x86/mce: Recover from poison found while copying from user space
[linux-2.6-microblaze.git] / fs / compat.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/compat.c
4  *
5  *  Kernel compatibililty routines for e.g. 32 bit syscall support
6  *  on 64 bit kernels.
7  *
8  *  Copyright (C) 2002       Stephen Rothwell, IBM Corporation
9  *  Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
10  *  Copyright (C) 1998       Eddie C. Dost  (ecd@skynet.be)
11  *  Copyright (C) 2001,2002  Andi Kleen, SuSE Labs 
12  *  Copyright (C) 2003       Pavel Machek (pavel@ucw.cz)
13  */
14
15 #include <linux/compat.h>
16 #include <linux/nfs4_mount.h>
17 #include <linux/syscalls.h>
18 #include <linux/slab.h>
19 #include <linux/uaccess.h>
20 #include "internal.h"
21
22 struct compat_nfs_string {
23         compat_uint_t len;
24         compat_uptr_t data;
25 };
26
27 static inline void compat_nfs_string(struct nfs_string *dst,
28                                      struct compat_nfs_string *src)
29 {
30         dst->data = compat_ptr(src->data);
31         dst->len = src->len;
32 }
33
34 struct compat_nfs4_mount_data_v1 {
35         compat_int_t version;
36         compat_int_t flags;
37         compat_int_t rsize;
38         compat_int_t wsize;
39         compat_int_t timeo;
40         compat_int_t retrans;
41         compat_int_t acregmin;
42         compat_int_t acregmax;
43         compat_int_t acdirmin;
44         compat_int_t acdirmax;
45         struct compat_nfs_string client_addr;
46         struct compat_nfs_string mnt_path;
47         struct compat_nfs_string hostname;
48         compat_uint_t host_addrlen;
49         compat_uptr_t host_addr;
50         compat_int_t proto;
51         compat_int_t auth_flavourlen;
52         compat_uptr_t auth_flavours;
53 };
54
55 static int do_nfs4_super_data_conv(void *raw_data)
56 {
57         int version = *(compat_uint_t *) raw_data;
58
59         if (version == 1) {
60                 struct compat_nfs4_mount_data_v1 *raw = raw_data;
61                 struct nfs4_mount_data *real = raw_data;
62
63                 /* copy the fields backwards */
64                 real->auth_flavours = compat_ptr(raw->auth_flavours);
65                 real->auth_flavourlen = raw->auth_flavourlen;
66                 real->proto = raw->proto;
67                 real->host_addr = compat_ptr(raw->host_addr);
68                 real->host_addrlen = raw->host_addrlen;
69                 compat_nfs_string(&real->hostname, &raw->hostname);
70                 compat_nfs_string(&real->mnt_path, &raw->mnt_path);
71                 compat_nfs_string(&real->client_addr, &raw->client_addr);
72                 real->acdirmax = raw->acdirmax;
73                 real->acdirmin = raw->acdirmin;
74                 real->acregmax = raw->acregmax;
75                 real->acregmin = raw->acregmin;
76                 real->retrans = raw->retrans;
77                 real->timeo = raw->timeo;
78                 real->wsize = raw->wsize;
79                 real->rsize = raw->rsize;
80                 real->flags = raw->flags;
81                 real->version = raw->version;
82         }
83
84         return 0;
85 }
86
87 #define NFS4_NAME       "nfs4"
88
89 COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
90                        const char __user *, dir_name,
91                        const char __user *, type, compat_ulong_t, flags,
92                        const void __user *, data)
93 {
94         char *kernel_type;
95         void *options;
96         char *kernel_dev;
97         int retval;
98
99         kernel_type = copy_mount_string(type);
100         retval = PTR_ERR(kernel_type);
101         if (IS_ERR(kernel_type))
102                 goto out;
103
104         kernel_dev = copy_mount_string(dev_name);
105         retval = PTR_ERR(kernel_dev);
106         if (IS_ERR(kernel_dev))
107                 goto out1;
108
109         options = copy_mount_options(data);
110         retval = PTR_ERR(options);
111         if (IS_ERR(options))
112                 goto out2;
113
114         if (kernel_type && options) {
115                 if (!strcmp(kernel_type, NFS4_NAME)) {
116                         retval = -EINVAL;
117                         if (do_nfs4_super_data_conv(options))
118                                 goto out3;
119                 }
120         }
121
122         retval = do_mount(kernel_dev, dir_name, kernel_type, flags, options);
123
124  out3:
125         kfree(options);
126  out2:
127         kfree(kernel_dev);
128  out1:
129         kfree(kernel_type);
130  out:
131         return retval;
132 }