diff options
| author | Amir Goldstein | 2017-07-18 21:07:43 +0300 |
|---|---|---|
| committer | Miklos Szeredi | 2017-07-20 11:08:21 +0200 |
| commit | 0e082555cec9510d276965fe391f709acb32c0f4 (patch) | |
| tree | 437e67241b032c2a0e3f009f9ae940839b077008 /fs/overlayfs | |
| parent | 61b674710cd9afa2a8b17bdd1ac80670c9b79f1d (diff) | |
ovl: check for bad and whiteout index on lookup
Index should always be of the same file type as origin, except for
the case of a whiteout index. A whiteout index should only exist
if all lower aliases have been unlinked, which means that finding
a lower origin on lookup whose index is a whiteout should be treated
as a lookup error.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/namei.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 229a88ff335c..8aef2b304b2d 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -513,6 +513,7 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry, goto out; } + inode = d_inode(index); if (d_is_negative(index)) { if (upper && d_inode(origin)->i_nlink > 1) { pr_warn_ratelimited("overlayfs: hard link with origin but no index (ino=%lu).\n", @@ -522,11 +523,22 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry, dput(index); index = NULL; - } else if (upper && d_inode(index) != d_inode(upper)) { - inode = d_inode(index); - pr_warn_ratelimited("overlayfs: wrong index found (index ino: %lu, upper ino: %lu).\n", - d_inode(index)->i_ino, - d_inode(upper)->i_ino); + } else if (upper && d_inode(upper) != inode) { + pr_warn_ratelimited("overlayfs: wrong index found (index=%pd2, ino=%lu, upper ino=%lu).\n", + index, inode->i_ino, d_inode(upper)->i_ino); + goto fail; + } else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) || + ((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) { + /* + * Index should always be of the same file type as origin + * except for the case of a whiteout index. A whiteout + * index should only exist if all lower aliases have been + * unlinked, which means that finding a lower origin on lookup + * whose index is a whiteout should be treated as an error. + */ + pr_warn_ratelimited("overlayfs: bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n", + index, d_inode(index)->i_mode & S_IFMT, + d_inode(origin)->i_mode & S_IFMT); goto fail; } |