From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 30 Nov 2012 03:57:33 +0000 (-0500)
Subject: fix off-by-one in argument passed by iterate_fd() to callbacks
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a77cfcb429ed98845a4e4df72473b8f37acd890b;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

fix off-by-one in argument passed by iterate_fd() to callbacks

Noticed by Pavel Roskin; the thing in his patch I disagree with
was compensating for that shite in callbacks instead of fixing
it once in the iterator itself.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/file.c b/fs/file.c
index 7cb71b992603..eff23162485f 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -994,16 +994,18 @@ int iterate_fd(struct files_struct *files, unsigned n,
 		const void *p)
 {
 	struct fdtable *fdt;
-	struct file *file;
 	int res = 0;
 	if (!files)
 		return 0;
 	spin_lock(&files->file_lock);
-	fdt = files_fdtable(files);
-	while (!res && n < fdt->max_fds) {
-		file = rcu_dereference_check_fdtable(files, fdt->fd[n++]);
-		if (file)
-			res = f(p, file, n);
+	for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {
+		struct file *file;
+		file = rcu_dereference_check_fdtable(files, fdt->fd[n]);
+		if (!file)
+			continue;
+		res = f(p, file, n);
+		if (res)
+			break;
 	}
 	spin_unlock(&files->file_lock);
 	return res;