From 1b79cd04fab80be61dcd2732e2423aafde9a4c1c Mon Sep 17 00:00:00 2001 From: "Junjiro R. Okajima" Date: Tue, 2 Dec 2008 10:31:46 -0800 Subject: [PATCH] nfsd: fix vm overcommit crash fix #2 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 Signed-off-by: Alan Cox Signed-off-by: Junjiro R. Okajima Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/security.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index c13f1cec9abb..e3d4ecda2673 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1818,17 +1818,21 @@ static inline int security_settime(struct timespec *ts, struct timezone *tz) static inline int security_vm_enough_memory(long pages) { + WARN_ON(current->mm == NULL); return cap_vm_enough_memory(current->mm, pages); } -static inline int security_vm_enough_memory_kern(long pages) +static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { - return cap_vm_enough_memory(current->mm, pages); + WARN_ON(mm == NULL); + return cap_vm_enough_memory(mm, pages); } -static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) +static inline int security_vm_enough_memory_kern(long pages) { - return cap_vm_enough_memory(mm, 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) -- 2.20.1