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authorJiri Kosina <jkosina@suse.cz>2011-11-02 13:37:41 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-11 09:43:41 -0800
commit47c5d5e0bb289d3f25b2521304eb22b8e23d2b65 (patch)
tree50c77d3846989c6c0ff02f4d3d4c5dd8e39e0e16 /fs
parent1e565a292a31ca798604b25b780e1878b4bb00cb (diff)
downloadlinux-linaro-precise-47c5d5e0bb289d3f25b2521304eb22b8e23d2b65.tar.gz
binfmt_elf: fix PIE execution with randomization disabled
commit a3defbe5c337dbc6da911f8cc49ae3cc3b49b453 upstream. The case of address space randomization being disabled in runtime through randomize_va_space sysctl is not treated properly in load_elf_binary(), resulting in SIGKILL coming at exec() time for certain PIE-linked binaries in case the randomization has been disabled at runtime prior to calling exec(). Handle the randomize_va_space == 0 case the same way as if we were not supporting .text randomization at all. Based on original patch by H.J. Lu and Josh Boyer. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Russell King <rmk@arm.linux.org.uk> Cc: H.J. Lu <hongjiu.lu@intel.com> Cc: <stable@kernel.org> Tested-by: Josh Boyer <jwboyer@redhat.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/binfmt_elf.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index dd0fdfc56d3..21ac5ee4b43 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -795,7 +795,16 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
* might try to exec. This is because the brk will
* follow the loader, and is not movable. */
#if defined(CONFIG_X86) || defined(CONFIG_ARM)
- load_bias = 0;
+ /* Memory randomization might have been switched off
+ * in runtime via sysctl.
+ * 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);
#endif