Red Hat Security Advisory: kernel security update

Important

Linux kernel 2.6.17 and earlier, when running on IA64 or SPARC platforms, allows local users to cause a denial of service (crash) via a malformed ELF file that triggers memory maps that cross region boundaries.

The __block_prepare_write function in fs/buffer.c for Linux kernel 2.6.x before 2.6.13 does not properly clear buffers during certain error conditions, which allows local users to read portions of files that have been unlinked.

The mincore function in the Linux kernel before 2.4.33.6 does not properly lock access to user space, which has unspecified impact and attack vectors, possibly related to a deadlock.

The copy_from_user function in the uaccess code in Linux kernel 2.6 before 2.6.19-rc1, when running on s390, does not properly clear a kernel buffer, which allows local user space programs to read portions of kernel memory by "appending to a file from a bad address," which triggers a fault that prevents the unused memory from being cleared in the kernel buffer.

The seqfile handling (ip6fl_get_n function in ip6_flowlabel.c) in Linux kernel 2.6 up to 2.6.18-stable allows local users to cause a denial of service (hang or oops) via unspecified manipulations that trigger an infinite loop while searching for flowlabels.

Integer overflow in the get_fdb_entries function in net/bridge/br_ioctl.c in the Linux kernel before 2.6.18.4 allows local users to execute arbitrary code via a large maxnum value in an ioctl request.