LSM blob has been involved for superblock's security struct. So fix the
remaining direct access to sb->s_security by using the LSM blob
mechanism.

Fixes: 08abe46b2cfc ("selinux: fall back to SECURITY_FS_USE_GENFS if no xattr support")
Fixes: 69c4a42d72eb ("lsm,selinux: add new hook to compare new mount to an existing mount")
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
---
 security/selinux/hooks.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5b6895e4fc29..a0243bae8423 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -479,7 +479,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
 
 static int sb_check_xattr_support(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	struct dentry *root = sb->s_root;
 	struct inode *root_inode = d_backing_inode(root);
 	u32 sid;
@@ -2647,7 +2647,7 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
 {
 	struct selinux_mnt_opts *opts = mnt_opts;
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	u32 sid;
 	int rc;
 
-- 
2.17.1

On 1/24/2022 11:11 PM, GONG, Ruiqi wrote:
> LSM blob has been involved for superblock's security struct. So fix the
> remaining direct access to sb->s_security by using the LSM blob
> mechanism.
>
> Fixes: 08abe46b2cfc ("selinux: fall back to SECURITY_FS_USE_GENFS if no xattr support")
> Fixes: 69c4a42d72eb ("lsm,selinux: add new hook to compare new mount to an existing mount")
> Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>

Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>

This is pretty important.

> ---
>   security/selinux/hooks.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 5b6895e4fc29..a0243bae8423 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -479,7 +479,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
>   
>   static int sb_check_xattr_support(struct super_block *sb)
>   {
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>   	struct dentry *root = sb->s_root;
>   	struct inode *root_inode = d_backing_inode(root);
>   	u32 sid;
> @@ -2647,7 +2647,7 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
>   static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
>   {
>   	struct selinux_mnt_opts *opts = mnt_opts;
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>   	u32 sid;
>   	int rc;
>   

On Tue, Jan 25, 2022 at 2:12 AM GONG, Ruiqi <gongruiqi1@huawei.com> wrote:
>
> LSM blob has been involved for superblock's security struct. So fix the
> remaining direct access to sb->s_security by using the LSM blob
> mechanism.
>
> Fixes: 08abe46b2cfc ("selinux: fall back to SECURITY_FS_USE_GENFS if no xattr support")
> Fixes: 69c4a42d72eb ("lsm,selinux: add new hook to compare new mount to an existing mount")
> Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
> ---
>  security/selinux/hooks.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Thanks for the patch!  I just merged this into selinux/next.

-- 
paul-moore.com