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VPR Score: 6.4
SynopsisThe remote CentOS host is missing one or more security updates.
DescriptionUpdated kernel packages that fix several security issues and several bugs are now available for Red Hat Enterprise Linux 4.
This update has been rated as having important security impact by the Red Hat Security Response Team.
The kernel packages contain the Linux kernel, the core of any Linux operating system.
This update fixes the following security issues :
* the ADDR_COMPAT_LAYOUT and MMAP_PAGE_ZERO flags were not cleared when a setuid or setgid program was executed. A local, unprivileged user could use this flaw to bypass the mmap_min_addr protection mechanism and perform a NULL pointer dereference attack, or bypass the Address Space Layout Randomization (ASLR) security feature.
* it was discovered that, when executing a new process, the clear_child_tid pointer in the Linux kernel is not cleared. If this pointer points to a writable portion of the memory of the new program, the kernel could corrupt four bytes of memory, possibly leading to a local denial of service or privilege escalation. (CVE-2009-2848, Important)
* Solar Designer reported a missing capability check in the z90crypt driver in the Linux kernel. This missing check could allow a local user with an effective user ID (euid) of 0 to bypass intended capability restrictions. (CVE-2009-1883, Moderate)
* a flaw was found in the way the do_sigaltstack() function in the Linux kernel copies the stack_t structure to user-space. On 64-bit machines, this flaw could lead to a four-byte information leak.
This update also fixes the following bugs :
* the gcc flag '-fno-delete-null-pointer-checks' was added to the kernel build options. This prevents gcc from optimizing out NULL pointer checks after the first use of a pointer. NULL pointer bugs are often exploited by attackers. Keeping these checks is a safety measure. (BZ#517964)
* the Emulex LPFC driver has been updated to version 126.96.36.199, which fixes a memory leak that caused memory allocation failures and system hangs. (BZ#513192)
* an error in the MPT Fusion driver makefile caused CSMI ioctls to not work with Serial Attached SCSI devices. (BZ#516184)
* this update adds the mmap_min_addr tunable and restriction checks to help prevent unprivileged users from creating new memory mappings below the minimum address. This can help prevent the exploitation of NULL pointer deference bugs. Note that mmap_min_addr is set to zero (disabled) by default for backwards compatibility. (BZ#517904)
* time-outs resulted in I/O errors being logged to '/var/log/messages' when running 'mt erase' on tape drives using certain LSI MegaRAID SAS adapters, preventing the command from completing. The megaraid_sas driver's timeout value is now set to the OS layer value. (BZ#517965)
* a locking issue caused the qla2xxx ioctl module to hang after encountering errors. This locking issue has been corrected. This ioctl module is used by the QLogic SAN management tools, such as SANsurfer and scli. (BZ#519428)
* when a RAID 1 array that uses the mptscsi driver and the LSI 1030 controller became degraded, the whole array was detected as being offline, which could cause kernel panics at boot or data loss.
* on 32-bit architectures, if a file was held open and frequently written for more than 25 days, it was possible that the kernel would stop flushing those writes to storage. (BZ#515255)
* a memory allocation bug in ib_mthca prevented the driver from loading if it was loaded with large values for the 'num_mpt=' and 'num_mtt=' options. (BZ#518707)
* with this update, get_random_int() is more random and no longer uses a common seed value, reducing the possibility of predicting the values returned. (BZ#519692)
* a bug in __ptrace_unlink() caused it to create deadlocked and unkillable processes. (BZ#519446)
* previously, multiple threads using the fcntl() F_SETLK command to synchronize file access caused a deadlock in posix_locks_deadlock().
This could cause a system hang. (BZ#519429)
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.
SolutionUpdate the affected kernel packages.