diff options
Diffstat (limited to 'main/linux-vanilla/fs-binfmt_elf-fix-memory-map-for-PIE-applications.patch')
| -rw-r--r-- | main/linux-vanilla/fs-binfmt_elf-fix-memory-map-for-PIE-applications.patch | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/main/linux-vanilla/fs-binfmt_elf-fix-memory-map-for-PIE-applications.patch b/main/linux-vanilla/fs-binfmt_elf-fix-memory-map-for-PIE-applications.patch new file mode 100644 index 0000000000..71e4dce991 --- /dev/null +++ b/main/linux-vanilla/fs-binfmt_elf-fix-memory-map-for-PIE-applications.patch @@ -0,0 +1,71 @@ +From 9bfe85ecddfd1a11376e7b4916f9b000aabd5da6 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi> +Date: Tue, 1 Oct 2013 13:46:04 +0300 +Subject: [PATCH] fs/binfmt_elf: fix memory map for PIE applications +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +arch/x86/include/asm/elf.h comment says: +" +ELF_ET_DYN_BASE is the location that an ET_DYN program is loaded +if exec'ed. Typical use of this is to invoke "./ld.so someprog" +to test out a new version of the loader. We need to make sure +that it is out of the way of the program that it will "exec", +and that there is sufficient room for the brk. +" + +In case we have main application linked as PIE, this will cause +problems as the main program itself will go the memory location +that allows very little heap. + +This fixes the loader to detect PIE application by checking if +elf_interpreter is requested, and loads them to beginning of the +address space instead of the specially crafted place for elf +interpreter. + +Signed-off-by: Timo Teräs <timo.teras@iki.fi> +--- + fs/binfmt_elf.c | 17 +++++++++++------ + 1 file changed, 11 insertions(+), 6 deletions(-) + +diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c +index 100edcc..1161e5d 100644 +--- a/fs/binfmt_elf.c ++++ b/fs/binfmt_elf.c +@@ -802,6 +802,10 @@ static int load_elf_binary(struct linux_binprm *bprm) + * 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. */ ++ if (elf_interpreter) ++ load_bias = 0x00400000UL; ++ else ++ load_bias = ELF_ET_DYN_BASE; + #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE + /* Memory randomization might have been switched off + * in runtime via sysctl or explicit setting of +@@ -810,13 +814,14 @@ static int load_elf_binary(struct linux_binprm *bprm) + * load_bias value in order to establish proper + * non-randomized mappings. + */ +- if (current->flags & PF_RANDOMIZE) +- load_bias = 0; +- else +- load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); +-#else +- load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); ++ if (current->flags & PF_RANDOMIZE) { ++ if (elf_interpreter) ++ load_bias += (get_random_int() & STACK_RND_MASK) << PAGE_SHIFT; ++ else ++ load_bias = 0; ++ } + #endif ++ load_bias = ELF_PAGESTART(vaddr + load_bias); + } + + error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, +-- +1.8.4 + + |