Debian Security Advisory
DLA-246-2 linux-2.6 -- LTS security update
- Date Reported:
- 17 Jun 2015
- Affected Packages:
- Security database references:
- In the Debian bugtracking system: Bug 789037.
In Mitre's CVE dictionary: CVE-2011-5321, CVE-2012-6689, CVE-2014-3184, CVE-2014-8159, CVE-2014-9683, CVE-2014-9728, CVE-2014-9729, CVE-2014-9730, CVE-2014-9731, CVE-2015-1805, CVE-2015-2041, CVE-2015-2042, CVE-2015-2830, CVE-2015-2922, CVE-2015-3339, CVE-2015-4167.
- More information:
The linux-2.6 update issued as DLA-246-1 caused regressions. This update corrects the defective patches applied in that update causing these problems. For reference the original advisory text follows.
This update fixes the CVEs described below.
Jiri Slaby discovered that tty_driver_lookup_tty() may leak a reference to the tty driver. A local user could use this flaw to crash the system.
Pablo Neira Ayuso discovered that non-root user-space processes can send forged Netlink notifications to other processes. A local user could use this flaw for denial of service or privilege escalation.
Ben Hawkes discovered that various HID drivers may over-read the report descriptor buffer, possibly resulting in a crash if a HID with a crafted descriptor is plugged in.
It was found that the Linux kernel's InfiniBand/RDMA subsystem did not properly sanitize input parameters while registering memory regions from user space via the (u)verbs API. A local user with access to a /dev/infiniband/uverbsX device could use this flaw to crash the system or, potentially, escalate their privileges on the system.
Dmitry Chernenkov discovered that eCryptfs writes past the end of the allocated buffer during encrypted filename decoding, resulting in local denial of service.
- CVE-2014-9728 / CVE-2014-9729 / CVE-2014-9730 / CVE-2014-9731 / CVE-2015-4167
Carl Henrik Lunde discovered that the UDF implementation is missing several necessary length checks. A local user that can mount devices could use these various flaws to crash the system, to leak information from the kernel, or possibly for privilege escalation.
Red Hat discovered that the pipe iovec read and write implementations may iterate over the iovec twice but will modify the iovec such that the second iteration accesses the wrong memory. A local user could use this flaw to crash the system or possibly for privilege escalation. This may also result in data corruption and information leaks in pipes between non-malicious processes.
Sasha Levin discovered that the LLC subsystem exposed some variables as sysctls with the wrong type. On a 64-bit kernel, this possibly allows privilege escalation from a process with CAP_NET_ADMIN capability; it also results in a trivial information leak.
Sasha Levin discovered that the RDS subsystem exposed some variables as sysctls with the wrong type. On a 64-bit kernel, this results in a trivial information leak.
Andrew Lutomirski discovered that when a 64-bit task on an amd64 kernel makes a fork(2) or clone(2) system call using int $0x80, the 32-bit compatibility flag is set (correctly) but is not cleared on return. As a result, both seccomp and audit will misinterpret the following system call by the task(s), possibly leading to a violation of security policy.
Modio AB discovered that the IPv6 subsystem would process a router advertisement that specifies no route but only a hop limit, which would then be applied to the interface that received it. This can result in loss of IPv6 connectivity beyond the local network.
This may be mitigated by disabling processing of IPv6 router advertisements if they are not needed:
sysctl net.ipv6.conf.default.accept_ra=0 sysctl net.ipv6.conf.<interface>.accept_ra=0
It was found that the execve(2) system call can race with inode attribute changes made by chown(2). Although chown(2) clears the setuid/setgid bits of a file if it changes the respective owner ID, this race condition could result in execve(2) setting effective uid/gid to the new owner ID, a privilege escalation.
For the oldoldstable distribution (squeeze), these problems have been fixed in version 2.6.32-48squeeze12.
For the stable distribution (jessie), these problems were fixed in linux version 3.16.7-ckt11-1 or earlier, except for CVE-2015-4167 which will be fixed later.
We recommend that you upgrade your linux-2.6 packages.