[PATCH] RLIMIT_AS checking fix
Address bug #4508: there's potential for wraparound in the various places
where we perform RLIMIT_AS checking.
(I'm a bit worried about acct_stack_growth(). Are we sure that vma->vm_mm is
always equal to current->mm? If not, then we're comparing some other
process's total_vm with the calling process's rlimits).
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/mremap.c b/mm/mremap.c
index 0d1c1b9..0dd7ace 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -347,10 +347,10 @@
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
goto out;
}
- ret = -ENOMEM;
- if ((current->mm->total_vm << PAGE_SHIFT) + (new_len - old_len)
- > current->signal->rlim[RLIMIT_AS].rlim_cur)
+ if (!may_expand_vm(current->mm, (new_len - old_len) >> PAGE_SHIFT)) {
+ ret = -ENOMEM;
goto out;
+ }
if (vma->vm_flags & VM_ACCOUNT) {
charged = (new_len - old_len) >> PAGE_SHIFT;
