From: David Howells <dhowells@redhat.com>
Date: Thu, 16 Mar 2017 16:27:48 +0000 (+0000)
Subject: afs: Fix page leak in afs_write_begin()
X-Git-Tag: v3.18.89~37
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b1718fdda0f2d47634c0e8e96b0a77cfc34d4424;p=thirdparty%2Fkernel%2Fstable.git

afs: Fix page leak in afs_write_begin()


[ Upstream commit 6d06b0d25209c80e99c1e89700f1e09694a3766b ]

afs_write_begin() leaks a ref and a lock on a page if afs_fill_page()
fails.  Fix the leak by unlocking and releasing the page in the error path.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 24f11d2deeb28..9f816624e2120 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -149,12 +149,12 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
 		kfree(candidate);
 		return -ENOMEM;
 	}
-	*pagep = page;
-	/* page won't leak in error case: it eventually gets cleaned off LRU */
 
 	if (!PageUptodate(page) && len != PAGE_CACHE_SIZE) {
 		ret = afs_fill_page(vnode, key, index << PAGE_CACHE_SHIFT, page);
 		if (ret < 0) {
+			unlock_page(page);
+			put_page(page);
 			kfree(candidate);
 			_leave(" = %d [prep]", ret);
 			return ret;
@@ -162,6 +162,9 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
 		SetPageUptodate(page);
 	}
 
+	/* page won't leak in error case: it eventually gets cleaned off LRU */
+	*pagep = page;
+
 try_again:
 	spin_lock(&vnode->writeback_lock);