lsm: constify 'sb' parameter in security_sb_remount()

PATCH In review Khadija Kamran 3 participants 3 messages Aug 23, 2023 – Sep 13, 2023

Subsystems (3)

SELinux security module Security (LSM) Landlock security module

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Khadija Kamran

author

2023-08-23 08:57 UTC #0 lore raw

PATCH 1/1 lsm: constify 'sb' parameter in security_sb_remount()

The "sb_remount" hook has implementations registered in SELinux and Landlock. Looking at the function implementations we observe that the "sb" parameter is not changing.

Mark the "sb" parameter of LSM hook security_sb_remount() as "const" since it will not be changing in the LSM hook.

Signed-off-by Khadija Kamran <[email protected]>

---
 include/linux/lsm_hook_defs.h | 2 +-
 include/linux/security.h      | 2 +-
 security/landlock/fs.c        | 2 +-
 security/security.c           | 2 +-
 security/selinux/hooks.c      | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

include/linux/lsm_hook_defs.h +1 -1

index 6bb55e61e8e8..dca689c9ac04 100644
@@ -64,7 +64,7 @@ LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb)
 LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
 LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
 LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
-LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
+LSM_HOOK(int, 0, sb_remount, const struct super_block *sb, void *mnt_opts)
 LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
 LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
 LSM_HOOK(int, 0, sb_statfs, struct dentry *dentry)

include/linux/security.h +1 -1

index e2734e9e44d5..ce08ed7d5437 100644
@@ -301,7 +301,7 @@ void security_sb_free(struct super_block *sb);
 void security_free_mnt_opts(void **mnt_opts);
 int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
 int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
-int security_sb_remount(struct super_block *sb, void *mnt_opts);
+int security_sb_remount(const struct super_block *sb, void *mnt_opts);
 int security_sb_kern_mount(struct super_block *sb);
 int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);

security/landlock/fs.c +1 -1

index 1c0c198f6fdb..fabe324922ec 100644
@@ -1074,7 +1074,7 @@ static int hook_sb_umount(struct vfsmount *const mnt, const int flags)
 	return -EPERM;
 }
 
-static int hook_sb_remount(struct super_block *const sb, void *const mnt_opts)
+static int hook_sb_remount(const struct super_block *const sb, void *const mnt_opts)
 {
 	if (!landlock_get_current_domain())
 		return 0;

security/security.c +1 -1

index d5ff7ff45b77..acc8a92ba857 100644
@@ -1289,7 +1289,7 @@ EXPORT_SYMBOL(security_sb_mnt_opts_compat);
  *
  * Return: Returns 0 if permission is granted.
  */
-int security_sb_remount(struct super_block *sb,
+int security_sb_remount(const struct super_block *sb,
 			void *mnt_opts)
 {
 	return call_int_hook(sb_remount, 0, sb, mnt_opts);

security/selinux/hooks.c +1 -1

index 79b4890e9936..e4de42150b87 100644
@@ -2628,7 +2628,7 @@ static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
 	return 0;
 }
 
-static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
+static int selinux_sb_remount(const struct super_block *sb, void *mnt_opts)
 {
 	struct selinux_mnt_opts *opts = mnt_opts;
 	struct superblock_security_struct *sbsec = selinux_superblock(sb);

Signature · 1 line

2.34.1

Mickaël Salaün

maintainer

2023-08-23 12:44 UTC #1 lore raw

Hi Khadija,

Quoted 21 lines · Khadija Kamran

The "sb_remount" hook has implementations registered in SELinux and Landlock. Looking at the function implementations we observe that the "sb" parameter is not changing.
Mark the "sb" parameter of LSM hook security_sb_remount() as "const" since it will not be changing in the LSM hook.
Signed-off-by Khadija Kamran <[email protected]>
---
 include/linux/lsm_hook_defs.h | 2 +-
 include/linux/security.h      | 2 +-
 security/landlock/fs.c        | 2 +-
 security/security.c           | 2 +-
 security/selinux/hooks.c      | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)
security/landlock/fs.c +0 -0
index 1c0c198f6fdb..fabe324922ec 100644

security/landlock/fs.c static int hook_sb_umount(struct vfsmount *const mnt, const int flags) · line 1077

Quoted 5 lines

security/landlock/fs.c +1 -1

@@ -1074,7 +1074,7 @@ static int hook_sb_umount(struct vfsmount *const mnt, const int flags)
 	return -EPERM;
 }
 
-static int hook_sb_remount(struct super_block *const sb, void *const mnt_opts)
+static int hook_sb_remount(const struct super_block *const sb, void *const mnt_opts)

Please format with clang-format -i security/landlock/*.[ch]

Quoted 3 lines

security/landlock/fs.c +0 -0

 {
 	if (!landlock_get_current_domain())
 		return 0;

Paul Moore

maintainer

2023-09-13 22:05 UTC #2 lore raw

Quoted 28 lines · Mickaël Salaün

Hi Khadija,
Quoted 24 lines · Khadija Kamran
The "sb_remount" hook has implementations registered in SELinux and Landlock. Looking at the function implementations we observe that the "sb" parameter is not changing.
Mark the "sb" parameter of LSM hook security_sb_remount() as "const" since it will not be changing in the LSM hook.
Signed-off-by Khadija Kamran <[email protected]>
---
 include/linux/lsm_hook_defs.h | 2 +-
 include/linux/security.h      | 2 +-
 security/landlock/fs.c        | 2 +-
 security/security.c           | 2 +-
 security/selinux/hooks.c      | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)
security/landlock/fs.c +0 -0
index 1c0c198f6fdb..fabe324922ec 100644
@@ -1074,7 +1074,7 @@ static int hook_sb_umount(struct vfsmount *const mnt, const int flags)
      return -EPERM;
 }
 

Quoted 4 lines

security/landlock/fs.c static int hook_sb_umount(struct vfsmount *const mnt, const int flags) · line 1077
Quoted 2 lines
security/landlock/fs.c +1 -1
-static int hook_sb_remount(struct super_block *const sb, void *const mnt_opts)
+static int hook_sb_remount(const struct super_block *const sb, void *const mnt_opts)
Please format with clang-format -i security/landlock/*.[ch]

Hi Khadija, can you please format the security/landlock/fs.c change as requested by Mickaël?

You can find information on running clang-format on the Linux kernel at the link below:
* https://www.kernel.org/doc/html/next/process/clang-format.html

Signature · 1 line

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