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authorLi Zefan <lizf@cn.fujitsu.com>2012-01-09 14:27:42 +0800
committerLi Zefan <lizf@cn.fujitsu.com>2012-01-11 10:26:34 +0800
commita1ee5a45818acc7f9c13e560827cf3e8735ac919 (patch)
tree984505e8c99a6965453819651ff0ea91a4ca8d4b
parentdb804f23a72bada58f083dfad6a65d019ddb3bd4 (diff)
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>
-rw-r--r--fs/btrfs/free-space-cache.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 01840ef95a3..4e55af333e1 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]);
+ }
}
}