Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | File: fs/xattr.c |
| 3 | |
| 4 | Extended attribute handling. |
| 5 | |
| 6 | Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org> |
| 7 | Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com> |
| 8 | Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 9 | */ |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/file.h> |
| 13 | #include <linux/xattr.h> |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 14 | #include <linux/mount.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/namei.h> |
| 16 | #include <linux/security.h> |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 17 | #include <linux/evm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/syscalls.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 19 | #include <linux/export.h> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 20 | #include <linux/fsnotify.h> |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 21 | #include <linux/audit.h> |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 22 | #include <linux/vmalloc.h> |
Eric W. Biederman | 2f6f065 | 2012-02-07 18:52:57 -0800 | [diff] [blame] | 23 | #include <linux/posix_acl_xattr.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 25 | #include <asm/uaccess.h> |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 26 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 27 | /* |
| 28 | * Check permissions for extended attribute access. This is a bit complicated |
| 29 | * because different namespaces have very different rules. |
| 30 | */ |
| 31 | static int |
| 32 | xattr_permission(struct inode *inode, const char *name, int mask) |
| 33 | { |
| 34 | /* |
| 35 | * We can never set or remove an extended attribute on a read-only |
| 36 | * filesystem or on an immutable / append-only inode. |
| 37 | */ |
| 38 | if (mask & MAY_WRITE) { |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 39 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) |
| 40 | return -EPERM; |
| 41 | } |
| 42 | |
| 43 | /* |
| 44 | * No restriction for security.* and system.* from the VFS. Decision |
| 45 | * on these is left to the underlying filesystem / security module. |
| 46 | */ |
| 47 | if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) || |
| 48 | !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 49 | return 0; |
| 50 | |
| 51 | /* |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 52 | * The trusted.* namespace can only be accessed by privileged users. |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 53 | */ |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 54 | if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) { |
| 55 | if (!capable(CAP_SYS_ADMIN)) |
| 56 | return (mask & MAY_WRITE) ? -EPERM : -ENODATA; |
| 57 | return 0; |
| 58 | } |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 59 | |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 60 | /* |
| 61 | * In the user.* namespace, only regular files and directories can have |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 62 | * extended attributes. For sticky directories, only the owner and |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 63 | * privileged users can write attributes. |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 64 | */ |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 65 | if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) { |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 66 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 67 | return (mask & MAY_WRITE) ? -EPERM : -ENODATA; |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 68 | if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) && |
Serge E. Hallyn | 2e14967 | 2011-03-23 16:43:26 -0700 | [diff] [blame] | 69 | (mask & MAY_WRITE) && !inode_owner_or_capable(inode)) |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 70 | return -EPERM; |
| 71 | } |
| 72 | |
SamarV-121 | b575711 | 2020-09-21 05:47:44 +0000 | [diff] [blame] | 73 | return inode_permission2(ERR_PTR(-EOPNOTSUPP), inode, mask); |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 74 | } |
| 75 | |
David P. Quigley | b1ab7e4 | 2009-09-03 14:25:56 -0400 | [diff] [blame] | 76 | /** |
| 77 | * __vfs_setxattr_noperm - perform setxattr operation without performing |
| 78 | * permission checks. |
| 79 | * |
| 80 | * @dentry - object to perform setxattr on |
| 81 | * @name - xattr name to set |
| 82 | * @value - value to set @name to |
| 83 | * @size - size of @value |
| 84 | * @flags - flags to pass into filesystem operations |
| 85 | * |
| 86 | * returns the result of the internal setxattr or setsecurity operations. |
| 87 | * |
| 88 | * This function requires the caller to lock the inode's i_mutex before it |
| 89 | * is executed. It also assumes that the caller will make the appropriate |
| 90 | * permission checks. |
| 91 | */ |
| 92 | int __vfs_setxattr_noperm(struct dentry *dentry, const char *name, |
| 93 | const void *value, size_t size, int flags) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 94 | { |
| 95 | struct inode *inode = dentry->d_inode; |
David P. Quigley | b1ab7e4 | 2009-09-03 14:25:56 -0400 | [diff] [blame] | 96 | int error = -EOPNOTSUPP; |
