From 4b1862e4fc6967bf326107ac0d5695157f32c25d Mon Sep 17 00:00:00 2001
From: Tadeusz Struk <tadeusz.struk@linaro.org>
Date: Mon, 3 Jan 2022 12:50:26 -0800
Subject: [PATCH] ANDROID: incremental-fs: fix GPF in
 pending_reads_dispatch_ioctl

It is possible that fget returns NULL. This needs to be handled
correctly in ioctl_permit_fill.

Bug: 212821226

Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Change-Id: Iec8be21982afeab6794b78ab1a542671c52acea2
---
 fs/incfs/pseudo_files.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/incfs/pseudo_files.c b/fs/incfs/pseudo_files.c
index 1a664f1478d5..1b9bf000f598 100644
--- a/fs/incfs/pseudo_files.c
+++ b/fs/incfs/pseudo_files.c
@@ -147,8 +147,12 @@ static long ioctl_permit_fill(struct file *f, void __user *arg)
 		return -EFAULT;
 
 	file = fget(permit_fill.file_descriptor);
-	if (IS_ERR(file))
+	if (IS_ERR_OR_NULL(file)) {
+		if (!file)
+			return -ENOENT;
+
 		return PTR_ERR(file);
+	}
 
 	if (file->f_op != &incfs_file_ops) {
 		error = -EPERM;