[PATCH] binfmt_elf: randomize PIE binaries (2nd try)
Randomizes -pie compiled binaries from 64k (0x10000) up to ELF_ET_DYN_BASE.
0 -> 64k is excluded to allow NULL ptr accesses to fail.
Signed-off-by: Marcus Meissner <meissner@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index cc72bb4..b2efbae 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -856,7 +856,13 @@
* default mmap base, as well as whatever program they
* might try to exec. This is because the brk will
* follow the loader, and is not movable. */
- load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
+ if (current->flags & PF_RANDOMIZE)
+ load_bias = randomize_range(0x10000,
+ ELF_ET_DYN_BASE,
+ 0);
+ else
+ load_bias = ELF_ET_DYN_BASE;
+ load_bias = ELF_PAGESTART(load_bias - vaddr);
}
error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,