[PATCH 02/11] Btrfs: avoid possible NULL deref in io_ctl_drop_pages()
From: Li Zefan <hidden>
Date: 2012-01-11 05:52:23
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
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 <redacted> --- fs/btrfs/free-space-cache.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-)
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 @@ static void io_ctl_drop_pages(struct io_ctl *io_ctl) 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]); + } } }
--
1.7.3.1