[PATCH 04/38] vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled [ver #10]

David Howells
2018-07-27T17:31:55Z

Only the mount namespace code that implements mount(2) should be using the
MS_* flags. Suppress them inside the kernel unless uapi/linux/mount.h is
included.

Signed-off-by: David Howells <dhowells@redhat.com>
---

arch/arc/kernel/setup.c | 1 +
arch/arm/kernel/atags_parse.c | 1 +
arch/sh/kernel/setup.c | 1 +
arch/sparc/kernel/setup_32.c | 1 +
arch/sparc/kernel/setup_64.c | 1 +
arch/x86/kernel/setup.c | 1 +
drivers/base/devtmpfs.c | 1 +
fs/f2fs/super.c | 2 +
fs/pnode.c | 1 +
fs/super.c | 1 +
include/uapi/linux/fs.h | 56 ++++-------------------------------------
include/uapi/linux/mount.h | 54 ++++++++++++++++++++++++++++++++++++++++
init/do_mounts.c | 1 +
init/do_mounts_initrd.c | 1 +
security/apparmor/lsm.c | 1 +
security/apparmor/mount.c | 1 +
security/selinux/hooks.c | 1 +
security/tomoyo/mount.c | 1 +
18 files changed, 75 insertions(+), 52 deletions(-)

diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index b2cae79a25d7..714dc5c2baf1 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -19,6 +19,7 @@
#include <linux/of_fdt.h>
#include <linux/of.h>
#include <linux/cache.h>
+#include <uapi/linux/mount.h>
#include <asm/sections.h>
#include <asm/arcregs.h>
#include <asm/tlb.h>
diff --git a/arch/arm/kernel/atags_parse.c b/arch/arm/kernel/atags_parse.c
index c10a3e8ee998..a8a4333929f5 100644
--- a/arch/arm/kernel/atags_parse.c
+++ b/arch/arm/kernel/atags_parse.c
@@ -24,6 +24,7 @@
#include <linux/root_dev.h>
#include <linux/screen_info.h>
#include <linux/memblock.h>
+#include <uapi/linux/mount.h>

#include <asm/setup.h>
#include <asm/system_info.h>
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index c286cf5da6e7..2c0e0f37a318 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -32,6 +32,7 @@
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/uaccess.h>
+#include <uapi/linux/mount.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/elf.h>
diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c
index 13664c377196..7df3d704284c 100644
--- a/arch/sparc/kernel/setup_32.c
+++ b/arch/sparc/kernel/setup_32.c
@@ -34,6 +34,7 @@
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/start_kernel.h>
+#include <uapi/linux/mount.h>

#include <asm/io.h>
#include <asm/processor.h>
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index 7944b3ca216a..206bf81eedaf 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -33,6 +33,7 @@
#include <linux/module.h>
#include <linux/start_kernel.h>
#include <linux/bootmem.h>
+#include <uapi/linux/mount.h>

#include <asm/io.h>
#include <asm/processor.h>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 2f86d883dd95..3413f53e0a35 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -51,6 +51,7 @@
#include <linux/kvm_para.h>
#include <linux/dma-contiguous.h>
#include <xen/xen.h>
+#include <uapi/linux/mount.h>

#include <linux/errno.h>
#include <linux/kernel.h>
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 9c0126ad7de1..1b87a1e03b45 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -25,6 +25,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kthread.h>
+#include <uapi/linux/mount.h>
#include "base.h"

static struct task_struct *thread;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 1c56a9f2598d..3dbf69209fe2 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1454,7 +1454,7 @@ static int f2fs_remount(struct super_block *sb, int *flags,
err = dquot_suspend(sb, -1);
if (err < 0)
goto restore_opts;
- } else if (f2fs_readonly(sb) && !(*flags & MS_RDONLY)) {
+ } else if (f2fs_readonly(sb) && !(*flags & SB_RDONLY)) {
/* dquot_resume needs RW */
sb->s_flags &= ~SB_RDONLY;
if (sb_any_quota_suspended(sb)) {
diff --git a/fs/pnode.c b/fs/pnode.c
index 53d411a371ce..1100e810d855 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -10,6 +10,7 @@
#include <linux/mount.h>
#include <linux/fs.h>
#include <linux/nsproxy.h>
+#include <uapi/linux/mount.h>
#include "internal.h"
#include "pnode.h"

