{
const struct inode *inode;
const struct inode *parent;
+ kuid_t puid;
if (!sysctl_protected_symlinks)
return 0;
return 0;
/* Allowed if parent directory and link owner match. */
- if (uid_eq(parent->i_uid, inode->i_uid))
+ puid = parent->i_uid;
+ if (uid_valid(puid) && uid_eq(puid, inode->i_uid))
return 0;
if (nd->flags & LOOKUP_RCU)
* - sysctl_protected_hardlinks enabled
* - fsuid does not match inode
* - hardlink source is unsafe (see safe_hardlink_source() above)
- * - not CAP_FOWNER
+ * - not CAP_FOWNER in a namespace with the inode owner uid mapped
*
* Returns 0 if successful, -ve on error.
*/
static int may_linkat(struct path *link)
{
- const struct cred *cred;
struct inode *inode;
if (!sysctl_protected_hardlinks)
return 0;
- cred = current_cred();
inode = link->dentry->d_inode;
/* Source inode owner (or CAP_FOWNER) can hardlink all they like,
* otherwise, it must be a safe source.
*/
- if (uid_eq(cred->fsuid, inode->i_uid) || safe_hardlink_source(inode) ||
- capable(CAP_FOWNER))
+ if (inode_owner_or_capable(inode) || safe_hardlink_source(inode))
return 0;
audit_log_link_denied("linkat", link);
return 0;
if (!follow)
return 0;
+ /* make sure that d_is_symlink above matches inode */
+ if (nd->flags & LOOKUP_RCU) {
+ if (read_seqcount_retry(&link->dentry->d_seq, seq))
+ return -ECHILD;
+ }
return pick_link(nd, link, inode, seq);
}
if (err < 0)
return err;
- inode = d_backing_inode(path.dentry);
seq = 0; /* we are already out of RCU mode */
err = -ENOENT;
if (d_is_negative(path.dentry))
goto out_path_put;
+ inode = d_backing_inode(path.dentry);
}
if (flags & WALK_PUT)
if (err) {
const char *s = get_link(nd);
- if (unlikely(IS_ERR(s)))
+ if (IS_ERR(s))
return PTR_ERR(s);
err = 0;
if (unlikely(!s)) {
nd->last_type = LAST_ROOT; /* if there are only slashes... */
nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
nd->depth = 0;
- nd->total_link_count = 0;
if (flags & LOOKUP_ROOT) {
struct dentry *root = nd->root.dentry;
struct inode *inode = root->d_inode;
dentry = lookup_real(dir, dentry, nd->flags);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
-
- if (create_error) {
- int open_flag = op->open_flag;
-
- error = create_error;
- if ((open_flag & O_EXCL)) {
- if (!dentry->d_inode)
- goto out;
- } else if (!dentry->d_inode) {
- goto out;
- } else if ((open_flag & O_TRUNC) &&
- d_is_reg(dentry)) {
- goto out;
- }
- /* will fail later, go on to get the right error */
- }
+ }
+ if (create_error && !dentry->d_inode) {
+ error = create_error;
+ goto out;
}
looked_up:
path->dentry = dentry;
return error;
BUG_ON(nd->flags & LOOKUP_RCU);
- inode = d_backing_inode(path.dentry);
seq = 0; /* out of RCU mode, so the value doesn't matter */
if (unlikely(d_is_negative(path.dentry))) {
path_to_nameidata(&path, nd);
return -ENOENT;
}
+ inode = d_backing_inode(path.dentry);
finish_lookup:
if (nd->depth)
put_link(nd);
if (unlikely(error))
return error;
- if (unlikely(d_is_symlink(path.dentry)) && !(open_flag & O_PATH)) {
- path_to_nameidata(&path, nd);
- return -ELOOP;
- }
-
if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
path_to_nameidata(&path, nd);
} else {
return error;
}
audit_inode(nd->name, nd->path.dentry, 0);
+ if (unlikely(d_is_symlink(nd->path.dentry)) && !(open_flag & O_PATH)) {
+ error = -ELOOP;
+ goto out;
+ }
error = -EISDIR;
if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
goto out;
goto exit_fput;
}
out:
+ if (unlikely(error > 0)) {
+ WARN_ON(1);
+ error = -EINVAL;
+ }
if (got_write)
mnt_drop_write(nd->path.mnt);
path_put(&save_parent);
return ERR_PTR(-ELOOP);
filename = getname_kernel(name);
- if (unlikely(IS_ERR(filename)))
+ if (IS_ERR(filename))
return ERR_CAST(filename);
set_nameidata(&nd, -1, filename);
bool new_is_dir = false;
unsigned max_links = new_dir->i_sb->s_max_links;
- if (source == target)
+ /*
+ * Check source == target.
+ * On overlayfs need to look at underlying inodes.
+ */
+ if (vfs_select_inode(old_dentry, 0) == vfs_select_inode(new_dentry, 0))
return 0;
error = may_delete(old_dir, old_dentry, is_dir);
int page_symlink(struct inode *inode, const char *symname, int len)
{
return __page_symlink(inode, symname, len,
- !(mapping_gfp_mask(inode->i_mapping) & __GFP_FS));
+ !mapping_gfp_constraint(inode->i_mapping, __GFP_FS));
}
EXPORT_SYMBOL(page_symlink);