Andi Kleen | 69b4573 | 2011-05-28 08:25:51 -0700 | [diff] [blame] | 97 | int issec = !strncmp(name, XATTR_SECURITY_PREFIX, |
| 98 | XATTR_SECURITY_PREFIX_LEN); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 99 | |
Andi Kleen | 69b4573 | 2011-05-28 08:25:51 -0700 | [diff] [blame] | 100 | if (issec) |
| 101 | inode->i_flags &= ~S_NOSEC; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 102 | if (inode->i_op->setxattr) { |
| 103 | error = inode->i_op->setxattr(dentry, name, value, size, flags); |
| 104 | if (!error) { |
| 105 | fsnotify_xattr(dentry); |
| 106 | security_inode_post_setxattr(dentry, name, value, |
| 107 | size, flags); |
| 108 | } |
Andi Kleen | 69b4573 | 2011-05-28 08:25:51 -0700 | [diff] [blame] | 109 | } else if (issec) { |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 110 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 111 | error = security_inode_setsecurity(inode, suffix, value, |
| 112 | size, flags); |
| 113 | if (!error) |
| 114 | fsnotify_xattr(dentry); |
| 115 | } |
David P. Quigley | b1ab7e4 | 2009-09-03 14:25:56 -0400 | [diff] [blame] | 116 | |
| 117 | return error; |
| 118 | } |
| 119 | |
| 120 | |
| 121 | int |
| 122 | vfs_setxattr(struct dentry *dentry, const char *name, const void *value, |
| 123 | size_t size, int flags) |
| 124 | { |
| 125 | struct inode *inode = dentry->d_inode; |
| 126 | int error; |
| 127 | |
| 128 | error = xattr_permission(inode, name, MAY_WRITE); |
| 129 | if (error) |
| 130 | return error; |
| 131 | |
| 132 | mutex_lock(&inode->i_mutex); |
| 133 | error = security_inode_setxattr(dentry, name, value, size, flags); |
| 134 | if (error) |
| 135 | goto out; |
| 136 | |
| 137 | error = __vfs_setxattr_noperm(dentry, name, value, size, flags); |
| 138 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 139 | out: |
| 140 | mutex_unlock(&inode->i_mutex); |
| 141 | return error; |
| 142 | } |
| 143 | EXPORT_SYMBOL_GPL(vfs_setxattr); |
| 144 | |
| 145 | ssize_t |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 146 | xattr_getsecurity(struct inode *inode, const char *name, void *value, |
| 147 | size_t size) |
| 148 | { |
| 149 | void *buffer = NULL; |
| 150 | ssize_t len; |
| 151 | |
| 152 | if (!value || !size) { |
| 153 | len = security_inode_getsecurity(inode, name, &buffer, false); |
| 154 | goto out_noalloc; |
| 155 | } |
| 156 | |
| 157 | len = security_inode_getsecurity(inode, name, &buffer, true); |
| 158 | if (len < 0) |
| 159 | return len; |
| 160 | if (size < len) { |
| 161 | len = -ERANGE; |
| 162 | goto out; |
| 163 | } |
| 164 | memcpy(value, buffer, len); |
| 165 | out: |
Casey Schaufler | dd1f96a | 2017-09-19 09:39:08 -0700 | [diff] [blame] | 166 | kfree(buffer); |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 167 | out_noalloc: |
| 168 | return len; |
| 169 | } |
| 170 | EXPORT_SYMBOL_GPL(xattr_getsecurity); |
| 171 | |
Mimi Zohar | 1601fba | 2011-03-09 14:23:34 -0500 | [diff] [blame] | 172 | /* |
| 173 | * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr |
| 174 | * |
| 175 | * Allocate memory, if not already allocated, or re-allocate correct size, |
| 176 | * before retrieving the extended attribute. |
| 177 | * |
| 178 | * Returns the result of alloc, if failed, or the getxattr operation. |
| 179 | */ |
| 180 | ssize_t |
| 181 | vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, |
| 182 | size_t xattr_size, gfp_t flags) |
| 183 | { |
| 184 | struct inode *inode = dentry->d_inode; |
| 185 | char *value = *xattr_value; |
| 186 | int error; |
| 187 | |
| 188 | error = xattr_permission(inode, name, MAY_READ); |
| 189 | if (error) |
| 190 | return error; |
| 191 | |
| 192 | if (!inode->i_op->getxattr) |
| 193 | return -EOPNOTSUPP; |
| 194 | |
| 195 | error = inode->i_op->getxattr(dentry, name, NULL, 0); |
| 196 | if (error < 0) |
| 197 | return error; |
| 198 | |
| 199 | if (!value || (error > xattr_size)) { |
| 200 | value = krealloc(*xattr_value, error + 1, flags); |
| 201 | if (!value) |
| 202 | return -ENOMEM; |
| 203 | memset(value, 0, error + 1); |
| 204 | } |
| 205 | |
| 206 | error = inode->i_op->getxattr(dentry, name, value, error); |
| 207 | *xattr_value = value; |
| 208 | return error; |
| 209 | } |
| 210 | |
| 211 | /* Compare an extended attribute value with the given value */ |
| 212 | int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name, |
| 213 | const char *value, size_t size, gfp_t flags) |
| 214 | { |
| 215 | char *xattr_value = NULL; |
| 216 | int rc; |
| 217 | |
| 218 | rc = vfs_getxattr_alloc(dentry, xattr_name, &xattr_value, 0, flags); |
| 219 | if (rc < 0) |
| 220 | return rc; |
| 221 | |
| 222 | if ((rc != size) || (memcmp(xattr_value, value, rc) != 0)) |
| 223 | rc = -EINVAL; |
| 224 | else |
| 225 | rc = 0; |
| 226 | kfree(xattr_value); |
| 227 | return rc; |
| 228 | } |
| 229 | |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 230 | ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 231 | vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 232 | { |
| 233 | struct inode *inode = dentry->d_inode; |
| 234 | int error; |
| 235 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 236 | error = xattr_permission(inode, name, MAY_READ); |
| 237 | if (error) |
| 238 | return error; |
| 239 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 240 | error = security_inode_getxattr(dentry, name); |
