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>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index f60aa3c..143d3f5 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3837,8 +3837,10 @@
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;
