The kernel packages contain the Linux kernel, the core of any Linux operating system.
This update fixes the following security issues:
A buffer overflow flaw was found in the ecryptfs_uid_hash() function in the Linux kernel eCryptfs implementation. On systems that have the eCryptfs netlink transport (Red Hat Enterprise Linux 5 does) or where the "/dev/ecryptfs" file has world writable permissions (which it does not, by default, on Red Hat Enterprise Linux 5), a local, unprivileged user could use this flaw to cause a denial of service or possibly escalate their privileges. (CVE-2010-2492, Important)
A miscalculation of the size of the free space of the initial directory entry in a directory leaf block was found in the Linux kernel Global File System 2 (GFS2) implementation. A local, unprivileged user with write access to a GFS2-mounted file system could perform a rename operation on that file system to trigger a NULL pointer dereference, possibly resulting in a denial of service or privilege escalation. (CVE-2010-2798, Important)
A flaw was found in the Xen hypervisor implementation when running a system that has an Intel CPU without Extended Page Tables (EPT) support. While attempting to dump information about a crashing fully-virtualized guest, the flaw could cause the hypervisor to crash the host as well. A user with permissions to configure a fully-virtualized guest system could use this flaw to crash the host. (CVE-2010-2938, Moderate)
Information leak flaws were found in the Linux kernel's Traffic Control Unit implementation. A local attacker could use these flaws to cause the kernel to leak kernel memory to user-space, possibly leading to the disclosure of sensitive information. (CVE-2010-2942, Moderate)
A flaw was found in the Linux kernel's XFS file system implementation. The file handle lookup could return an invalid inode as valid. If an XFS file system was mounted via NFS (Network File System), a local attacker could access stale data or overwrite existing data that reused the inodes. (CVE-2010-2943, Moderate)
An integer overflow flaw was found in the extent range checking code in the Linux kernel's ext4 file system implementation. A local, unprivileged user with write access to an ext4-mounted file system could trigger this flaw by writing to a file at a very large file offset, resulting in a local denial of service. (CVE-2010-3015, Moderate)
An information leak flaw was found in the Linux kernel's USB implementation. Certain USB errors could result in an uninitialized kernel buffer being sent to user-space. An attacker with physical access to a target system could use this flaw to cause an information leak. (CVE-2010-1083, Low)
Red Hat would like to thank Andre Osterhues for reporting CVE-2010-2492; Grant Diffey of CenITex for reporting CVE-2010-2798; Toshiyuki Okajima for reporting CVE-2010-3015; and Marcus Meissner for reporting CVE-2010-1083.
This update also fixes several bugs. Documentation for these bug fixes will be available shortly from the Technical Notes document linked to in the References.
Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.