| 241 | if (error) |
| 242 | return error; |
| 243 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 244 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 245 | XATTR_SECURITY_PREFIX_LEN)) { |
| 246 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 247 | int ret = xattr_getsecurity(inode, suffix, value, size); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 248 | /* |
| 249 | * Only overwrite the return value if a security module |
| 250 | * is actually active. |
| 251 | */ |
David P. Quigley | 4bea580 | 2008-02-04 22:29:40 -0800 | [diff] [blame] | 252 | if (ret == -EOPNOTSUPP) |
| 253 | goto nolsm; |
| 254 | return ret; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 255 | } |
David P. Quigley | 4bea580 | 2008-02-04 22:29:40 -0800 | [diff] [blame] | 256 | nolsm: |
| 257 | if (inode->i_op->getxattr) |
| 258 | error = inode->i_op->getxattr(dentry, name, value, size); |
| 259 | else |
| 260 | error = -EOPNOTSUPP; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 261 | |
| 262 | return error; |
| 263 | } |
| 264 | EXPORT_SYMBOL_GPL(vfs_getxattr); |
| 265 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 266 | ssize_t |
| 267 | vfs_listxattr(struct dentry *d, char *list, size_t size) |
| 268 | { |
| 269 | ssize_t error; |
| 270 | |
| 271 | error = security_inode_listxattr(d); |
| 272 | if (error) |
| 273 | return error; |
| 274 | error = -EOPNOTSUPP; |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 275 | if (d->d_inode->i_op->listxattr) { |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 276 | error = d->d_inode->i_op->listxattr(d, list, size); |
| 277 | } else { |
| 278 | error = security_inode_listsecurity(d->d_inode, list, size); |
| 279 | if (size && error > size) |
| 280 | error = -ERANGE; |
| 281 | } |
| 282 | return error; |
| 283 | } |
| 284 | EXPORT_SYMBOL_GPL(vfs_listxattr); |
| 285 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 286 | int |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 287 | vfs_removexattr(struct dentry *dentry, const char *name) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 288 | { |
| 289 | struct inode *inode = dentry->d_inode; |
| 290 | int error; |
| 291 | |
| 292 | if (!inode->i_op->removexattr) |
| 293 | return -EOPNOTSUPP; |
| 294 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 295 | error = xattr_permission(inode, name, MAY_WRITE); |
| 296 | if (error) |
| 297 | return error; |
| 298 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 299 | mutex_lock(&inode->i_mutex); |
Mimi Zohar | 2ab51f3 | 2011-03-23 17:23:06 -0400 | [diff] [blame] | 300 | error = security_inode_removexattr(dentry, name); |
Dmitry Kasatkin | 7c51bb0 | 2014-11-20 16:31:01 +0200 | [diff] [blame] | 301 | if (error) |
| 302 | goto out; |
Mimi Zohar | 2ab51f3 | 2011-03-23 17:23:06 -0400 | [diff] [blame] | 303 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 304 | error = inode->i_op->removexattr(dentry, name); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 305 | |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 306 | if (!error) { |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 307 | fsnotify_xattr(dentry); |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 308 | evm_inode_post_removexattr(dentry, name); |
| 309 | } |
Dmitry Kasatkin | 7c51bb0 | 2014-11-20 16:31:01 +0200 | [diff] [blame] | 310 | |
| 311 | out: |
| 312 | mutex_unlock(&inode->i_mutex); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 313 | return error; |
| 314 | } |
| 315 | EXPORT_SYMBOL_GPL(vfs_removexattr); |
| 316 | |
| 317 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | /* |
| 319 | * Extended attribute SET operations |
| 320 | */ |
| 321 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 322 | setxattr(struct dentry *d, const char __user *name, const void __user *value, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | size_t size, int flags) |
| 324 | { |
| 325 | int error; |
| 326 | void *kvalue = NULL; |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 327 | void *vvalue = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | char kname[XATTR_NAME_MAX + 1]; |
| 329 | |
| 330 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) |
| 331 | return -EINVAL; |
| 332 | |
| 333 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 334 | if (error == 0 || error == sizeof(kname)) |
| 335 | error = -ERANGE; |
| 336 | if (error < 0) |
| 337 | return error; |
| 338 | |
| 339 | if (size) { |
| 340 | if (size > XATTR_SIZE_MAX) |
| 341 | return -E2BIG; |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 342 | kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| 343 | if (!kvalue) { |
| 344 | vvalue = vmalloc(size); |
| 345 | if (!vvalue) |
| 346 | return -ENOMEM; |
| 347 | kvalue = vvalue; |
| 348 | } |
| 349 | if (copy_from_user(kvalue, value, size)) { |
| 350 | error = -EFAULT; |
| 351 | goto out; |
| 352 | } |
Eric W. Biederman | 2f6f065 | 2012-02-07 18:52:57 -0800 | [diff] [blame] | 353 | if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
| 354 | (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) |
| 355 | posix_acl_fix_xattr_from_user(kvalue, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | } |
| 357 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 358 | error = vfs_setxattr(d, kname, kvalue, size, flags); |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 359 | out: |
