Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "This contains a fix for a potential crash/corruption issue and another
  where the suid/sgid bits weren't cleared on write"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: verify upper dentry in ovl_remove_and_whiteout()
  ovl: Copy up underlying inode's ->i_mode to overlay inode
  ovl: handle ATTR_KILL*
This commit is contained in:
Linus Torvalds 2016-07-23 14:25:02 +09:00
commit 88083e9845
3 changed files with 29 additions and 32 deletions

View file

@ -505,6 +505,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
struct dentry *upper;
struct dentry *opaquedir = NULL;
int err;
int flags = 0;
if (WARN_ON(!workdir))
return -EROFS;
@ -534,46 +535,39 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
if (err)
goto out_dput;
upper = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(upper);
if (IS_ERR(upper))
goto out_unlock;
err = -ESTALE;
if ((opaquedir && upper != opaquedir) ||
(!opaquedir && ovl_dentry_upper(dentry) &&
upper != ovl_dentry_upper(dentry))) {
goto out_dput_upper;
}
whiteout = ovl_whiteout(workdir, dentry);
err = PTR_ERR(whiteout);
if (IS_ERR(whiteout))
goto out_unlock;
goto out_dput_upper;
upper = ovl_dentry_upper(dentry);
if (!upper) {
upper = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(upper);
if (IS_ERR(upper))
goto kill_whiteout;
if (d_is_dir(upper))
flags = RENAME_EXCHANGE;
err = ovl_do_rename(wdir, whiteout, udir, upper, 0);
dput(upper);
if (err)
goto kill_whiteout;
} else {
int flags = 0;
err = ovl_do_rename(wdir, whiteout, udir, upper, flags);
if (err)
goto kill_whiteout;
if (flags)
ovl_cleanup(wdir, upper);
if (opaquedir)
upper = opaquedir;
err = -ESTALE;
if (upper->d_parent != upperdir)
goto kill_whiteout;
if (is_dir)
flags |= RENAME_EXCHANGE;
err = ovl_do_rename(wdir, whiteout, udir, upper, flags);
if (err)
goto kill_whiteout;
if (is_dir)
ovl_cleanup(wdir, upper);
}
ovl_dentry_version_inc(dentry->d_parent);
out_d_drop:
d_drop(dentry);
dput(whiteout);
out_dput_upper:
dput(upper);
out_unlock:
unlock_rename(workdir, upperdir);
out_dput:

View file

@ -80,6 +80,9 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
goto out_drop_write;
}
if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
attr->ia_valid &= ~ATTR_MODE;
inode_lock(upperdentry->d_inode);
err = notify_change(upperdentry, attr, NULL);
if (!err)
@ -410,12 +413,11 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
if (!inode)
return NULL;
mode &= S_IFMT;
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_flags |= S_NOATIME | S_NOCMTIME;
mode &= S_IFMT;
switch (mode) {
case S_IFDIR:
inode->i_private = oe;

View file

@ -187,6 +187,7 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to)
{
to->i_uid = from->i_uid;
to->i_gid = from->i_gid;
to->i_mode = from->i_mode;
}
/* dir.c */