| Description: | Linux distributions that have not patched their long-term kernels with
https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86
(committed on April 14, 2015). This kernel vulnerability was fixed in
April 2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86
(backported to Linux 3.10.77 in May 2015), but it was not recognized
as a security threat. With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
enabled, and a normal top-down address allocation strategy,
load_elf_binary() will attempt to map a PIE binary into an address
range immediately below mm->mmap_base. Unfortunately, load_elf_
binary() does not take account of the need to allocate sufficient
space for the entire binary which means that, while the first PT_LOAD
segment is mapped below mm->mmap_base, the subsequent PT_LOAD
segment(s) end up being mapped above mm->mmap_base into the are that
is supposed to be the "gap" between the stack and the binary.
|
