forked from mirrors/linux
5170836679
free_uid() and free_user_ns() are corecursive when CONFIG_USER_SCHED=n, but free_user_ns() is called from free_uid() by way of uid_hash_remove(), which requires uidhash_lock to be held. free_user_ns() then calls free_uid() to complete the destruction. Fix this by deferring the destruction of the user_namespace. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
57 lines
1.1 KiB
C
57 lines
1.1 KiB
C
#ifndef _LINUX_USER_NAMESPACE_H
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#define _LINUX_USER_NAMESPACE_H
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#include <linux/kref.h>
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#include <linux/nsproxy.h>
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#include <linux/sched.h>
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#include <linux/err.h>
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#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 8)
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#define UIDHASH_SZ (1 << UIDHASH_BITS)
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struct user_namespace {
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struct kref kref;
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struct hlist_head uidhash_table[UIDHASH_SZ];
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struct user_struct *creator;
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struct work_struct destroyer;
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};
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extern struct user_namespace init_user_ns;
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#ifdef CONFIG_USER_NS
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static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
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{
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if (ns)
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kref_get(&ns->kref);
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return ns;
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}
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extern int create_user_ns(struct cred *new);
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extern void free_user_ns(struct kref *kref);
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static inline void put_user_ns(struct user_namespace *ns)
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{
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if (ns)
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kref_put(&ns->kref, free_user_ns);
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}
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#else
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static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
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{
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return &init_user_ns;
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}
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static inline int create_user_ns(struct cred *new)
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{
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return -EINVAL;
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}
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static inline void put_user_ns(struct user_namespace *ns)
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{
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}
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#endif
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#endif /* _LINUX_USER_H */
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