Btrfs: avoid possible NULL deref in io_ctl_drop_pages()
If we run into some failure path in io_ctl_prepare_pages(),
io_ctl->pages[] array may have some NULL pointers.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 01840ef..4e55af3 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -319,9 +319,11 @@
io_ctl_unmap_page(io_ctl);
for (i = 0; i < io_ctl->num_pages; i++) {
- ClearPageChecked(io_ctl->pages[i]);
- unlock_page(io_ctl->pages[i]);
- page_cache_release(io_ctl->pages[i]);
+ if (io_ctl->pages[i]) {
+ ClearPageChecked(io_ctl->pages[i]);
+ unlock_page(io_ctl->pages[i]);
+ page_cache_release(io_ctl->pages[i]);
+ }
}
}