Synopsis: Important: kernel security and bug fix update
Issue date: 2009-09-15
CVE Names: CVE-2009-1883 CVE-2009-1895 CVE-2009-2847
CVE-2009-2848
CVE-2009-1883 kernel: missing capability check in z90crypt
CVE-2009-1895 kernel: personality: fix PER_CLEAR_ON_SETID
CVE-2009-2847 kernel: information leak in sigaltstack
CVE-2009-2848 kernel: execve: must clear current->clear_child_tid
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. (CVE-2009-1895, Important)
* 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. (CVE-2009-2847,
Moderate)
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 8.0.16.47, 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. (BZ#517295)
* 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)
The system must be rebooted for this update to take effect.
SL 4.x
SRPMS:
kernel-2.6.9-89.0.11.EL.src.rpm
i386:
x86_64:
-Connie Sieh
-Troy Dawson
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