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authorHugh Dickins <hugh@veritas.com>2008-07-10 21:19:20 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-10 13:25:43 -0700
commit96a8e13ed44e380fc2bb6c711d74d5ba698c00b2 (patch)
tree62eb5b26a3cfe678f82f9d5c131b08114950f551
parentf8804d39462dc019ae9d1a6e4d45512e9dfec2bf (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.c2
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