From 45f49bce99d008d6864a20324548f35936ba46fb Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Sun, 21 Nov 2010 22:27:44 -0500
Subject: [PATCH] Btrfs: avoid NULL pointer deref in try_release_extent_buffer
If we fail to find a pointer in the radix tree, don't try
to deref the NULL one we do have.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
fs/btrfs/extent_io.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index f60aa3c35c2334..143d3f541d6415 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3837,8 +3837,10 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
spin_lock(&tree->buffer_lock);
eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
- if (!eb)
- goto out;
+ if (!eb) {
+ spin_unlock(&tree->buffer_lock);
+ return ret;
+ }
if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
ret = 0;
--
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