruneofoqueue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses.

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).

In BIG-IP 14.0.0-14.0.0.2, 13.0.0-13.1.1.1, 12.1.0-12.1.3.6, 11.6.1-11.6.3.2, or 11.5.1-11.5.8, when processing fragmented ClientHello messages in a DTLS session TMM may corrupt memory eventually leading to a crash. Only systems offering DTLS connections via APM are impacted.

On F5 BIG-IP 13.1.x versions prior to 13.1.5, and all versions of 12.1.x and 11.6.x, when multiple route domains are configured, undisclosed requests to big3d can cause an increase in CPU resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5, 14.1.x versions prior to 14.1.4.6, and 13.1.x versions prior to 13.1.5, when a Real Time Streaming Protocol (RTSP) profile is configured on a virtual server, undisclosed traffic can cause an increase in Traffic Management Microkernel (TMM) resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, and 13.1.x versions prior to 13.1.5, on platforms with an ePVA and the pva.fwdaccel BigDB variable enabled, undisclosed requests to a virtual server with a FastL4 profile that has ePVA acceleration enabled can cause the Traffic Management Microkernel (TMM) process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

On all versions of 17.0.x, 16.1.x, 15.1.x, 14.1.x, 13.1.x, 12.1.x, and 11.6.x on F5 BIG-IP, an authenticated iControl REST user with at least guest role privileges can cause processing delays to iControl REST requests via undisclosed requests. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

On F5 BIG-IP LTM, Advanced WAF, ASM, or APM 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5, 14.1.x versions prior to 14.1.4.6, and all versions of 13.1.x, 12.1.x, and 11.6.x, when a virtual server is configured with HTTP, TCP on one side (client/server), and DTLS on the other (server/client), undisclosed requests can cause the TMM process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

When the F5 BIG-IP APM 13.0.0-13.1.1 or 12.1.0-12.1.3 renders certain pages (pages with a logon agent or a confirm box), the BIG-IP APM may disclose configuration information such as partition and agent names via URI parameters.

On F5 BIG-IP APM 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, 13.1.x versions prior to 13.1.5, and all versions of 12.1.x and 11.6.x, when APM is configured on a virtual server and the associated access profile is configured with APM AAA NTLM Auth, undisclosed requests can cause an increase in internal resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated