[thirdparty/linux.git] / kernel / sysctl_binary.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/stat.h>
#include <linux/sysctl.h>
#include "../fs/xfs/xfs_sysctl.h"
#include <linux/sunrpc/debug.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/fs.h>
#include <linux/nsproxy.h>
#include <linux/pid_namespace.h>
#include <linux/file.h>
#include <linux/ctype.h>
#include <linux/netdevice.h>
#include <linux/kernel.h>
#include <linux/uuid.h>
#include <linux/slab.h>
#include <linux/compat.h>

static ssize_t binary_sysctl(const int *name, int nlen,
	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
{
	return -ENOSYS;
}

static void deprecated_sysctl_warning(const int *name, int nlen)
{
	int i;

	/*
	 * CTL_KERN/KERN_VERSION is used by older glibc and cannot
	 * ever go away.
	 */
	if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
		return;

	if (printk_ratelimit()) {
		printk(KERN_INFO
			"warning: process `%s' used the deprecated sysctl "
			"system call with ", current->comm);
		for (i = 0; i < nlen; i++)
			printk(KERN_CONT "%d.", name[i]);
		printk(KERN_CONT "\n");
	}
	return;
}

#define WARN_ONCE_HASH_BITS 8
#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)

static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);

#define FNV32_OFFSET 2166136261U
#define FNV32_PRIME 0x01000193

/*
 * Print each legacy sysctl (approximately) only once.
 * To avoid making the tables non-const use a external
 * hash-table instead.
 * Worst case hash collision: 6, but very rarely.
 * NOTE! We don't use the SMP-safe bit tests. We simply
 * don't care enough.
 */
static void warn_on_bintable(const int *name, int nlen)
{
	int i;
	u32 hash = FNV32_OFFSET;

	for (i = 0; i < nlen; i++)
		hash = (hash ^ name[i]) * FNV32_PRIME;
	hash %= WARN_ONCE_HASH_SIZE;
	if (__test_and_set_bit(hash, warn_once_bitmap))
		return;
	deprecated_sysctl_warning(name, nlen);
}

static ssize_t do_sysctl(int __user *args_name, int nlen,
	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
{
	int name[CTL_MAXNAME];
	int i;

	/* Check args->nlen. */
	if (nlen < 0 || nlen > CTL_MAXNAME)
		return -ENOTDIR;
	/* Read in the sysctl name for simplicity */
	for (i = 0; i < nlen; i++)
		if (get_user(name[i], args_name + i))
			return -EFAULT;

	warn_on_bintable(name, nlen);

	return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
}

SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
{
	struct __sysctl_args tmp;
	size_t oldlen = 0;
	ssize_t result;

	if (copy_from_user(&tmp, args, sizeof(tmp)))
		return -EFAULT;

	if (tmp.oldval && !tmp.oldlenp)
		return -EFAULT;

	if (tmp.oldlenp && get_user(oldlen, tmp.oldlenp))
		return -EFAULT;

	result = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, oldlen,
			   tmp.newval, tmp.newlen);

	if (result >= 0) {
		oldlen = result;
		result = 0;
	}

	if (tmp.oldlenp && put_user(oldlen, tmp.oldlenp))
		return -EFAULT;

	return result;
}


#ifdef CONFIG_COMPAT

struct compat_sysctl_args {
	compat_uptr_t	name;
	int		nlen;
	compat_uptr_t	oldval;
	compat_uptr_t	oldlenp;
	compat_uptr_t	newval;
	compat_size_t	newlen;
	compat_ulong_t	__unused[4];
};

COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args)
{
	struct compat_sysctl_args tmp;
	compat_size_t __user *compat_oldlenp;
	size_t oldlen = 0;
	ssize_t result;

	if (copy_from_user(&tmp, args, sizeof(tmp)))
		return -EFAULT;

	if (tmp.oldval && !tmp.oldlenp)
		return -EFAULT;

	compat_oldlenp = compat_ptr(tmp.oldlenp);
	if (compat_oldlenp && get_user(oldlen, compat_oldlenp))
		return -EFAULT;

	result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
			   compat_ptr(tmp.oldval), oldlen,
			   compat_ptr(tmp.newval), tmp.newlen);

	if (result >= 0) {
		oldlen = result;
		result = 0;
	}

	if (compat_oldlenp && put_user(oldlen, compat_oldlenp))
		return -EFAULT;

	return result;
}

#endif /* CONFIG_COMPAT */
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
afa588b2 EB	2	#include <linux/stat.h>
afa588b2 EB	3	#include <linux/sysctl.h>
c59d87c4	4	#include "../fs/xfs/xfs_sysctl.h"
afa588b2 EB	5	#include <linux/sunrpc/debug.h>
afa588b2 EB	6	#include <linux/string.h>
afa588b2 EB	7	#include <linux/syscalls.h>
	8	#include <linux/namei.h>
	9	#include <linux/mount.h>
	10	#include <linux/fs.h>
	11	#include <linux/nsproxy.h>
	12	#include <linux/pid_namespace.h>
	13	#include <linux/file.h>
	14	#include <linux/ctype.h>
63395b65	15	#include <linux/netdevice.h>
69e4469a	16	#include <linux/kernel.h>
ede9c277	17	#include <linux/uuid.h>
5a0e3ad6	18	#include <linux/slab.h>
c5ddd202	19	#include <linux/compat.h>
afa588b2	20
26a7034b EB	21	static ssize_t binary_sysctl(const int *name, int nlen,
26a7034b EB	22	void __user oldval, size_t oldlen, void __user newval, size_t newlen)
afa588b2	23	{
2830b683	24	return -ENOSYS;
afa588b2 EB	25	}
afa588b2 EB	26
2830b683	27	static void deprecated_sysctl_warning(const int *name, int nlen)
afa588b2	28	{
afa588b2 EB	29	int i;
afa588b2 EB	30
61cf6931 AK	31	/*
	32	* CTL_KERN/KERN_VERSION is used by older glibc and cannot
	33	* ever go away.
	34	*/
9380fa60	35	if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
61cf6931 AK	36	return;
61cf6931 AK	37
2fb10732	38	if (printk_ratelimit()) {
afa588b2 EB	39	printk(KERN_INFO
	40	"warning: process `%s' used the deprecated sysctl "
	41	"system call with ", current->comm);
2830b683	42	for (i = 0; i < nlen; i++)
7560ef39 TH	43	printk(KERN_CONT "%d.", name[i]);
7560ef39 TH	44	printk(KERN_CONT "\n");
afa588b2	45	}
2830b683 EB	46	return;
	47	}
	48
4440095c AK	49	#define WARN_ONCE_HASH_BITS 8
	50	#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)
	51
	52	static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);
	53
	54	#define FNV32_OFFSET 2166136261U
	55	#define FNV32_PRIME 0x01000193
	56
	57	/*
	58	* Print each legacy sysctl (approximately) only once.
	59	* To avoid making the tables non-const use a external
	60	* hash-table instead.
	61	* Worst case hash collision: 6, but very rarely.
	62	* NOTE! We don't use the SMP-safe bit tests. We simply
	63	* don't care enough.
	64	*/
	65	static void warn_on_bintable(const int *name, int nlen)
	66	{
	67	int i;
	68	u32 hash = FNV32_OFFSET;
	69
	70	for (i = 0; i < nlen; i++)
	71	hash = (hash ^ name[i]) * FNV32_PRIME;
	72	hash %= WARN_ONCE_HASH_SIZE;
	73	if (__test_and_set_bit(hash, warn_once_bitmap))
	74	return;
	75	deprecated_sysctl_warning(name, nlen);
	76	}
	77
26a7034b EB	78	static ssize_t do_sysctl(int __user *args_name, int nlen,
26a7034b EB	79	void __user oldval, size_t oldlen, void __user newval, size_t newlen)
2830b683 EB	80	{
2830b683 EB	81	int name[CTL_MAXNAME];
2830b683 EB	82	int i;
2830b683 EB	83
26a7034b EB	84	/* Check args->nlen. */
26a7034b EB	85	if (nlen < 0 \|\| nlen > CTL_MAXNAME)
2830b683	86	return -ENOTDIR;
2830b683 EB	87	/* Read in the sysctl name for simplicity */
	88	for (i = 0; i < nlen; i++)
	89	if (get_user(name[i], args_name + i))
	90	return -EFAULT;
	91
4440095c	92	warn_on_bintable(name, nlen);
2830b683	93
26a7034b	94	return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
2830b683 EB	95	}
2830b683 EB	96
2830b683 EB	97	SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
	98	{
	99	struct __sysctl_args tmp;
26a7034b EB	100	size_t oldlen = 0;
26a7034b EB	101	ssize_t result;
2830b683 EB	102
	103	if (copy_from_user(&tmp, args, sizeof(tmp)))
	104	return -EFAULT;
	105
26a7034b EB	106	if (tmp.oldval && !tmp.oldlenp)
	107	return -EFAULT;
	108
	109	if (tmp.oldlenp && get_user(oldlen, tmp.oldlenp))
	110	return -EFAULT;
	111
	112	result = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, oldlen,
	113	tmp.newval, tmp.newlen);
	114
	115	if (result >= 0) {
	116	oldlen = result;
	117	result = 0;
	118	}
2830b683	119
26a7034b EB	120	if (tmp.oldlenp && put_user(oldlen, tmp.oldlenp))
	121	return -EFAULT;
	122
	123	return result;
afa588b2	124	}
da3f6f9b	125
26a7034b	126
da3f6f9b	127	#ifdef CONFIG_COMPAT
da3f6f9b EB	128
	129	struct compat_sysctl_args {
	130	compat_uptr_t name;
	131	int nlen;
	132	compat_uptr_t oldval;
	133	compat_uptr_t oldlenp;
	134	compat_uptr_t newval;
	135	compat_size_t newlen;
	136	compat_ulong_t __unused[4];
	137	};
	138
c5ddd202	139	COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args)
da3f6f9b EB	140	{
	141	struct compat_sysctl_args tmp;
	142	compat_size_t __user *compat_oldlenp;
da3f6f9b EB	143	size_t oldlen = 0;
	144	ssize_t result;
	145
	146	if (copy_from_user(&tmp, args, sizeof(tmp)))
	147	return -EFAULT;
	148
26a7034b EB	149	if (tmp.oldval && !tmp.oldlenp)
26a7034b EB	150	return -EFAULT;
da3f6f9b	151
26a7034b EB	152	compat_oldlenp = compat_ptr(tmp.oldlenp);
	153	if (compat_oldlenp && get_user(oldlen, compat_oldlenp))
	154	return -EFAULT;
da3f6f9b	155
da3f6f9b	156	result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
26a7034b	157	compat_ptr(tmp.oldval), oldlen,
da3f6f9b	158	compat_ptr(tmp.newval), tmp.newlen);
da3f6f9b	159
26a7034b EB	160	if (result >= 0) {
	161	oldlen = result;
	162	result = 0;
da3f6f9b EB	163	}
da3f6f9b EB	164
26a7034b EB	165	if (compat_oldlenp && put_user(oldlen, compat_oldlenp))
	166	return -EFAULT;
	167
da3f6f9b EB	168	return result;
	169	}
	170
	171	#endif /* CONFIG_COMPAT */