if (!S_ISBLK(inode->i_mode))
goto fail;
error = -EACCES;
- if (path.mnt->mnt_flags & MNT_NODEV)
+ if (!may_open_dev(&path))
goto fail;
error = -ENOMEM;
bdev = bd_acquire(inode);
struct dentry *root;
info->sb = sb;
- /* Userspace would break if executables appear on sysfs */
- sb->s_iflags |= SB_I_NOEXEC;
+ /* Userspace would break if executables or devices appear on sysfs */
+ sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = magic;
}
EXPORT_SYMBOL(vfs_create);
+bool may_open_dev(const struct path *path)
+{
+ return !(path->mnt->mnt_flags & MNT_NODEV) &&
+ !(path->mnt->mnt_sb->s_iflags & SB_I_NODEV);
+}
+
static int may_open(struct path *path, int acc_mode, int flag)
{
struct dentry *dentry = path->dentry;
break;
case S_IFBLK:
case S_IFCHR:
- if (path->mnt->mnt_flags & MNT_NODEV)
+ if (!may_open_dev(path))
return -EACCES;
/*FALLTHRU*/
case S_IFIFO:
if (!proc_parse_options(data, ns))
return -EINVAL;
- /* User space would break if executables appear on proc */
- s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC;
+ /* User space would break if executables or devices appear on proc */
+ s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
/* sb->s_iflags */
#define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */
#define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */
+#define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */
/* sb->s_iflags to limit user namespace mounts */
#define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */
*/
extern void inode_init_owner(struct inode *inode, const struct inode *dir,
umode_t mode);
+extern bool may_open_dev(const struct path *path);
/*
* VFS FS_IOC_FIEMAP helper definitions.
*/
struct inode *inode;
struct ipc_namespace *ns = sb->s_fs_info;
- sb->s_iflags |= SB_I_NOEXEC;
+ sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = MQUEUE_MAGIC;