From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Tue, 5 Feb 2008 06:27:18 +0000 (-0800)
Subject: sys_remap_file_pages: fix ->vm_file accounting
X-Git-Tag: firefly_0821_release~23546
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8a459e44ad837018ea5c34a9efe8eb4ad27ded26;p=firefly-linux-kernel-4.4.55.git

sys_remap_file_pages: fix ->vm_file accounting

Fix ->vm_file accounting, mmap_region() may do do_munmap().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/fremap.c b/mm/fremap.c
index 14bd3bf7826e..69a37c2bdf81 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -190,10 +190,13 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
 		 */
 		if (mapping_cap_account_dirty(mapping)) {
 			unsigned long addr;
+			struct file *file = vma->vm_file;
 
 			flags &= MAP_NONBLOCK;
-			addr = mmap_region(vma->vm_file, start, size,
+			get_file(file);
+			addr = mmap_region(file, start, size,
 					flags, vma->vm_flags, pgoff, 1);
+			fput(file);
 			if (IS_ERR_VALUE(addr)) {
 				err = addr;
 			} else {