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 | |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 73 | return inode_permission(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: |
| 166 | security_release_secctx(buffer, len); |
| 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 | |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 211 | ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 212 | 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] | 213 | { |
| 214 | struct inode *inode = dentry->d_inode; |
| 215 | int error; |
| 216 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 217 | error = xattr_permission(inode, name, MAY_READ); |
| 218 | if (error) |
| 219 | return error; |
| 220 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 221 | error = security_inode_getxattr(dentry, name); |
| 222 | if (error) |
| 223 | return error; |
| 224 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 225 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 226 | XATTR_SECURITY_PREFIX_LEN)) { |
| 227 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 228 | int ret = xattr_getsecurity(inode, suffix, value, size); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 229 | /* |
| 230 | * Only overwrite the return value if a security module |
| 231 | * is actually active. |
| 232 | */ |
David P. Quigley | 4bea580 | 2008-02-04 22:29:40 -0800 | [diff] [blame] | 233 | if (ret == -EOPNOTSUPP) |
| 234 | goto nolsm; |
| 235 | return ret; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 236 | } |
David P. Quigley | 4bea580 | 2008-02-04 22:29:40 -0800 | [diff] [blame] | 237 | nolsm: |
| 238 | if (inode->i_op->getxattr) |
| 239 | error = inode->i_op->getxattr(dentry, name, value, size); |
| 240 | else |
| 241 | error = -EOPNOTSUPP; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 242 | |
| 243 | return error; |
| 244 | } |
| 245 | EXPORT_SYMBOL_GPL(vfs_getxattr); |
| 246 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 247 | ssize_t |
| 248 | vfs_listxattr(struct dentry *d, char *list, size_t size) |
| 249 | { |
| 250 | ssize_t error; |
| 251 | |
| 252 | error = security_inode_listxattr(d); |
| 253 | if (error) |
| 254 | return error; |
| 255 | error = -EOPNOTSUPP; |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 256 | if (d->d_inode->i_op->listxattr) { |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 257 | error = d->d_inode->i_op->listxattr(d, list, size); |
| 258 | } else { |
| 259 | error = security_inode_listsecurity(d->d_inode, list, size); |
| 260 | if (size && error > size) |
| 261 | error = -ERANGE; |
| 262 | } |
| 263 | return error; |
| 264 | } |
| 265 | EXPORT_SYMBOL_GPL(vfs_listxattr); |
| 266 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 267 | int |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 268 | vfs_removexattr(struct dentry *dentry, const char *name) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 269 | { |
| 270 | struct inode *inode = dentry->d_inode; |
| 271 | int error; |
| 272 | |
| 273 | if (!inode->i_op->removexattr) |
| 274 | return -EOPNOTSUPP; |
| 275 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 276 | error = xattr_permission(inode, name, MAY_WRITE); |
| 277 | if (error) |
| 278 | return error; |
| 279 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 280 | mutex_lock(&inode->i_mutex); |
Mimi Zohar | 2ab51f3 | 2011-03-23 17:23:06 -0400 | [diff] [blame] | 281 | error = security_inode_removexattr(dentry, name); |
Dmitry Kasatkin | 7c51bb0 | 2014-11-20 16:31:01 +0200 | [diff] [blame] | 282 | if (error) |
| 283 | goto out; |
Mimi Zohar | 2ab51f3 | 2011-03-23 17:23:06 -0400 | [diff] [blame] | 284 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 285 | error = inode->i_op->removexattr(dentry, name); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 286 | |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 287 | if (!error) { |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 288 | fsnotify_xattr(dentry); |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 289 | evm_inode_post_removexattr(dentry, name); |
| 290 | } |
Dmitry Kasatkin | 7c51bb0 | 2014-11-20 16:31:01 +0200 | [diff] [blame] | 291 | |
| 292 | out: |
| 293 | mutex_unlock(&inode->i_mutex); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 294 | return error; |
| 295 | } |
| 296 | EXPORT_SYMBOL_GPL(vfs_removexattr); |
| 297 | |
| 298 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | /* |
| 300 | * Extended attribute SET operations |
| 301 | */ |
| 302 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 303 | setxattr(struct dentry *d, const char __user *name, const void __user *value, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | size_t size, int flags) |
| 305 | { |
| 306 | int error; |
| 307 | void *kvalue = NULL; |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 308 | void *vvalue = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | char kname[XATTR_NAME_MAX + 1]; |
