220 lines
6.3 KiB
C
220 lines
6.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* This is <linux/capability.h>
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*
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* Andrew G. Morgan <morgan@kernel.org>
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* Alexander Kjeldaas <astor@guardian.no>
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* with help from Aleph1, Roland Buresund and Andrew Main.
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*
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* See here for the libcap library ("POSIX draft" compliance):
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*
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* ftp://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/
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*/
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#ifndef _LINUX_CAPABILITY_H
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#define _LINUX_CAPABILITY_H
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#include <uapi/linux/capability.h>
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#include <linux/uidgid.h>
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#include <linux/bits.h>
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#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
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extern int file_caps_enabled;
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typedef struct { u64 val; } kernel_cap_t;
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/* same as vfs_ns_cap_data but in cpu endian and always filled completely */
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struct cpu_vfs_cap_data {
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__u32 magic_etc;
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kuid_t rootid;
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kernel_cap_t permitted;
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kernel_cap_t inheritable;
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};
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#define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct))
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#define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t))
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struct file;
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struct inode;
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struct dentry;
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struct task_struct;
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struct user_namespace;
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struct mnt_idmap;
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/*
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* CAP_FS_MASK and CAP_NFSD_MASKS:
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*
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* The fs mask is all the privileges that fsuid==0 historically meant.
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* At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.
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*
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* It has never meant setting security.* and trusted.* xattrs.
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*
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* We could also define fsmask as follows:
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* 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions
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* 2. The security.* and trusted.* xattrs are fs-related MAC permissions
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*/
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# define CAP_FS_MASK (BIT_ULL(CAP_CHOWN) \
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| BIT_ULL(CAP_MKNOD) \
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| BIT_ULL(CAP_DAC_OVERRIDE) \
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| BIT_ULL(CAP_DAC_READ_SEARCH) \
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| BIT_ULL(CAP_FOWNER) \
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| BIT_ULL(CAP_FSETID) \
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| BIT_ULL(CAP_MAC_OVERRIDE))
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#define CAP_VALID_MASK (BIT_ULL(CAP_LAST_CAP+1)-1)
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# define CAP_EMPTY_SET ((kernel_cap_t) { 0 })
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# define CAP_FULL_SET ((kernel_cap_t) { CAP_VALID_MASK })
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# define CAP_FS_SET ((kernel_cap_t) { CAP_FS_MASK | BIT_ULL(CAP_LINUX_IMMUTABLE) })
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# define CAP_NFSD_SET ((kernel_cap_t) { CAP_FS_MASK | BIT_ULL(CAP_SYS_RESOURCE) })
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# define cap_clear(c) do { (c).val = 0; } while (0)
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#define cap_raise(c, flag) ((c).val |= BIT_ULL(flag))
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#define cap_lower(c, flag) ((c).val &= ~BIT_ULL(flag))
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#define cap_raised(c, flag) (((c).val & BIT_ULL(flag)) != 0)
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static inline kernel_cap_t cap_combine(const kernel_cap_t a,
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const kernel_cap_t b)
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{
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return (kernel_cap_t) { a.val | b.val };
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}
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static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
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const kernel_cap_t b)
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{
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return (kernel_cap_t) { a.val & b.val };
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}
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static inline kernel_cap_t cap_drop(const kernel_cap_t a,
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const kernel_cap_t drop)
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{
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return (kernel_cap_t) { a.val &~ drop.val };
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}
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static inline bool cap_isclear(const kernel_cap_t a)
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{
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return !a.val;
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}
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static inline bool cap_isidentical(const kernel_cap_t a, const kernel_cap_t b)
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{
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return a.val == b.val;
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}
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/*
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* Check if "a" is a subset of "set".
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* return true if ALL of the capabilities in "a" are also in "set"
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* cap_issubset(0101, 1111) will return true
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* return false if ANY of the capabilities in "a" are not in "set"
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* cap_issubset(1111, 0101) will return false
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*/
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static inline bool cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
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{
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return !(a.val & ~set.val);
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}
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/* Used to decide between falling back on the old suser() or fsuser(). */
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static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
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{
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return cap_drop(a, CAP_FS_SET);
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}
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static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
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const kernel_cap_t permitted)
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{
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return cap_combine(a, cap_intersect(permitted, CAP_FS_SET));
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}
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static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
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{
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return cap_drop(a, CAP_NFSD_SET);
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}
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static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
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const kernel_cap_t permitted)
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{
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return cap_combine(a, cap_intersect(permitted, CAP_NFSD_SET));
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}
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#ifdef CONFIG_MULTIUSER
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extern bool has_capability(struct task_struct *t, int cap);
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extern bool has_ns_capability(struct task_struct *t,
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struct user_namespace *ns, int cap);
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extern bool has_capability_noaudit(struct task_struct *t, int cap);
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extern bool has_ns_capability_noaudit(struct task_struct *t,
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struct user_namespace *ns, int cap);
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extern bool capable(int cap);
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extern bool ns_capable(struct user_namespace *ns, int cap);
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extern bool ns_capable_noaudit(struct user_namespace *ns, int cap);
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extern bool ns_capable_setid(struct user_namespace *ns, int cap);
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#else
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static inline bool has_capability(struct task_struct *t, int cap)
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{
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return true;
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}
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static inline bool has_ns_capability(struct task_struct *t,
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struct user_namespace *ns, int cap)
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{
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return true;
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}
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static inline bool has_capability_noaudit(struct task_struct *t, int cap)
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{
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return true;
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}
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static inline bool has_ns_capability_noaudit(struct task_struct *t,
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struct user_namespace *ns, int cap)
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{
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return true;
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}
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static inline bool capable(int cap)
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{
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return true;
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}
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static inline bool ns_capable(struct user_namespace *ns, int cap)
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{
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return true;
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}
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static inline bool ns_capable_noaudit(struct user_namespace *ns, int cap)
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{
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return true;
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}
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static inline bool ns_capable_setid(struct user_namespace *ns, int cap)
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{
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return true;
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}
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#endif /* CONFIG_MULTIUSER */
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bool privileged_wrt_inode_uidgid(struct user_namespace *ns,
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struct mnt_idmap *idmap,
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const struct inode *inode);
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bool capable_wrt_inode_uidgid(struct mnt_idmap *idmap,
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const struct inode *inode, int cap);
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extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);
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extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns);
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static inline bool perfmon_capable(void)
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{
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return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN);
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}
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static inline bool bpf_capable(void)
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{
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return capable(CAP_BPF) || capable(CAP_SYS_ADMIN);
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}
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static inline bool checkpoint_restore_ns_capable(struct user_namespace *ns)
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{
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return ns_capable(ns, CAP_CHECKPOINT_RESTORE) ||
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ns_capable(ns, CAP_SYS_ADMIN);
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}
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/* audit system wants to get cap info from files as well */
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int get_vfs_caps_from_disk(struct mnt_idmap *idmap,
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const struct dentry *dentry,
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struct cpu_vfs_cap_data *cpu_caps);
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int cap_convert_nscap(struct mnt_idmap *idmap, struct dentry *dentry,
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const void **ivalue, size_t size);
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#endif /* !_LINUX_CAPABILITY_H */
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