diff --git a/fs/super.c b/fs/super.c
index c9333d317b5f..c9d208b7999e 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -35,6 +35,7 @@
#include <linux/fsnotify.h>
#include <linux/lockdep.h>
#include <linux/user_namespace.h>
+#include <uapi/linux/mount.h>
#include "internal.h"

static int thaw_super_locked(struct super_block *sb);
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 73e01918f996..1c982eb44ff4 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -14,6 +14,11 @@
#include <linux/ioctl.h>
#include <linux/types.h>

+/* Use of MS_* flags within the kernel is restricted to core mount(2) code. */
+#if !defined(__KERNEL__)
+#include <linux/mount.h>
+#endif
+
/*
* It's silly to have NR_OPEN bigger than NR_FILE, but you can change
* the file limit at runtime and only root can increase the per-process
@@ -101,57 +106,6 @@ struct inodes_stat_t {

#define NR_FILE 8192 /* this can well be larger on a larger system */

-
-/*
- * These are the fs-independent mount-flags: up to 32 flags are supported
- */
-#define MS_RDONLY 1 /* Mount read-only */
-#define MS_NOSUID 2 /* Ignore suid and sgid bits */
-#define MS_NODEV 4 /* Disallow access to device special files */
-#define MS_NOEXEC 8 /* Disallow program execution */
-#define MS_SYNCHRONOUS 16 /* Writes are synced at once */
-#define MS_REMOUNT 32 /* Alter flags of a mounted FS */
-#define MS_MANDLOCK 64 /* Allow mandatory locks on an FS */
-#define MS_DIRSYNC 128 /* Directory modifications are synchronous */
-#define MS_NOATIME 1024 /* Do not update access times. */
-#define MS_NODIRATIME 2048 /* Do not update directory access times */
-#define MS_BIND 4096
-#define MS_MOVE 8192
-#define MS_REC 16384
-#define MS_VERBOSE 32768 /* War is peace. Verbosity is silence.
- MS_VERBOSE is deprecated. */
-#define MS_SILENT 32768
-#define MS_POSIXACL (1<<16) /* VFS does not apply the umask */
-#define MS_UNBINDABLE (1<<17) /* change to unbindable */
-#define MS_PRIVATE (1<<18) /* change to private */
-#define MS_SLAVE (1<<19) /* change to slave */
-#define MS_SHARED (1<<20) /* change to shared */
-#define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */
-#define MS_KERNMOUNT (1<<22) /* this is a kern_mount call */
-#define MS_I_VERSION (1<<23) /* Update inode I_version field */
-#define MS_STRICTATIME (1<<24) /* Always perform atime updates */
-#define MS_LAZYTIME (1<<25) /* Update the on-disk [acm]times lazily */
-
-/* These sb flags are internal to the kernel */
-#define MS_SUBMOUNT (1<<26)
-#define MS_NOREMOTELOCK (1<<27)
-#define MS_NOSEC (1<<28)
-#define MS_BORN (1<<29)
-#define MS_ACTIVE (1<<30)
-#define MS_NOUSER (1<<31)
-
-/*
- * Superblock flags that can be altered by MS_REMOUNT
- */
-#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
- MS_LAZYTIME)
-
-/*
- * Old magic mount flag and mask
- */
-#define MS_MGC_VAL 0xC0ED0000
-#define MS_MGC_MSK 0xffff0000
-
/*
* Structure for FS_IOC_FSGETXATTR[A] and FS_IOC_FSSETXATTR.
*/
diff --git a/include/uapi/linux/mount.h b/include/uapi/linux/mount.h
index 89adf0d731ab..3634e065836c 100644
--- a/include/uapi/linux/mount.h
+++ b/include/uapi/linux/mount.h
@@ -1,6 +1,60 @@
#ifndef _UAPI_LINUX_MOUNT_H
#define _UAPI_LINUX_MOUNT_H