| 310 | |
| 311 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) |
| 312 | return -EINVAL; |
| 313 | |
| 314 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 315 | if (error == 0 || error == sizeof(kname)) |
| 316 | error = -ERANGE; |
| 317 | if (error < 0) |
| 318 | return error; |
| 319 | |
| 320 | if (size) { |
| 321 | if (size > XATTR_SIZE_MAX) |
| 322 | return -E2BIG; |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 323 | kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| 324 | if (!kvalue) { |
| 325 | vvalue = vmalloc(size); |
| 326 | if (!vvalue) |
| 327 | return -ENOMEM; |
| 328 | kvalue = vvalue; |
| 329 | } |
| 330 | if (copy_from_user(kvalue, value, size)) { |
| 331 | error = -EFAULT; |
| 332 | goto out; |
| 333 | } |
Eric W. Biederman | 2f6f065 | 2012-02-07 18:52:57 -0800 | [diff] [blame] | 334 | if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
| 335 | (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) |
| 336 | posix_acl_fix_xattr_from_user(kvalue, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | } |
| 338 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 339 | error = vfs_setxattr(d, kname, kvalue, size, flags); |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 340 | out: |
| 341 | if (vvalue) |
| 342 | vfree(vvalue); |
| 343 | else |
| 344 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | return error; |
| 346 | } |
| 347 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 348 | static int path_setxattr(const char __user *pathname, |
| 349 | const char __user *name, const void __user *value, |
| 350 | size_t size, int flags, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 352 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | int error; |
Jeff Layton | 68f1bb8 | 2012-12-11 12:10:15 -0500 | [diff] [blame] | 354 | retry: |
| 355 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | if (error) |
| 357 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 358 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 359 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 360 | error = setxattr(path.dentry, name, value, size, flags); |
| 361 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 362 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 363 | path_put(&path); |
Jeff Layton | 68f1bb8 | 2012-12-11 12:10:15 -0500 | [diff] [blame] | 364 | if (retry_estale(error, lookup_flags)) { |
| 365 | lookup_flags |= LOOKUP_REVAL; |
| 366 | goto retry; |
| 367 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | return error; |
| 369 | } |
| 370 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 371 | SYSCALL_DEFINE5(setxattr, const char __user *, pathname, |
| 372 | const char __user *, name, const void __user *, value, |
| 373 | size_t, size, int, flags) |
| 374 | { |
| 375 | return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW); |
| 376 | } |
| 377 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 378 | SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, |
| 379 | const char __user *, name, const void __user *, value, |
| 380 | size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 382 | return path_setxattr(pathname, name, value, size, flags, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | } |
| 384 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 385 | SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, |
| 386 | const void __user *,value, size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 388 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | int error = -EBADF; |
| 390 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 391 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 393 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 394 | error = mnt_want_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 395 | if (!error) { |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 396 | error = setxattr(f.file->f_path.dentry, name, value, size, flags); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 397 | mnt_drop_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 398 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 399 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | return error; |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * Extended attribute GET operations |
| 405 | */ |
| 406 | static ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 407 | getxattr(struct dentry *d, const char __user *name, void __user *value, |
| 408 | size_t size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | { |
| 410 | ssize_t error; |
| 411 | void *kvalue = NULL; |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 412 | void *vvalue = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | char kname[XATTR_NAME_MAX + 1]; |
| 414 | |
| 415 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 416 | if (error == 0 || error == sizeof(kname)) |
