Commit 9f98927f authored by ZhangPeng's avatar ZhangPeng Committed by Peng Zhang
Browse files

userswap: fix BUG_ON in userfaultfd_release() 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6CAIM



--------------------------------

In some features of userfaultfd, vma->vm_userfaultfd_ctx.ctx may be NULL
but VM_USWAP is not cleared. No longer check whether vma->vm_flags has
VM_USWAP. Just remove the flag.

Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent d8a73976

fs/userfaultfd.c

+3 −3
Original line number Diff line number Diff line
@@ -873,12 +873,12 @@ static int userfaultfd_release(struct inode *inode, struct file *file) 
	prev = NULL;

	for (vma = mm->mmap; vma; vma = vma->vm_next) {

		userfault_flags = VM_UFFD_MISSING | VM_UFFD_WP;

#ifdef CONFIG_USERSWAP

		uswap_release(&userfault_flags);

#endif

		cond_resched();

		BUG_ON(!!vma->vm_userfaultfd_ctx.ctx ^

		       !!(vma->vm_flags & userfault_flags));

#ifdef CONFIG_USERSWAP

		uswap_release(&userfault_flags);

#endif

		if (vma->vm_userfaultfd_ctx.ctx != ctx) {

			prev = vma;

			continue;