+/*
+ * These are the fs-independent mount-flags: up to 32 flags are supported
+ *
+ * Usage of these is restricted within the kernel to core mount(2) code and
+ * callers of sys_mount() only. Filesystems should be using the SB_*
+ * equivalent instead.
+ */
+#define MS_RDONLY 1 /* Mount read-only */
+#define MS_NOSUID 2 /* Ignore suid and sgid bits */
+#define MS_NODEV 4 /* Disallow access to device special files */
+#define MS_NOEXEC 8 /* Disallow program execution */
+#define MS_SYNCHRONOUS 16 /* Writes are synced at once */
+#define MS_REMOUNT 32 /* Alter flags of a mounted FS */
+#define MS_MANDLOCK 64 /* Allow mandatory locks on an FS */
+#define MS_DIRSYNC 128 /* Directory modifications are synchronous */
+#define MS_NOATIME 1024 /* Do not update access times. */
+#define MS_NODIRATIME 2048 /* Do not update directory access times */
+#define MS_BIND 4096
+#define MS_MOVE 8192
+#define MS_REC 16384
+#define MS_VERBOSE 32768 /* War is peace. Verbosity is silence.
+ MS_VERBOSE is deprecated. */
+#define MS_SILENT 32768
+#define MS_POSIXACL (1<<16) /* VFS does not apply the umask */
+#define MS_UNBINDABLE (1<<17) /* change to unbindable */
+#define MS_PRIVATE (1<<18) /* change to private */
+#define MS_SLAVE (1<<19) /* change to slave */
+#define MS_SHARED (1<<20) /* change to shared */
+#define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */
+#define MS_KERNMOUNT (1<<22) /* this is a kern_mount call */
+#define MS_I_VERSION (1<<23) /* Update inode I_version field */
+#define MS_STRICTATIME (1<<24) /* Always perform atime updates */
+#define MS_LAZYTIME (1<<25) /* Update the on-disk [acm]times lazily */
+
+/* These sb flags are internal to the kernel */
+#define MS_SUBMOUNT (1<<26)
+#define MS_NOREMOTELOCK (1<<27)
+#define MS_NOSEC (1<<28)
+#define MS_BORN (1<<29)
+#define MS_ACTIVE (1<<30)
+#define MS_NOUSER (1<<31)
+
+/*
+ * Superblock flags that can be altered by MS_REMOUNT
+ */
+#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
+ MS_LAZYTIME)
+
+/*
+ * Old magic mount flag and mask
+ */
+#define MS_MGC_VAL 0xC0ED0000
+#define MS_MGC_MSK 0xffff0000
+
/*
* open_tree() flags.
*/
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 7e26be00c444..d4fc2a5afdb6 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -32,6 +32,7 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
+#include <uapi/linux/mount.h>

#include "do_mounts.h"

diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index 5a91aefa7305..65de0412f80f 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -18,6 +18,7 @@
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kmod.h>
+#include <uapi/linux/mount.h>

#include "do_mounts.h"

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index bc3e209d2bd4..84e644ce3583 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -24,6 +24,7 @@
#include <linux/audit.h>
#include <linux/user_namespace.h>
#include <net/sock.h>
+#include <uapi/linux/mount.h>

#include "include/apparmor.h"
#include "include/apparmorfs.h"
diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c
index c1da22482bfb..8c3787399356 100644
--- a/security/apparmor/mount.c
+++ b/security/apparmor/mount.c
@@ -15,6 +15,7 @@
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/namei.h>
+#include <uapi/linux/mount.h>

#include "include/apparmor.h"
#include "include/audit.h"
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f5e5c8a087ae..ef0428311a5c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -88,6 +88,7 @@
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/bpf.h>
+#include <uapi/linux/mount.h>

#include "avc.h"
#include "objsec.h"
diff --git a/security/tomoyo/mount.c b/security/tomoyo/mount.c
index 807fd91dbb54..7dc7f59b7dde 100644
--- a/security/tomoyo/mount.c
+++ b/security/tomoyo/mount.c
@@ -6,6 +6,7 @@
*/

#include <linux/slab.h>
+#include <uapi/linux/mount.h>
#include "common.h"

/* String table for special mount operations. */