| 417 | error = -ERANGE; |
| 418 | if (error < 0) |
| 419 | return error; |
| 420 | |
| 421 | if (size) { |
| 422 | if (size > XATTR_SIZE_MAX) |
| 423 | size = XATTR_SIZE_MAX; |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 424 | kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| 425 | if (!kvalue) { |
| 426 | vvalue = vmalloc(size); |
| 427 | if (!vvalue) |
| 428 | return -ENOMEM; |
| 429 | kvalue = vvalue; |
| 430 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | } |
| 432 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 433 | error = vfs_getxattr(d, kname, kvalue, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 434 | if (error > 0) { |
Eric W. Biederman | 2f6f065 | 2012-02-07 18:52:57 -0800 | [diff] [blame] | 435 | if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
| 436 | (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) |
| 437 | posix_acl_fix_xattr_to_user(kvalue, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 438 | if (size && copy_to_user(value, kvalue, error)) |
| 439 | error = -EFAULT; |
| 440 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { |
| 441 | /* The file system tried to returned a value bigger |
| 442 | than XATTR_SIZE_MAX bytes. Not possible. */ |
| 443 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | } |
Sasha Levin | 779302e | 2012-07-30 14:39:13 -0700 | [diff] [blame] | 445 | if (vvalue) |
| 446 | vfree(vvalue); |
| 447 | else |
| 448 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | return error; |
| 450 | } |
| 451 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 452 | static ssize_t path_getxattr(const char __user *pathname, |
| 453 | const char __user *name, void __user *value, |
| 454 | size_t size, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 456 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | ssize_t error; |
Jeff Layton | 60e66b4 | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 458 | retry: |
| 459 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | if (error) |
| 461 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 462 | error = getxattr(path.dentry, name, value, size); |
| 463 | path_put(&path); |
Jeff Layton | 60e66b4 | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 464 | if (retry_estale(error, lookup_flags)) { |
| 465 | lookup_flags |= LOOKUP_REVAL; |
| 466 | goto retry; |
| 467 | } |
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 | SYSCALL_DEFINE4(getxattr, const char __user *, pathname, |
| 472 | const char __user *, name, void __user *, value, size_t, size) |
| 473 | { |
| 474 | return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW); |
| 475 | } |
| 476 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 477 | SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, |
| 478 | const char __user *, name, void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 480 | return path_getxattr(pathname, name, value, size, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | } |
| 482 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 483 | SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, |
| 484 | void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 486 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | ssize_t error = -EBADF; |
| 488 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 489 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 491 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 492 | error = getxattr(f.file->f_path.dentry, name, value, size); |
| 493 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | return error; |
| 495 | } |
| 496 | |
| 497 | /* |
| 498 | * Extended attribute LIST operations |
| 499 | */ |
| 500 | static ssize_t |
| 501 | listxattr(struct dentry *d, char __user *list, size_t size) |
| 502 | { |
| 503 | ssize_t error; |
| 504 | char *klist = NULL; |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 505 | char *vlist = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | |
| 507 | if (size) { |
| 508 | if (size > XATTR_LIST_MAX) |
| 509 | size = XATTR_LIST_MAX; |
Dave Jones | 703bf2d | 2012-04-05 14:25:06 -0700 | [diff] [blame] | 510 | klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 511 | if (!klist) { |
| 512 | vlist = vmalloc(size); |
| 513 | if (!vlist) |
| 514 | return -ENOMEM; |
| 515 | klist = vlist; |
| 516 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | } |
| 518 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 519 | error = vfs_listxattr(d, klist, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 520 | if (error > 0) { |
| 521 | if (size && copy_to_user(list, klist, error)) |
| 522 | error = -EFAULT; |
| 523 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { |
| 524 | /* The file system tried to returned a list bigger |
| 525 | than XATTR_LIST_MAX bytes. Not possible. */ |
| 526 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | } |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 528 | if (vlist) |