| 360 | if (vvalue) |
| 361 | vfree(vvalue); |
| 362 | else |
| 363 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | return error; |
| 365 | } |
| 366 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 367 | static int path_setxattr(const char __user *pathname, |
| 368 | const char __user *name, const void __user *value, |
| 369 | size_t size, int flags, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 371 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | int error; |
Jeff Layton | 68f1bb8 | 2012-12-11 12:10:15 -0500 | [diff] [blame] | 373 | retry: |
| 374 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | if (error) |
| 376 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 377 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 378 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 379 | error = setxattr(path.dentry, name, value, size, flags); |
| 380 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 381 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 382 | path_put(&path); |
Jeff Layton | 68f1bb8 | 2012-12-11 12:10:15 -0500 | [diff] [blame] | 383 | if (retry_estale(error, lookup_flags)) { |
| 384 | lookup_flags |= LOOKUP_REVAL; |
| 385 | goto retry; |
| 386 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | return error; |
| 388 | } |
| 389 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 390 | SYSCALL_DEFINE5(setxattr, const char __user *, pathname, |
| 391 | const char __user *, name, const void __user *, value, |
| 392 | size_t, size, int, flags) |
| 393 | { |
| 394 | return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW); |
| 395 | } |
| 396 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 397 | SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, |
| 398 | const char __user *, name, const void __user *, value, |
| 399 | size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 401 | return path_setxattr(pathname, name, value, size, flags, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | } |
| 403 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 404 | SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, |
| 405 | const void __user *,value, size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 407 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | int error = -EBADF; |
| 409 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 410 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 412 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 413 | error = mnt_want_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 414 | if (!error) { |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 415 | error = setxattr(f.file->f_path.dentry, name, value, size, flags); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 416 | mnt_drop_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 417 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 418 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | return error; |
| 420 | } |
| 421 | |
| 422 | /* |
| 423 | * Extended attribute GET operations |
| 424 | */ |
| 425 | static ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 426 | getxattr(struct dentry *d, const char __user *name, void __user *value, |
| 427 | size_t size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | { |
| 429 | ssize_t error; |
| 430 | void *kvalue = NULL; |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 431 | void *vvalue = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | char kname[XATTR_NAME_MAX + 1]; |
| 433 | |
| 434 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 435 | if (error == 0 || error == sizeof(kname)) |
| 436 | error = -ERANGE; |
| 437 | if (error < 0) |
| 438 | return error; |
| 439 | |
| 440 | if (size) { |
| 441 | if (size > XATTR_SIZE_MAX) |
| 442 | size = XATTR_SIZE_MAX; |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 443 | kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| 444 | if (!kvalue) { |
Michal Hocko | eb04a73 | 2017-05-08 15:57:24 -0700 | [diff] [blame] | 445 | vvalue = vzalloc(size); |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 446 | if (!vvalue) |
| 447 | return -ENOMEM; |
| 448 | kvalue = vvalue; |
| 449 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | } |
| 451 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 452 | error = vfs_getxattr(d, kname, kvalue, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 453 | if (error > 0) { |
Eric W. Biederman | 2f6f065 | 2012-02-07 18:52:57 -0800 | [diff] [blame] | 454 | if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
| 455 | (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) |
Christian Brauner | f7f501c | 2018-06-07 13:43:48 +0200 | [diff] [blame] | 456 | posix_acl_fix_xattr_to_user(kvalue, error); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 457 | if (size && copy_to_user(value, kvalue, error)) |
| 458 | error = -EFAULT; |
| 459 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { |
| 460 | /* The file system tried to returned a value bigger |
| 461 | than XATTR_SIZE_MAX bytes. Not possible. */ |
| 462 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 464 | if (vvalue) |
| 465 | vfree(vvalue); |
| 466 | else |
