Don't copy bind mounts of /proc/<pid>/ns/mnt between namespaces. These files hold references to a mount namespace and copying them between namespaces could result in a reference counting loop. The current mnt_ns_loop test prevents loops on the assumption that mounts don't cross between namespaces. Unfortunately unsharing a mount namespace and shared substrees can both cause mounts to propogate between mount namespaces. Add two flags CL_COPY_UNBINDABLE and CL_COPY_MNT_NS_FILE are added to control this behavior, and CL_COPY_ALL is redefined as both of them. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
		
			
				
	
	
		
			51 lines
		
	
	
	
		
			1.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			51 lines
		
	
	
	
		
			1.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  linux/fs/pnode.h
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 *
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 * (C) Copyright IBM Corporation 2005.
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 *	Released under GPL v2.
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 *
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 */
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#ifndef _LINUX_PNODE_H
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#define _LINUX_PNODE_H
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#include <linux/list.h>
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#include "mount.h"
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#define IS_MNT_SHARED(m) ((m)->mnt.mnt_flags & MNT_SHARED)
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#define IS_MNT_SLAVE(m) ((m)->mnt_master)
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#define IS_MNT_NEW(m)  (!(m)->mnt_ns)
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#define CLEAR_MNT_SHARED(m) ((m)->mnt.mnt_flags &= ~MNT_SHARED)
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#define IS_MNT_UNBINDABLE(m) ((m)->mnt.mnt_flags & MNT_UNBINDABLE)
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#define CL_EXPIRE    		0x01
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#define CL_SLAVE     		0x02
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#define CL_COPY_UNBINDABLE	0x04
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#define CL_MAKE_SHARED 		0x08
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#define CL_PRIVATE 		0x10
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#define CL_SHARED_TO_SLAVE	0x20
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#define CL_UNPRIVILEGED		0x40
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#define CL_COPY_MNT_NS_FILE	0x80
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#define CL_COPY_ALL		(CL_COPY_UNBINDABLE | CL_COPY_MNT_NS_FILE)
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static inline void set_mnt_shared(struct mount *mnt)
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{
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	mnt->mnt.mnt_flags &= ~MNT_SHARED_MASK;
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	mnt->mnt.mnt_flags |= MNT_SHARED;
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}
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void change_mnt_propagation(struct mount *, int);
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int propagate_mnt(struct mount *, struct mountpoint *, struct mount *,
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		struct list_head *);
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int propagate_umount(struct list_head *);
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int propagate_mount_busy(struct mount *, int);
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void mnt_release_group_id(struct mount *);
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int get_dominating_id(struct mount *mnt, const struct path *root);
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unsigned int mnt_get_count(struct mount *mnt);
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void mnt_set_mountpoint(struct mount *, struct mountpoint *,
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			struct mount *);
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void umount_tree(struct mount *, int);
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struct mount *copy_tree(struct mount *, struct dentry *, int);
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bool is_path_reachable(struct mount *, struct dentry *,
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			 const struct path *root);
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#endif /* _LINUX_PNODE_H */
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