| 529 | vfree(vlist); |
| 530 | else |
| 531 | kfree(klist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | return error; |
| 533 | } |
| 534 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 535 | static ssize_t path_listxattr(const char __user *pathname, char __user *list, |
| 536 | size_t size, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 538 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | ssize_t error; |
Jeff Layton | 10a90cf | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 540 | retry: |
| 541 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | if (error) |
| 543 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 544 | error = listxattr(path.dentry, list, size); |
| 545 | path_put(&path); |
Jeff Layton | 10a90cf | 2012-12-11 12:10:16 -0500 | [diff] [blame] | 546 | if (retry_estale(error, lookup_flags)) { |
| 547 | lookup_flags |= LOOKUP_REVAL; |
| 548 | goto retry; |
| 549 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | return error; |
| 551 | } |
| 552 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 553 | SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, |
| 554 | size_t, size) |
| 555 | { |
| 556 | return path_listxattr(pathname, list, size, LOOKUP_FOLLOW); |
| 557 | } |
| 558 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 559 | SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, |
| 560 | size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 562 | return path_listxattr(pathname, list, size, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | } |
| 564 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 565 | SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 567 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | ssize_t error = -EBADF; |
| 569 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 570 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 572 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 573 | error = listxattr(f.file->f_path.dentry, list, size); |
| 574 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | return error; |
| 576 | } |
| 577 | |
| 578 | /* |
| 579 | * Extended attribute REMOVE operations |
| 580 | */ |
| 581 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 582 | removexattr(struct dentry *d, const char __user *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | { |
| 584 | int error; |
| 585 | char kname[XATTR_NAME_MAX + 1]; |
| 586 | |
| 587 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 588 | if (error == 0 || error == sizeof(kname)) |
| 589 | error = -ERANGE; |
| 590 | if (error < 0) |
| 591 | return error; |
| 592 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 593 | return vfs_removexattr(d, kname); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | } |
| 595 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 596 | static int path_removexattr(const char __user *pathname, |
| 597 | const char __user *name, unsigned int lookup_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 599 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | int error; |
Jeff Layton | 12f0621 | 2012-12-11 12:10:17 -0500 | [diff] [blame] | 601 | retry: |
| 602 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | if (error) |
| 604 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 605 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 606 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 607 | error = removexattr(path.dentry, name); |
| 608 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 609 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 610 | path_put(&path); |
Jeff Layton | 12f0621 | 2012-12-11 12:10:17 -0500 | [diff] [blame] | 611 | if (retry_estale(error, lookup_flags)) { |
| 612 | lookup_flags |= LOOKUP_REVAL; |
| 613 | goto retry; |
| 614 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | return error; |
| 616 | } |
| 617 | |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 618 | SYSCALL_DEFINE2(removexattr, const char __user *, pathname, |
| 619 | const char __user *, name) |
| 620 | { |
| 621 | return path_removexattr(pathname, name, LOOKUP_FOLLOW); |
| 622 | } |
| 623 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 624 | SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, |
| 625 | const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | { |
Eric Biggers | 8cc4311 | 2014-10-12 11:59:58 -0500 | [diff] [blame] | 627 | return path_removexattr(pathname, name, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 628 | } |
| 629 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 630 | SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 632 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | int error = -EBADF; |
