CVE-2016-8645 Amazon Linux Security Advisory for kernel: ALAS-2016-772

CVE-2016-8645 kernel: a BUG() statement can be hit in net/ipv4/tcp_input.c
It was discovered that the Linux kernel since 3.6-rc1 with net.ipv4.tcp_fastopen; set to 1 can hit BUG() statement in tcp_collapse() function after making a number of certain syscalls leading to a possible system crash.

CVE-2016-8655 kernel: Race condition in packet_set_ring leads to use after free
A race condition issue leading to a use-after-free flaw was found in the way the raw packet sockets implementation in the Linux kernel networking subsystem handled synchronization while creating the TPACKET_V3 ring buffer. A local user able to open a raw packet socket (requires the CAP_NET_RAW capability) could use this flaw to elevate their privileges on the system.

CVE-2016-9083 kernel: State machine confusion bug in vfio driver leading to memory corruption
A flaw was discovered in the Linux kernel's implementation of VFIO. An attacker issuing an ioctl can create a situation where memory is corrupted and modify memory outside of the expected area. This may overwrite kernel memory and subvert kernel execution.

CVE-2016-9084 kernel: Integer overflow when using kzalloc in vfio driver
The use of a kzalloc with an integer multiplication allowed an integer overflow condition to be reached in vfio_pci_intrs.c. This combined with CVE-2016-9083 may allow an attacker to craft an attack and use unallocated memory, potentially crashing the machine.

Allows unauthorized disclosure of information; allows unauthorized modification; allows disruption of service.

Please refer to Amazon advisory ALAS-2016-772 for affected packages and patching details, or update with your package manager.

Patch:
Following are links for downloading patches to fix the vulnerabilities:

ALAS-2016-772: Amazon Linux (kernel (4.4.35-33.55.amzn1) on noarch)

ALAS-2016-772: Amazon Linux (kernel (4.4.35-33.55.amzn1) on x86_64)

ALAS-2016-772: Amazon Linux (kernel (4.4.35-33.55.amzn1) on src)

ALAS-2016-772: Amazon Linux (kernel (4.4.35-33.55.amzn1) on i686)