Red Hat Security Advisory: kernel security, bug fix, and enhancement update

Important

A flaw was found in the way the get_dumpable() function return value was interpreted in the ptrace subsystem of the Linux kernel. When 'fs.suid_dumpable' was set to 2, a local, unprivileged local user could use this flaw to bypass intended ptrace restrictions and obtain potentially sensitive information.

A flaw was found in the way the ipc_rcu_putref() function in the Linux kernel's IPC implementation handled reference counter decrementing. A local, unprivileged user could use this flaw to trigger an Out of Memory (OOM) condition and, potentially, crash the system.

Xen 3.0.3 through 4.1.x (possibly 4.1.6.1), 4.2.x (possibly 4.2.3), and 4.3.x (possibly 4.3.1) does not properly prevent access to hypercalls, which allows local guest users to gain privileges via a crafted application running in ring 1 or 2.

Buffer overflow in the qeth_snmp_command function in drivers/s390/net/qeth_core_main.c in the Linux kernel through 3.12.1 allows local users to cause a denial of service or possibly have unspecified other impact via an SNMP ioctl call with a length value that is incompatible with the command-buffer size.

CWE-119 - Improper Restriction of Operations within the Bounds of a Memory Buffer

The aac_compat_ioctl function in drivers/scsi/aacraid/linit.c in the Linux kernel before 3.11.8 does not require the CAP_SYS_RAWIO capability, which allows local users to bypass intended access restrictions via a crafted ioctl call.

The microcode on AMD 16h 00h through 0Fh processors does not properly handle the interaction between locked instructions and write-combined memory types, which allows local users to cause a denial of service (system hang) via a crafted application, aka the errata 793 issue.

CWE-1220 - Insufficient Granularity of Access Control

The Linux kernel before 3.12.4 updates certain length values before ensuring that associated data structures have been initialized, which allows local users to obtain sensitive information from kernel stack memory via a (1) recvfrom, (2) recvmmsg, or (3) recvmsg system call, related to net/ipv4/ping.c, net/ipv4/raw.c, net/ipv4/udp.c, net/ipv6/raw.c, and net/ipv6/udp.c.