| 634 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 635 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | return error; |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 637 | audit_file(f.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 638 | error = mnt_want_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 639 | if (!error) { |
Al Viro | 9f45f5b | 2014-10-31 17:44:57 -0400 | [diff] [blame] | 640 | error = removexattr(f.file->f_path.dentry, name); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 641 | mnt_drop_write_file(f.file); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 642 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 643 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | return error; |
| 645 | } |
| 646 | |
| 647 | |
| 648 | static const char * |
| 649 | strcmp_prefix(const char *a, const char *a_prefix) |
| 650 | { |
| 651 | while (*a_prefix && *a == *a_prefix) { |
| 652 | a++; |
| 653 | a_prefix++; |
| 654 | } |
| 655 | return *a_prefix ? NULL : a; |
| 656 | } |
| 657 | |
| 658 | /* |
| 659 | * In order to implement different sets of xattr operations for each xattr |
| 660 | * prefix with the generic xattr API, a filesystem should create a |
| 661 | * null-terminated array of struct xattr_handler (one for each prefix) and |
| 662 | * hang a pointer to it off of the s_xattr field of the superblock. |
| 663 | * |
| 664 | * The generic_fooxattr() functions will use this list to dispatch xattr |
| 665 | * operations to the correct xattr_handler. |
| 666 | */ |
| 667 | #define for_each_xattr_handler(handlers, handler) \ |
| 668 | for ((handler) = *(handlers)++; \ |
| 669 | (handler) != NULL; \ |
| 670 | (handler) = *(handlers)++) |
| 671 | |
| 672 | /* |
| 673 | * Find the xattr_handler with the matching prefix. |
| 674 | */ |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 675 | static const struct xattr_handler * |
| 676 | xattr_resolve_name(const struct xattr_handler **handlers, const char **name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 678 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | |
| 680 | if (!*name) |
| 681 | return NULL; |
| 682 | |
| 683 | for_each_xattr_handler(handlers, handler) { |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 684 | const char *n; |
| 685 | |
| 686 | n = strcmp_prefix(*name, xattr_prefix(handler)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | if (n) { |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 688 | if (!handler->prefix ^ !*n) { |
| 689 | if (*n) |
| 690 | continue; |
| 691 | return ERR_PTR(-EINVAL); |
| 692 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | *name = n; |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 694 | return handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | } |
| 696 | } |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 697 | return ERR_PTR(-EOPNOTSUPP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | } |
| 699 | |
| 700 | /* |
| 701 | * Find the handler for the prefix and dispatch its get() operation. |
| 702 | */ |
| 703 | ssize_t |
| 704 | generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size) |
| 705 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 706 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 707 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 708 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 709 | if (IS_ERR(handler)) |
| 710 | return PTR_ERR(handler); |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 711 | return handler->get(handler, dentry, name, buffer, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | } |
| 713 | |
| 714 | /* |
| 715 | * Combine the results of the list() operation from every xattr_handler in the |
| 716 | * list. |
| 717 | */ |
| 718 | ssize_t |
| 719 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) |
| 720 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 721 | const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | unsigned int size = 0; |
| 723 | |
| 724 | if (!buffer) { |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 725 | for_each_xattr_handler(handlers, handler) { |
Andreas Gruenbacher | c4803c4 | 2015-12-02 14:44:41 +0100 | [diff] [blame^] | 726 | if (!handler->list) |
| 727 | continue; |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 728 | size += handler->list(handler, dentry, NULL, 0, |
| 729 | NULL, 0); |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 730 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | } else { |
| 732 | char *buf = buffer; |
| 733 | |
| 734 | for_each_xattr_handler(handlers, handler) { |
Andreas Gruenbacher | c4803c4 | 2015-12-02 14:44:41 +0100 | [diff] [blame^] | 735 | if (!handler->list) |
| 736 | continue; |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 737 | size = handler->list(handler, dentry, buf, buffer_size, |
| 738 | NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | if (size > buffer_size) |
| 740 | return -ERANGE; |
| 741 | buf += size; |
| 742 | buffer_size -= size; |
| 743 | } |
| 744 | size = buf - buffer; |