| 467 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | return error; |
| 469 | } |
| 470 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 471 | static ssize_t path_getxattr(const char __user *pathname, |
| 472 | const char __user *name, void __user *value, |
| 473 | size_t size, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 475 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | ssize_t error; |
Jeff Layton | 60e66b4 | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 477 | retry: |
| 478 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | if (error) |
| 480 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 481 | error = getxattr(path.dentry, name, value, size); |
| 482 | path_put(&path); |
Jeff Layton | 60e66b4 | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 483 | if (retry_estale(error, lookup_flags)) { |
| 484 | lookup_flags |= LOOKUP_REVAL; |
| 485 | goto retry; |
| 486 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | return error; |
| 488 | } |
| 489 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 490 | SYSCALL_DEFINE4(getxattr, const char __user *, pathname, |
| 491 | const char __user *, name, void __user *, value, size_t, size) |
| 492 | { |
| 493 | return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW); |
| 494 | } |
| 495 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 496 | SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, |
| 497 | const char __user *, name, void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 499 | return path_getxattr(pathname, name, value, size, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | } |
| 501 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 502 | SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, |
| 503 | void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 505 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | ssize_t error = -EBADF; |
| 507 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 508 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 510 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 511 | error = getxattr(f.file->f_path.dentry, name, value, size); |
| 512 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | return error; |
| 514 | } |
| 515 | |
| 516 | /* |
| 517 | * Extended attribute LIST operations |
| 518 | */ |
| 519 | static ssize_t |
| 520 | listxattr(struct dentry *d, char __user *list, size_t size) |
| 521 | { |
| 522 | ssize_t error; |
| 523 | char *klist = NULL; |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 524 | char *vlist = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | |
| 526 | if (size) { |
| 527 | if (size > XATTR_LIST_MAX) |
| 528 | size = XATTR_LIST_MAX; |
Dave Jones | 703bf2d | 2012-04-05 14:25:06 -0700 | [diff] [blame] | 529 | klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 530 | if (!klist) { |
| 531 | vlist = vmalloc(size); |
| 532 | if (!vlist) |
| 533 | return -ENOMEM; |
| 534 | klist = vlist; |
| 535 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | } |
| 537 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 538 | error = vfs_listxattr(d, klist, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 539 | if (error > 0) { |
| 540 | if (size && copy_to_user(list, klist, error)) |
| 541 | error = -EFAULT; |
| 542 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { |
| 543 | /* The file system tried to returned a list bigger |
| 544 | than XATTR_LIST_MAX bytes. Not possible. */ |
| 545 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | } |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 547 | if (vlist) |
| 548 | vfree(vlist); |
| 549 | else |
| 550 | kfree(klist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | return error; |
| 552 | } |
| 553 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 554 | static ssize_t path_listxattr(const char __user *pathname, char __user *list, |
| 555 | size_t size, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 557 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | ssize_t error; |
Jeff Layton | 10a90cf | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 559 | retry: |
| 560 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | if (error) |
| 562 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 563 | error = listxattr(path.dentry, list, size); |
| 564 | path_put(&path); |
Jeff Layton | 10a90cf | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 565 | if (retry_estale(error, lookup_flags)) { |
| 566 | lookup_flags |= LOOKUP_REVAL; |
| 567 | goto retry; |
| 568 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | return error; |
| 570 | } |
| 571 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 572 | SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, |
| 573 | size_t, size) |
| 574 | { |
| 575 | return path_listxattr(pathname, list, size, LOOKUP_FOLLOW); |
| 576 | } |
| 577 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 578 | SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, |
| 579 | size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 581 | return path_listxattr(pathname, list, size, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | } |
| 583 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 584 | SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 586 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | ssize_t error = -EBADF; |
