| The Linux kernel before 2.6.31-rc7 does not properly prevent mmap
operations that target page zero and other low memory addresses, which
allows local users to gain privileges by exploiting NULL pointer
dereference vulnerabilities, related to (1) the default configuration
of the allow_unconfined_mmap_low boolean in SELinux on Red Hat
Enterprise Linux (RHEL) 5, (2) an error that causes
allow_unconfined_mmap_low to be ignored in the unconfined_t domain,
(3) lack of a requirement for the CAP_SYS_RAWIO capability for these
mmap operations, and (4) interaction between the mmap_min_addr
protection mechanism and certain application programs.
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