mirror of
https://gitlab.alpinelinux.org/alpine/aports.git
synced 2026-01-09 10:42:12 +01:00
69 lines
2.6 KiB
Diff
69 lines
2.6 KiB
Diff
From 21f973f87f480e3d24f1cb6c22b71253d25a3ea1 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 3.10-grsec] 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/*/include/asm/elf.h comments say:
|
|
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 can cause
|
|
problems as the main program itself is being loaded to this
|
|
alternate address. And this allows limited heap size. While
|
|
this is inevitable when exec'ing the interpreter directly,
|
|
we should do better for PIE applications.
|
|
|
|
This fixes the loader to detect PIE application by checking if
|
|
elf_interpreter is requested. This images are loaded to beginning
|
|
of the address space instead of the specially crafted place for elf
|
|
interpreter. This allows full heap address space for PIE applications
|
|
and fixes random "out of memory" errors.
|
|
|
|
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
|
|
---
|
|
fs/binfmt_elf.c | 14 ++++++--------
|
|
1 file changed, 6 insertions(+), 8 deletions(-)
|
|
|
|
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
|
|
index 6f036ed..06419af 100644
|
|
--- a/fs/binfmt_elf.c
|
|
+++ b/fs/binfmt_elf.c
|
|
@@ -1217,21 +1217,19 @@ 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
|
|
* personality flags.
|
|
- * If that is the case, retain the original non-zero
|
|
- * 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);
|
|
+ load_bias = (get_random_int() & STACK_RND_MASK) << PAGE_SHIFT;
|
|
#endif
|
|
+ load_bias = ELF_PAGESTART(load_bias - vaddr);
|
|
|
|
#ifdef CONFIG_PAX_RANDMMAP
|
|
/* PaX: randomize base address at the default exe base if requested */
|
|
--
|
|
1.8.4
|
|
|
|
|