/* no ->get_acl() calls in RCU mode... */
if (is_uncached_acl(acl))
return -ECHILD;
- return posix_acl_permission(inode, acl, mask & ~MAY_NOT_BLOCK);
+ return posix_acl_permission(inode, acl, mask);
}
acl = get_acl(inode, ACL_TYPE_ACCESS);
}
/*
- * This does the basic permission checking
+ * This does the basic UNIX permission checking.
+ *
+ * Note that the POSIX ACL check cares about the MAY_NOT_BLOCK bit,
+ * for RCU walking.
*/
static int acl_permission_check(struct inode *inode, int mask)
{
unsigned int mode = inode->i_mode;
- if (likely(uid_eq(current_fsuid(), inode->i_uid)))
+ /* Are we the owner? If so, ACL's don't matter */
+ if (likely(uid_eq(current_fsuid(), inode->i_uid))) {
+ mask &= 7;
mode >>= 6;
- else {
- if (IS_POSIXACL(inode) && (mode & S_IRWXG)) {
- int error = check_acl(inode, mask);
- if (error != -EAGAIN)
- return error;
- }
+ return (mask & ~mode) ? -EACCES : 0;
+ }
- if (in_group_p(inode->i_gid))
- mode >>= 3;
+ /* Do we have ACL's? */
+ if (IS_POSIXACL(inode) && (mode & S_IRWXG)) {
+ int error = check_acl(inode, mask);
+ if (error != -EAGAIN)
+ return error;
}
+ /* Only RWX matters for group/other mode bits */
+ mask &= 7;
+
/*
- * If the DACs are ok we don't need any capability check.
+ * Are the group permissions different from
+ * the other permissions in the bits we care
+ * about? Need to check group ownership if so.
*/
- if ((mask & ~mode & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
- return 0;
- return -EACCES;
+ if (mask & (mode ^ (mode >> 3))) {
+ if (in_group_p(inode->i_gid))
+ mode >>= 3;
+ }
+
+ /* Bits in 'mode' clear that we require? */
+ return (mask & ~mode) ? -EACCES : 0;
}
/**
* generic_permission - check for access rights on a Posix-like filesystem
* @inode: inode to check access rights for
- * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC, ...)
+ * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC,
+ * %MAY_NOT_BLOCK ...)
*
* Used to check for read/write/execute permissions on a file.
* We use "fsuid" for this, letting us set arbitrary permissions
*
* Returns 0 if successful, -ve on error.
*/
-static int may_linkat(struct path *link)
+int may_linkat(struct path *link)
{
struct inode *inode = link->dentry->d_inode;
case S_IFDIR:
if (acc_mode & MAY_WRITE)
return -EISDIR;
+ if (acc_mode & MAY_EXEC)
+ return -EACCES;
break;
case S_IFBLK:
case S_IFCHR:
if (!may_open_dev(path))
return -EACCES;
- /*FALLTHRU*/
+ fallthrough;
case S_IFIFO:
case S_IFSOCK:
+ if (acc_mode & MAY_EXEC)
+ return -EACCES;
flag &= ~O_TRUNC;
break;
+ case S_IFREG:
+ if ((acc_mode & MAY_EXEC) && path_noexec(path))
+ return -EACCES;
+ break;
}
error = inode_permission(inode, MAY_OPEN | acc_mode);
int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
{
+ bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV;
int error = may_create(dir, dentry);
if (error)
return error;
- if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
+ if ((S_ISCHR(mode) || S_ISBLK(mode)) && !is_whiteout &&
+ !capable(CAP_MKNOD))
return -EPERM;
if (!dir->i_op->mknod)
}
}
-long do_mknodat(int dfd, const char __user *filename, umode_t mode,
+static long do_mknodat(int dfd, const char __user *filename, umode_t mode,
unsigned int dev)
{
struct dentry *dentry;
}
EXPORT_SYMBOL(vfs_mkdir);
-long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
+static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
{
struct dentry *dentry;
struct path path;
}
EXPORT_SYMBOL(vfs_rmdir);
-long do_rmdir(int dfd, const char __user *pathname)
+long do_rmdir(int dfd, struct filename *name)
{
int error = 0;
- struct filename *name;
struct dentry *dentry;
struct path path;
struct qstr last;
int type;
unsigned int lookup_flags = 0;
retry:
- name = filename_parentat(dfd, getname(pathname), lookup_flags,
+ name = filename_parentat(dfd, name, lookup_flags,
&path, &last, &type);
if (IS_ERR(name))
return PTR_ERR(name);
mnt_drop_write(path.mnt);
exit1:
path_put(&path);
- putname(name);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
+ putname(name);
return error;
}
SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
{
- return do_rmdir(AT_FDCWD, pathname);
+ return do_rmdir(AT_FDCWD, getname(pathname));
}
/**
return -EINVAL;
if (flag & AT_REMOVEDIR)
- return do_rmdir(dfd, pathname);
-
+ return do_rmdir(dfd, getname(pathname));
return do_unlinkat(dfd, getname(pathname));
}
}
EXPORT_SYMBOL(vfs_symlink);
-long do_symlinkat(const char __user *oldname, int newdfd,
+static long do_symlinkat(const char __user *oldname, int newdfd,
const char __user *newname)
{
int error;
* with linux 2.0, and to avoid hard-linking to directories
* and other special files. --ADM
*/
-int do_linkat(int olddfd, const char __user *oldname, int newdfd,
+static int do_linkat(int olddfd, const char __user *oldname, int newdfd,
const char __user *newname, int flags)
{
struct dentry *new_dentry;
(flags & RENAME_EXCHANGE))
return -EINVAL;
- if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD))
- return -EPERM;
-
if (flags & RENAME_EXCHANGE)
target_flags = 0;
return do_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
}
-int vfs_whiteout(struct inode *dir, struct dentry *dentry)
-{
- int error = may_create(dir, dentry);
- if (error)
- return error;
-
- if (!dir->i_op->mknod)
- return -EPERM;
-
- return dir->i_op->mknod(dir, dentry,
- S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV);
-}
-EXPORT_SYMBOL(vfs_whiteout);
-
int readlink_copy(char __user *buffer, int buflen, const char *link)
{
int len = PTR_ERR(link);
projects / linux-2.6-microblaze.git / blobdiff