| 745 | } |
| 746 | return size; |
| 747 | } |
| 748 | |
| 749 | /* |
| 750 | * Find the handler for the prefix and dispatch its set() operation. |
| 751 | */ |
| 752 | int |
| 753 | generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) |
| 754 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 755 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | |
| 757 | if (size == 0) |
| 758 | value = ""; /* empty EA, do not remove */ |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 759 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 760 | if (IS_ERR(handler)) |
| 761 | return PTR_ERR(handler); |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 762 | return handler->set(handler, dentry, name, value, size, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | } |
| 764 | |
| 765 | /* |
| 766 | * Find the handler for the prefix and dispatch its set() operation to remove |
| 767 | * any associated extended attribute. |
| 768 | */ |
| 769 | int |
| 770 | generic_removexattr(struct dentry *dentry, const char *name) |
| 771 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 772 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 774 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 775 | if (IS_ERR(handler)) |
| 776 | return PTR_ERR(handler); |
Andreas Gruenbacher | d9a82a0 | 2015-10-04 19:18:51 +0200 | [diff] [blame] | 777 | return handler->set(handler, dentry, name, NULL, 0, XATTR_REPLACE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | } |
| 779 | |
| 780 | EXPORT_SYMBOL(generic_getxattr); |
| 781 | EXPORT_SYMBOL(generic_listxattr); |
| 782 | EXPORT_SYMBOL(generic_setxattr); |
| 783 | EXPORT_SYMBOL(generic_removexattr); |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 784 | |
Andreas Gruenbacher | e409de9 | 2015-10-04 19:18:52 +0200 | [diff] [blame] | 785 | /** |
| 786 | * xattr_full_name - Compute full attribute name from suffix |
| 787 | * |
| 788 | * @handler: handler of the xattr_handler operation |
| 789 | * @name: name passed to the xattr_handler operation |
| 790 | * |
| 791 | * The get and set xattr handler operations are called with the remainder of |
| 792 | * the attribute name after skipping the handler's prefix: for example, "foo" |
| 793 | * is passed to the get operation of a handler with prefix "user." to get |
| 794 | * attribute "user.foo". The full name is still "there" in the name though. |
| 795 | * |
| 796 | * Note: the list xattr handler operation when called from the vfs is passed a |
| 797 | * NULL name; some file systems use this operation internally, with varying |
| 798 | * semantics. |
| 799 | */ |
| 800 | const char *xattr_full_name(const struct xattr_handler *handler, |
| 801 | const char *name) |
| 802 | { |
Andreas Gruenbacher | 98e9cb5 | 2015-12-02 14:44:36 +0100 | [diff] [blame] | 803 | size_t prefix_len = strlen(xattr_prefix(handler)); |
Andreas Gruenbacher | e409de9 | 2015-10-04 19:18:52 +0200 | [diff] [blame] | 804 | |
| 805 | return name - prefix_len; |
| 806 | } |
| 807 | EXPORT_SYMBOL(xattr_full_name); |
| 808 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 809 | /* |
| 810 | * Allocate new xattr and copy in the value; but leave the name to callers. |
| 811 | */ |
| 812 | struct simple_xattr *simple_xattr_alloc(const void *value, size_t size) |
| 813 | { |
| 814 | struct simple_xattr *new_xattr; |
| 815 | size_t len; |
| 816 | |
| 817 | /* wrap around? */ |
| 818 | len = sizeof(*new_xattr) + size; |
Hugh Dickins | 4e66d44 | 2014-07-23 14:00:17 -0700 | [diff] [blame] | 819 | if (len < sizeof(*new_xattr)) |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 820 | return NULL; |
| 821 | |
| 822 | new_xattr = kmalloc(len, GFP_KERNEL); |
| 823 | if (!new_xattr) |
| 824 | return NULL; |
| 825 | |
| 826 | new_xattr->size = size; |
| 827 | memcpy(new_xattr->value, value, size); |
| 828 | return new_xattr; |
| 829 | } |
| 830 | |
| 831 | /* |
| 832 | * xattr GET operation for in-memory/pseudo filesystems |
| 833 | */ |
| 834 | int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, |
| 835 | void *buffer, size_t size) |
| 836 | { |
| 837 | struct simple_xattr *xattr; |
| 838 | int ret = -ENODATA; |
| 839 | |
| 840 | spin_lock(&xattrs->lock); |
| 841 | list_for_each_entry(xattr, &xattrs->head, list) { |
| 842 | if (strcmp(name, xattr->name)) |
| 843 | continue; |
| 844 | |
| 845 | ret = xattr->size; |
| 846 | if (buffer) { |
| 847 | if (size < xattr->size) |
| 848 | ret = -ERANGE; |
| 849 | else |
| 850 | memcpy(buffer, xattr->value, xattr->size); |
| 851 | } |
| 852 | break; |
| 853 | } |
| 854 | spin_unlock(&xattrs->lock); |
| 855 | return ret; |
| 856 | } |
| 857 | |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 858 | /** |
| 859 | * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems |
| 860 | * @xattrs: target simple_xattr list |
| 861 | * @name: name of the extended attribute |
| 862 | * @value: value of the xattr. If %NULL, will remove the attribute. |