| 588 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 589 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 591 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 592 | error = listxattr(f.file->f_path.dentry, list, size); |
| 593 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | return error; |
| 595 | } |
| 596 | |
| 597 | /* |
| 598 | * Extended attribute REMOVE operations |
| 599 | */ |
| 600 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 601 | removexattr(struct dentry *d, const char __user *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | { |
| 603 | int error; |
| 604 | char kname[XATTR_NAME_MAX + 1]; |
| 605 | |
| 606 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 607 | if (error == 0 || error == sizeof(kname)) |
| 608 | error = -ERANGE; |
| 609 | if (error < 0) |
| 610 | return error; |
| 611 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 612 | return vfs_removexattr(d, kname); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | } |
| 614 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 615 | static int path_removexattr(const char __user *pathname, |
| 616 | const char __user *name, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 618 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | int error; |
Jeff Layton | 12f0621 | 2012-12-11 12:10:17 -0500 | [diff] [blame] | 620 | retry: |
| 621 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | if (error) |
| 623 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 624 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 625 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 626 | error = removexattr(path.dentry, name); |
| 627 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 628 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 629 | path_put(&path); |
Jeff Layton | 12f0621 | 2012-12-11 12:10:17 -0500 | [diff] [blame] | 630 | if (retry_estale(error, lookup_flags)) { |
| 631 | lookup_flags |= LOOKUP_REVAL; |
| 632 | goto retry; |
| 633 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | return error; |
| 635 | } |
| 636 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 637 | SYSCALL_DEFINE2(removexattr, const char __user *, pathname, |
| 638 | const char __user *, name) |
| 639 | { |
| 640 | return path_removexattr(pathname, name, LOOKUP_FOLLOW); |
| 641 | } |
| 642 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 643 | SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, |
| 644 | const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 646 | return path_removexattr(pathname, name, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | } |
| 648 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 649 | SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 651 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | int error = -EBADF; |
| 653 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 654 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 656 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 657 | error = mnt_want_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 658 | if (!error) { |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 659 | error = removexattr(f.file->f_path.dentry, name); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 660 | mnt_drop_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 661 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 662 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | return error; |
| 664 | } |
| 665 | |
| 666 | |
| 667 | static const char * |
| 668 | strcmp_prefix(const char *a, const char *a_prefix) |
| 669 | { |
| 670 | while (*a_prefix && *a == *a_prefix) { |
| 671 | a++; |
| 672 | a_prefix++; |
| 673 | } |
| 674 | return *a_prefix ? NULL : a; |
| 675 | } |
| 676 | |
| 677 | /* |
| 678 | * In order to implement different sets of xattr operations for each xattr |
| 679 | * prefix with the generic xattr API, a filesystem should create a |
| 680 | * null-terminated array of struct xattr_handler (one for each prefix) and |
| 681 | * hang a pointer to it off of the s_xattr field of the superblock. |
| 682 | * |
| 683 | * The generic_fooxattr() functions will use this list to dispatch xattr |
| 684 | * operations to the correct xattr_handler. |
| 685 | */ |
| 686 | #define for_each_xattr_handler(handlers, handler) \ |
| 687 | for ((handler) = *(handlers)++; \ |
| 688 | (handler) != NULL; \ |
| 689 | (handler) = *(handlers)++) |
| 690 | |
| 691 | /* |
| 692 | * Find the xattr_handler with the matching prefix. |
| 693 | */ |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 694 | static const struct xattr_handler * |
| 695 | xattr_resolve_name(const struct xattr_handler **handlers, const char **name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 697 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
| 699 | if (!*name) |
| 700 | return NULL; |
| 701 | |
| 702 | for_each_xattr_handler(handlers, handler) { |
| 703 | const char *n = strcmp_prefix(*name, handler->prefix); |
| 704 | if (n) { |
| 705 | *name = n; |
| 706 | break; |
| 707 | } |
| 708 | } |
| 709 | return handler; |
| 710 | } |
| 711 | |
| 712 | /* |
| 713 | * Find the handler for the prefix and dispatch its get() operation. |
| 714 | */ |
