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authorDavid Howells <dhowells@redhat.com>2009-09-23 15:57:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-24 07:21:02 -0700
commit8e8b63a68c7ec95ef23770813120f4f98c76e08b (patch)
tree82339b06388b2002557ec5fab7dcfa72c918b3c6 /fs/binfmt_elf_fdpic.c
parent0cf062d0ffa33d491e2695b0d298ccf9cbb58d3d (diff)
downloadlinux-linaro-stable-8e8b63a68c7ec95ef23770813120f4f98c76e08b.tar.gz
fdpic: ignore the loader's PT_GNU_STACK when calculating the stack size
Ignore the loader's PT_GNU_STACK when calculating the stack size, and only consider the executable's PT_GNU_STACK, assuming the executable has one. Currently the behaviour is to take the largest stack size and use that, but that means you can't reduce the stack size in the executable. The loader's stack size should probably only be used when executing the loader directly. WARNING: This patch is slightly dangerous - it may render a system inoperable if the loader's stack size is larger than that of important executables, and the system relies unknowingly on this increasing the size of the stack. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/binfmt_elf_fdpic.c')
-rw-r--r--fs/binfmt_elf_fdpic.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 76285471073e..38502c67987c 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -283,20 +283,23 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
}
stack_size = exec_params.stack_size;
- if (stack_size < interp_params.stack_size)
- stack_size = interp_params.stack_size;
-
if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
executable_stack = EXSTACK_ENABLE_X;
else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
executable_stack = EXSTACK_DISABLE_X;
- else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
- executable_stack = EXSTACK_ENABLE_X;
- else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
- executable_stack = EXSTACK_DISABLE_X;
else
executable_stack = EXSTACK_DEFAULT;
+ if (stack_size == 0) {
+ stack_size = interp_params.stack_size;
+ if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
+ executable_stack = EXSTACK_ENABLE_X;
+ else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
+ executable_stack = EXSTACK_DISABLE_X;
+ else
+ executable_stack = EXSTACK_DEFAULT;
+ }
+
retval = -ENOEXEC;
if (stack_size == 0)
goto error;