172 lines
3.8 KiB
C
172 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/stat.h>
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#include <linux/sysctl.h>
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#include "../fs/xfs/xfs_sysctl.h"
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#include <linux/sunrpc/debug.h>
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#include <linux/string.h>
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#include <linux/syscalls.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/fs.h>
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#include <linux/nsproxy.h>
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#include <linux/pid_namespace.h>
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#include <linux/file.h>
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#include <linux/ctype.h>
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#include <linux/netdevice.h>
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#include <linux/kernel.h>
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#include <linux/uuid.h>
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#include <linux/slab.h>
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#include <linux/compat.h>
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static ssize_t binary_sysctl(const int *name, int nlen,
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void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
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{
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return -ENOSYS;
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}
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static void deprecated_sysctl_warning(const int *name, int nlen)
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{
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int i;
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/*
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* CTL_KERN/KERN_VERSION is used by older glibc and cannot
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* ever go away.
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*/
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if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
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return;
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if (printk_ratelimit()) {
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printk(KERN_INFO
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"warning: process `%s' used the deprecated sysctl "
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"system call with ", current->comm);
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for (i = 0; i < nlen; i++)
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printk(KERN_CONT "%d.", name[i]);
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printk(KERN_CONT "\n");
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}
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return;
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}
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#define WARN_ONCE_HASH_BITS 8
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#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)
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static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);
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#define FNV32_OFFSET 2166136261U
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#define FNV32_PRIME 0x01000193
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/*
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* Print each legacy sysctl (approximately) only once.
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* To avoid making the tables non-const use a external
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* hash-table instead.
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* Worst case hash collision: 6, but very rarely.
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* NOTE! We don't use the SMP-safe bit tests. We simply
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* don't care enough.
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*/
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static void warn_on_bintable(const int *name, int nlen)
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{
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int i;
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u32 hash = FNV32_OFFSET;
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for (i = 0; i < nlen; i++)
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hash = (hash ^ name[i]) * FNV32_PRIME;
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hash %= WARN_ONCE_HASH_SIZE;
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if (__test_and_set_bit(hash, warn_once_bitmap))
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return;
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deprecated_sysctl_warning(name, nlen);
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}
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static ssize_t do_sysctl(int __user *args_name, int nlen,
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void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
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{
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int name[CTL_MAXNAME];
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int i;
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/* Check args->nlen. */
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if (nlen < 0 || nlen > CTL_MAXNAME)
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return -ENOTDIR;
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/* Read in the sysctl name for simplicity */
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for (i = 0; i < nlen; i++)
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if (get_user(name[i], args_name + i))
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return -EFAULT;
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warn_on_bintable(name, nlen);
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return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
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}
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SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
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{
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struct __sysctl_args tmp;
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size_t oldlen = 0;
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ssize_t result;
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if (copy_from_user(&tmp, args, sizeof(tmp)))
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return -EFAULT;
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if (tmp.oldval && !tmp.oldlenp)
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return -EFAULT;
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if (tmp.oldlenp && get_user(oldlen, tmp.oldlenp))
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return -EFAULT;
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result = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, oldlen,
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tmp.newval, tmp.newlen);
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if (result >= 0) {
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oldlen = result;
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result = 0;
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}
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if (tmp.oldlenp && put_user(oldlen, tmp.oldlenp))
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return -EFAULT;
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return result;
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}
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#ifdef CONFIG_COMPAT
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struct compat_sysctl_args {
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compat_uptr_t name;
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int nlen;
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compat_uptr_t oldval;
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compat_uptr_t oldlenp;
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compat_uptr_t newval;
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compat_size_t newlen;
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compat_ulong_t __unused[4];
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};
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COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args)
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{
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struct compat_sysctl_args tmp;
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compat_size_t __user *compat_oldlenp;
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size_t oldlen = 0;
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ssize_t result;
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if (copy_from_user(&tmp, args, sizeof(tmp)))
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return -EFAULT;
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if (tmp.oldval && !tmp.oldlenp)
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return -EFAULT;
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compat_oldlenp = compat_ptr(tmp.oldlenp);
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if (compat_oldlenp && get_user(oldlen, compat_oldlenp))
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return -EFAULT;
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result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
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compat_ptr(tmp.oldval), oldlen,
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compat_ptr(tmp.newval), tmp.newlen);
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if (result >= 0) {
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oldlen = result;
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result = 0;
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}
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if (compat_oldlenp && put_user(oldlen, compat_oldlenp))
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return -EFAULT;
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return result;
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}
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#endif /* CONFIG_COMPAT */
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