From: Daniel Rosenberg <drosen@google.com>
Date: Mon, 22 May 2017 20:23:56 +0000 (-0700)
Subject: ANDROID: sdcardfs: Check for NULL in revalidate
X-Git-Tag: release-20171130_firefly~4^2~100^2~100
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a9d65e521a0fed3668957719432d5c42383a3647;p=firefly-linux-kernel-4.4.55.git

ANDROID: sdcardfs: Check for NULL in revalidate

If the inode is in the process of being evicted,
the top value may be NULL.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 38502532
Change-Id: I0b9d04aab621e0398d44d1c5dc53293106aa5f89
---

diff --git a/fs/sdcardfs/dentry.c b/fs/sdcardfs/dentry.c
index 83ae9103a0f6..13da7e5245bd 100644
--- a/fs/sdcardfs/dentry.c
+++ b/fs/sdcardfs/dentry.c
@@ -109,14 +109,16 @@ static int sdcardfs_d_revalidate(struct dentry *dentry, unsigned int flags)
 		goto out;
 
 	/* If our top's inode is gone, we may be out of date */
-	inode = d_inode(dentry);
+	inode = igrab(d_inode(dentry));
 	if (inode) {
 		data = top_data_get(SDCARDFS_I(inode));
-		if (data->abandoned) {
+		if (!data || data->abandoned) {
 			d_drop(dentry);
 			err = 0;
 		}
-		data_put(data);
+		if (data)
+			data_put(data);
+		iput(inode);
 	}
 
 out: