RE: [PATCH 3/5] ->getprocattr(): attribute name is const char *, TYVM...

[Schaufler, Casey]

> -----Original Message-----
> From: Al Viro <viro@xxxxxxxxxxxxxxxx> On Behalf Of Al Viro
> Sent: Wednesday, August 17, 2022 7:59 PM
> To: linux-fsdevel@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH 3/5] ->getprocattr(): attribute name is const char *, TYVM...
> 
> cast of ->d_name.name to char * is completely wrong - nothing is
> allowed to modify its contents.
> 
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Could we please have the LSM list included when making changes in
the security sub-system?

Thank you.

> ---
>  fs/proc/base.c                | 2 +-
>  include/linux/lsm_hook_defs.h | 2 +-
>  include/linux/security.h      | 4 ++--
>  security/apparmor/lsm.c       | 2 +-
>  security/security.c           | 4 ++--
>  security/selinux/hooks.c      | 2 +-
>  security/smack/smack_lsm.c    | 2 +-
>  7 files changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 93f7e3d971e4..e347b8ce140c 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2728,7 +2728,7 @@ static ssize_t proc_pid_attr_read(struct file * file,
> char __user * buf,
>  		return -ESRCH;
> 
>  	length = security_getprocattr(task, PROC_I(inode)->op.lsm,
> -				      (char*)file->f_path.dentry-
> >d_name.name,
> +				      file->f_path.dentry->d_name.name,
>  				      &p);
>  	put_task_struct(task);
>  	if (length > 0)
> diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
> index 806448173033..03360d27bedf 100644
> --- a/include/linux/lsm_hook_defs.h
> +++ b/include/linux/lsm_hook_defs.h
> @@ -253,7 +253,7 @@ LSM_HOOK(int, 0, sem_semop, struct kern_ipc_perm
> *perm, struct sembuf *sops,
>  LSM_HOOK(int, 0, netlink_send, struct sock *sk, struct sk_buff *skb)
>  LSM_HOOK(void, LSM_RET_VOID, d_instantiate, struct dentry *dentry,
>  	 struct inode *inode)
> -LSM_HOOK(int, -EINVAL, getprocattr, struct task_struct *p, char *name,
> +LSM_HOOK(int, -EINVAL, getprocattr, struct task_struct *p, const char
> *name,
>  	 char **value)
>  LSM_HOOK(int, -EINVAL, setprocattr, const char *name, void *value, size_t
> size)
>  LSM_HOOK(int, 0, ismaclabel, const char *name)
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 1bc362cb413f..93488c01d9bd 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -461,7 +461,7 @@ int security_sem_semctl(struct kern_ipc_perm *sma,
> int cmd);
>  int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
>  			unsigned nsops, int alter);
>  void security_d_instantiate(struct dentry *dentry, struct inode *inode);
> -int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
> +int security_getprocattr(struct task_struct *p, const char *lsm, const char
> *name,
>  			 char **value);
>  int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size);
> @@ -1301,7 +1301,7 @@ static inline void security_d_instantiate(struct
> dentry *dentry,
>  { }
> 
>  static inline int security_getprocattr(struct task_struct *p, const char *lsm,
> -				       char *name, char **value)
> +				       const char *name, char **value)
>  {
>  	return -EINVAL;
>  }
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index e29cade7b662..f56070270c69 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -614,7 +614,7 @@ static int apparmor_sb_pivotroot(const struct path
> *old_path,
>  	return error;
>  }
> 
> -static int apparmor_getprocattr(struct task_struct *task, char *name,
> +static int apparmor_getprocattr(struct task_struct *task, const char *name,
>  				char **value)
>  {
>  	int error = -ENOENT;
> diff --git a/security/security.c b/security/security.c
> index 14d30fec8a00..d8227531e2fd 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2057,8 +2057,8 @@ void security_d_instantiate(struct dentry *dentry,
> struct inode *inode)
>  }
>  EXPORT_SYMBOL(security_d_instantiate);
> 
> -int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
> -				char **value)
> +int security_getprocattr(struct task_struct *p, const char *lsm,
> +			 const char *name, char **value)
>  {
>  	struct security_hook_list *hp;
> 
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 79573504783b..c8168d19fb96 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6327,7 +6327,7 @@ static void selinux_d_instantiate(struct dentry
> *dentry, struct inode *inode)
>  }
> 
>  static int selinux_getprocattr(struct task_struct *p,
> -			       char *name, char **value)
> +			       const char *name, char **value)
>  {
>  	const struct task_security_struct *__tsec;
>  	u32 sid;
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 001831458fa2..434b348d8fcd 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3479,7 +3479,7 @@ static void smack_d_instantiate(struct dentry
> *opt_dentry, struct inode *inode)
>   *
>   * Returns the length of the smack label or an error code
>   */
> -static int smack_getprocattr(struct task_struct *p, char *name, char
> **value)
> +static int smack_getprocattr(struct task_struct *p, const char *name, char
> **value)
>  {
>  	struct smack_known *skp = smk_of_task_struct_obj(p);
>  	char *cp;
> --
> 2.30.2