| 715 | ssize_t |
| 716 | generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size) |
| 717 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 718 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 720 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | if (!handler) |
| 722 | return -EOPNOTSUPP; |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 723 | return handler->get(handler, dentry, name, buffer, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
| 725 | |
| 726 | /* |
| 727 | * Combine the results of the list() operation from every xattr_handler in the |
| 728 | * list. |
| 729 | */ |
| 730 | ssize_t |
| 731 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) |
| 732 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 733 | const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | unsigned int size = 0; |
| 735 | |
| 736 | if (!buffer) { |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 737 | for_each_xattr_handler(handlers, handler) { |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 738 | size += handler->list(handler, dentry, NULL, 0, |
| 739 | NULL, 0); |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 740 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | } else { |
| 742 | char *buf = buffer; |
| 743 | |
| 744 | for_each_xattr_handler(handlers, handler) { |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 745 | size = handler->list(handler, dentry, buf, buffer_size, |
| 746 | NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | if (size > buffer_size) |
| 748 | return -ERANGE; |
| 749 | buf += size; |
| 750 | buffer_size -= size; |
| 751 | } |
| 752 | size = buf - buffer; |
| 753 | } |
| 754 | return size; |
| 755 | } |
| 756 | |
| 757 | /* |
| 758 | * Find the handler for the prefix and dispatch its set() operation. |
| 759 | */ |
| 760 | int |
| 761 | generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) |
| 762 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 763 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | |
| 765 | if (size == 0) |
| 766 | value = ""; /* empty EA, do not remove */ |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 767 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | if (!handler) |
| 769 | return -EOPNOTSUPP; |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 770 | return handler->set(handler, dentry, name, value, size, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | } |
| 772 | |
| 773 | /* |
| 774 | * Find the handler for the prefix and dispatch its set() operation to remove |
| 775 | * any associated extended attribute. |
| 776 | */ |
| 777 | int |
| 778 | generic_removexattr(struct dentry *dentry, const char *name) |
| 779 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 780 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 782 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | if (!handler) |
| 784 | return -EOPNOTSUPP; |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 785 | return handler->set(handler, dentry, name, NULL, 0, XATTR_REPLACE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | } |
| 787 | |
| 788 | EXPORT_SYMBOL(generic_getxattr); |
| 789 | EXPORT_SYMBOL(generic_listxattr); |
| 790 | EXPORT_SYMBOL(generic_setxattr); |
| 791 | EXPORT_SYMBOL(generic_removexattr); |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 792 | |
Andreas Gruenbacher | e409de9 | 2015-10-04 19:18:52 +0200 | [diff] [blame] | 793 | /** |
| 794 | * xattr_full_name - Compute full attribute name from suffix |
| 795 | * |
| 796 | * @handler: handler of the xattr_handler operation |
| 797 | * @name: name passed to the xattr_handler operation |
| 798 | * |
| 799 | * The get and set xattr handler operations are called with the remainder of |
| 800 | * the attribute name after skipping the handler's prefix: for example, "foo" |
| 801 | * is passed to the get operation of a handler with prefix "user." to get |
| 802 | * attribute "user.foo". The full name is still "there" in the name though. |
| 803 | * |
| 804 | * Note: the list xattr handler operation when called from the vfs is passed a |
| 805 | * NULL name; some file systems use this operation internally, with varying |
| 806 | * semantics. |
| 807 | */ |
| 808 | const char *xattr_full_name(const struct xattr_handler *handler, |
| 809 | const char *name) |
| 810 | { |
| 811 | size_t prefix_len = strlen(handler->prefix); |
| 812 | |
| 813 | return name - prefix_len; |
| 814 | } |
| 815 | EXPORT_SYMBOL(xattr_full_name); |
| 816 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 817 | /* |
| 818 | * Allocate new xattr and copy in the value; but leave the name to callers. |
| 819 | */ |
| 820 | struct simple_xattr *simple_xattr_alloc(const void *value, size_t size) |
| 821 | { |
| 822 | struct simple_xattr *new_xattr; |
| 823 | size_t len; |
| 824 | |
| 825 | /* wrap around? */ |
| 826 | len = sizeof(*new_xattr) + size; |
Hugh Dickins | 4e66d44 | 2014-07-23 14:00:17 -0700 | [diff] [blame] | 827 | if (len < sizeof(*new_xattr)) |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 828 | return NULL; |
| 829 | |
| 830 | new_xattr = kmalloc(len, GFP_KERNEL); |
| 831 | if (!new_xattr) |
| 832 | return NULL; |
| 833 | |
| 834 | new_xattr->size = size; |
| 835 | memcpy(new_xattr->value, value, size); |
