ext2: unbugger ext2_empty_dir()
authorAl Viro <viro@zeniv.linux.org.uk>
Sat, 26 Nov 2022 03:17:17 +0000 (03:17 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 7 Jan 2023 10:11:40 +0000 (11:11 +0100)
commit 27e714c007e4ad01837bf0fac5c11913a38d7695 upstream.

In 27cfa258951a "ext2: fix fs corruption when trying to remove
a non-empty directory with IO error" a funny thing has happened:

-               page = ext2_get_page(inode, i, dir_has_error, &page_addr);
+               page = ext2_get_page(inode, i, 0, &page_addr);

 -               if (IS_ERR(page)) {
 -                       dir_has_error = 1;
 -                       continue;
 -               }
 +               if (IS_ERR(page))
 +                       goto not_empty;

And at not_empty: we hit ext2_put_page(page, page_addr), which does
put_page(page).  Which, unless I'm very mistaken, should oops
immediately when given ERR_PTR(-E...) as page.

OK, shit happens, insufficiently tested patches included.  But when
commit in question describes the fault-injection test that exercised
that particular failure exit...

Ow.

CC: stable@vger.kernel.org
Fixes: 27cfa258951a ("ext2: fix fs corruption when trying to remove a non-empty directory with IO error")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ext2/dir.c

index 8f59775..5202edd 100644 (file)
@@ -679,7 +679,7 @@ int ext2_empty_dir (struct inode * inode)
                page = ext2_get_page(inode, i, 0, &page_addr);
 
                if (IS_ERR(page))
-                       goto not_empty;
+                       return 0;
 
                kaddr = page_addr;
                de = (ext2_dirent *)kaddr;