nfsd: fix vm overcommit crash fix #2
commit 1b79cd04fab80be61dcd2732e2423aafde9a4c1c upstream.
The previous patch from Alan Cox ("nfsd: fix vm overcommit crash",
commit 731572d39fcd3498702eda4600db4c43d51e0b26) fixed the problem where
knfsd crashes on exported shmemfs objects and strict overcommit is set.
But the patch forgot supporting the case when CONFIG_SECURITY is
disabled.
This patch copies a part of his fix which is mainly for detecting a bug
earlier.
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Junjiro R. Okajima <hooanon05@yahoo.co.jp>
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>
diff --git a/include/linux/security.h b/include/linux/security.h
index afb426a..0601e71 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1823,19 +1823,23 @@
static inline int security_vm_enough_memory(long pages)
{
- return cap_vm_enough_memory(current->mm, pages);
-}
-
-static inline int security_vm_enough_memory_kern(long pages)
-{
+ WARN_ON(current->mm == NULL);
return cap_vm_enough_memory(current->mm, pages);
}
static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages)
{
+ WARN_ON(mm == NULL);
return cap_vm_enough_memory(mm, pages);
}
+static inline int security_vm_enough_memory_kern(long pages)
+{
+ /* If current->mm is a kernel thread then we will pass NULL,
+ for this specific case that is fine */
+ return cap_vm_enough_memory(current->mm, pages);
+}
+
static inline int security_bprm_alloc(struct linux_binprm *bprm)
{
return 0;