| 836 | return new_xattr; |
| 837 | } |
| 838 | |
| 839 | /* |
| 840 | * xattr GET operation for in-memory/pseudo filesystems |
| 841 | */ |
| 842 | int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, |
| 843 | void *buffer, size_t size) |
| 844 | { |
| 845 | struct simple_xattr *xattr; |
| 846 | int ret = -ENODATA; |
| 847 | |
| 848 | spin_lock(&xattrs->lock); |
| 849 | list_for_each_entry(xattr, &xattrs->head, list) { |
| 850 | if (strcmp(name, xattr->name)) |
| 851 | continue; |
| 852 | |
| 853 | ret = xattr->size; |
| 854 | if (buffer) { |
| 855 | if (size < xattr->size) |
| 856 | ret = -ERANGE; |
| 857 | else |
| 858 | memcpy(buffer, xattr->value, xattr->size); |
| 859 | } |
| 860 | break; |
| 861 | } |
| 862 | spin_unlock(&xattrs->lock); |
| 863 | return ret; |
| 864 | } |
| 865 | |
| 866 | static int __simple_xattr_set(struct simple_xattrs *xattrs, const char *name, |
| 867 | const void *value, size_t size, int flags) |
| 868 | { |
| 869 | struct simple_xattr *xattr; |
David Rientjes | 4338584 | 2012-10-17 20:41:15 -0700 | [diff] [blame] | 870 | struct simple_xattr *new_xattr = NULL; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 871 | int err = 0; |
| 872 | |
| 873 | /* value == NULL means remove */ |
| 874 | if (value) { |
| 875 | new_xattr = simple_xattr_alloc(value, size); |
| 876 | if (!new_xattr) |
| 877 | return -ENOMEM; |
| 878 | |
| 879 | new_xattr->name = kstrdup(name, GFP_KERNEL); |
| 880 | if (!new_xattr->name) { |
| 881 | kfree(new_xattr); |
| 882 | return -ENOMEM; |
| 883 | } |
| 884 | } |
| 885 | |
| 886 | spin_lock(&xattrs->lock); |
| 887 | list_for_each_entry(xattr, &xattrs->head, list) { |
| 888 | if (!strcmp(name, xattr->name)) { |
| 889 | if (flags & XATTR_CREATE) { |
| 890 | xattr = new_xattr; |
| 891 | err = -EEXIST; |
| 892 | } else if (new_xattr) { |
| 893 | list_replace(&xattr->list, &new_xattr->list); |
| 894 | } else { |
| 895 | list_del(&xattr->list); |
| 896 | } |
| 897 | goto out; |
| 898 | } |
| 899 | } |
| 900 | if (flags & XATTR_REPLACE) { |
| 901 | xattr = new_xattr; |
| 902 | err = -ENODATA; |
| 903 | } else { |
| 904 | list_add(&new_xattr->list, &xattrs->head); |
| 905 | xattr = NULL; |
| 906 | } |
| 907 | out: |
| 908 | spin_unlock(&xattrs->lock); |
| 909 | if (xattr) { |
| 910 | kfree(xattr->name); |
| 911 | kfree(xattr); |
| 912 | } |
| 913 | return err; |
| 914 | |
| 915 | } |
| 916 | |
Aristeu Rozanski | 4895768 | 2012-09-11 16:28:11 -0400 | [diff] [blame] | 917 | /** |
| 918 | * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems |
| 919 | * @xattrs: target simple_xattr list |
| 920 | * @name: name of the new extended attribute |
| 921 | * @value: value of the new xattr. If %NULL, will remove the attribute |
| 922 | * @size: size of the new xattr |
| 923 | * @flags: %XATTR_{CREATE|REPLACE} |
| 924 | * |
| 925 | * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails |
| 926 | * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist; |
| 927 | * otherwise, fails with -ENODATA. |
| 928 | * |
| 929 | * Returns 0 on success, -errno on failure. |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 930 | */ |
| 931 | int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, |
| 932 | const void *value, size_t size, int flags) |
| 933 | { |
| 934 | if (size == 0) |
| 935 | value = ""; /* empty EA, do not remove */ |
| 936 | return __simple_xattr_set(xattrs, name, value, size, flags); |
| 937 | } |
| 938 | |
| 939 | /* |
| 940 | * xattr REMOVE operation for in-memory/pseudo filesystems |
| 941 | */ |
| 942 | int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name) |
| 943 | { |
| 944 | return __simple_xattr_set(xattrs, name, NULL, 0, XATTR_REPLACE); |
| 945 | } |
| 946 | |
| 947 | static bool xattr_is_trusted(const char *name) |
| 948 | { |
| 949 | return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN); |
| 950 | } |
| 951 | |
| 952 | /* |
| 953 | * xattr LIST operation for in-memory/pseudo filesystems |
| 954 | */ |
| 955 | ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer, |
| 956 | size_t size) |
| 957 | { |
| 958 | bool trusted = capable(CAP_SYS_ADMIN); |
| 959 | struct simple_xattr *xattr; |
| 960 | size_t used = 0; |
| 961 | |
| 962 | spin_lock(&xattrs->lock); |
| 963 | list_for_each_entry(xattr, &xattrs->head, list) { |
| 964 | size_t len; |
| 965 | |
| 966 | /* skip "trusted." attributes for unprivileged callers */ |
| 967 | if (!trusted && xattr_is_trusted(xattr->name)) |
| 968 | continue; |
| 969 | |
| 970 | len = strlen(xattr->name) + 1; |
| 971 | used += len; |
| 972 | if (buffer) { |
| 973 | if (size < used) { |
| 974 | used = -ERANGE; |
| 975 | break; |
| 976 | } |
| 977 | memcpy(buffer, xattr->name, len); |
| 978 | buffer += len; |
| 979 | } |
| 980 | } |
| 981 | spin_unlock(&xattrs->lock); |
| 982 | |
| 983 | return used; |
| 984 | } |
| 985 | |
Aristeu Rozanski | 4895768 | 2012-09-11 16:28:11 -0400 | [diff] [blame] | 986 | /* |
| 987 | * Adds an extended attribute to the list |
| 988 | */ |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 989 | void simple_xattr_list_add(struct simple_xattrs *xattrs, |
| 990 | struct simple_xattr *new_xattr) |
| 991 | { |
| 992 | spin_lock(&xattrs->lock); |
| 993 | list_add(&new_xattr->list, &xattrs->head); |
| 994 | spin_unlock(&xattrs->lock); |
| 995 | } |