| 863 | * @size: size of the new xattr |
| 864 | * @flags: %XATTR_{CREATE|REPLACE} |
| 865 | * |
| 866 | * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails |
| 867 | * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist; |
| 868 | * otherwise, fails with -ENODATA. |
| 869 | * |
| 870 | * Returns 0 on success, -errno on failure. |
| 871 | */ |
| 872 | int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, |
| 873 | const void *value, size_t size, int flags) |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 874 | { |
| 875 | struct simple_xattr *xattr; |
David Rientjes | 4338584 | 2012-10-17 20:41:15 -0700 | [diff] [blame] | 876 | struct simple_xattr *new_xattr = NULL; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 877 | int err = 0; |
| 878 | |
| 879 | /* value == NULL means remove */ |
| 880 | if (value) { |
| 881 | new_xattr = simple_xattr_alloc(value, size); |
| 882 | if (!new_xattr) |
| 883 | return -ENOMEM; |
| 884 | |
| 885 | new_xattr->name = kstrdup(name, GFP_KERNEL); |
| 886 | if (!new_xattr->name) { |
| 887 | kfree(new_xattr); |
| 888 | return -ENOMEM; |
| 889 | } |
| 890 | } |
| 891 | |
| 892 | spin_lock(&xattrs->lock); |
| 893 | list_for_each_entry(xattr, &xattrs->head, list) { |
| 894 | if (!strcmp(name, xattr->name)) { |
| 895 | if (flags & XATTR_CREATE) { |
| 896 | xattr = new_xattr; |
| 897 | err = -EEXIST; |
| 898 | } else if (new_xattr) { |
| 899 | list_replace(&xattr->list, &new_xattr->list); |
| 900 | } else { |
| 901 | list_del(&xattr->list); |
| 902 | } |
| 903 | goto out; |
| 904 | } |
| 905 | } |
| 906 | if (flags & XATTR_REPLACE) { |
| 907 | xattr = new_xattr; |
| 908 | err = -ENODATA; |
| 909 | } else { |
| 910 | list_add(&new_xattr->list, &xattrs->head); |
| 911 | xattr = NULL; |
| 912 | } |
| 913 | out: |
| 914 | spin_unlock(&xattrs->lock); |
| 915 | if (xattr) { |
| 916 | kfree(xattr->name); |
| 917 | kfree(xattr); |
| 918 | } |
| 919 | return err; |
| 920 | |
| 921 | } |
| 922 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 923 | static bool xattr_is_trusted(const char *name) |
| 924 | { |
| 925 | return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN); |
| 926 | } |
| 927 | |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 928 | static int xattr_list_one(char **buffer, ssize_t *remaining_size, |
| 929 | const char *name) |
| 930 | { |
| 931 | size_t len = strlen(name) + 1; |
| 932 | if (*buffer) { |
| 933 | if (*remaining_size < len) |
| 934 | return -ERANGE; |
| 935 | memcpy(*buffer, name, len); |
| 936 | *buffer += len; |
| 937 | } |
| 938 | *remaining_size -= len; |
| 939 | return 0; |
| 940 | } |
| 941 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 942 | /* |
| 943 | * xattr LIST operation for in-memory/pseudo filesystems |
| 944 | */ |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 945 | ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, |
| 946 | char *buffer, size_t size) |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 947 | { |
| 948 | bool trusted = capable(CAP_SYS_ADMIN); |
| 949 | struct simple_xattr *xattr; |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 950 | ssize_t remaining_size = size; |
| 951 | int err; |
| 952 | |
| 953 | #ifdef CONFIG_FS_POSIX_ACL |
| 954 | if (inode->i_acl) { |
| 955 | err = xattr_list_one(&buffer, &remaining_size, |
| 956 | XATTR_NAME_POSIX_ACL_ACCESS); |
| 957 | if (err) |
| 958 | return err; |
| 959 | } |
| 960 | if (inode->i_default_acl) { |
| 961 | err = xattr_list_one(&buffer, &remaining_size, |
| 962 | XATTR_NAME_POSIX_ACL_DEFAULT); |
| 963 | if (err) |
| 964 | return err; |
| 965 | } |
| 966 | #endif |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 967 | |
| 968 | spin_lock(&xattrs->lock); |
| 969 | list_for_each_entry(xattr, &xattrs->head, list) { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 970 | /* skip "trusted." attributes for unprivileged callers */ |
| 971 | if (!trusted && xattr_is_trusted(xattr->name)) |
| 972 | continue; |
| 973 | |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 974 | err = xattr_list_one(&buffer, &remaining_size, xattr->name); |
| 975 | if (err) |
| 976 | return err; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 977 | } |
| 978 | spin_unlock(&xattrs->lock); |
| 979 | |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 980 | return size - remaining_size; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 981 | } |
| 982 | |
Aristeu Rozanski | 4895768 | 2012-09-11 16:28:11 -0400 | [diff] [blame] | 983 | /* |
| 984 | * Adds an extended attribute to the list |
| 985 | */ |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 986 | void simple_xattr_list_add(struct simple_xattrs *xattrs, |
| 987 | struct simple_xattr *new_xattr) |
| 988 | { |
| 989 | spin_lock(&xattrs->lock); |
| 990 | list_add(&new_xattr->list, &xattrs->head); |
| 991 | spin_unlock(&xattrs->lock); |
| 992 | } |