diff options
| author | Hugh Dickins <hugh@veritas.com> | 2008-07-10 21:19:20 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-10 13:25:43 -0700 |
| commit | 96a8e13ed44e380fc2bb6c711d74d5ba698c00b2 (patch) | |
| tree | 62eb5b26a3cfe678f82f9d5c131b08114950f551 | |
| parent | f8804d39462dc019ae9d1a6e4d45512e9dfec2bf (diff) | |
exec: fix stack excutability without PT_GNU_STACK
Kernel Bugzilla #11063 points out that on some architectures (e.g. x86_32)
exec'ing an ELF without a PT_GNU_STACK program header should default to an
executable stack; but this got broken by the unlimited argv feature because
stack vma is now created before the right personality has been established:
so breaking old binaries using nested function trampolines.
Therefore re-evaluate VM_STACK_FLAGS in setup_arg_pages, where stack
vm_flags used to be set, before the mprotect_fixup. Checking through
our existing VM_flags, none would have changed since insert_vm_struct:
so this seems safer than finding a way through the personality labyrinth.
Reported-by: pageexec@freemail.hu
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/exec.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c index da94a6f05df..fd9234379e8 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -610,7 +610,7 @@ int setup_arg_pages(struct linux_binprm *bprm, bprm->exec -= stack_shift; down_write(&mm->mmap_sem); - vm_flags = vma->vm_flags; + vm_flags = VM_STACK_FLAGS; /* * Adjust stack execute permissions; explicitly enable for |