nsfs: validate ioctls

Nsfs supports extensible and non-extensible ioctls. Validate both types
to prevent confusion.

Link: https://lore.kernel.org/r/20250219-work-nsfs-v1-1-21128d73c5e8@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-02-19 17:40:28 +01:00
parent 2014c95afe
commit 7fd511f8c9
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 31 additions and 1 deletions

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@ -152,19 +152,49 @@ static int copy_ns_info_to_user(const struct mnt_namespace *mnt_ns,
return 0;
}
static bool nsfs_ioctl_valid(unsigned int cmd)
{
switch (cmd) {
case NS_GET_USERNS:
case NS_GET_PARENT:
case NS_GET_NSTYPE:
case NS_GET_OWNER_UID:
case NS_GET_MNTNS_ID:
case NS_GET_PID_FROM_PIDNS:
case NS_GET_TGID_FROM_PIDNS:
case NS_GET_PID_IN_PIDNS:
case NS_GET_TGID_IN_PIDNS:
return (_IOC_TYPE(cmd) == _IOC_TYPE(cmd));
}
/* Extensible ioctls require some extra handling. */
switch (_IOC_NR(cmd)) {
case _IOC_NR(NS_MNT_GET_INFO):
case _IOC_NR(NS_MNT_GET_NEXT):
case _IOC_NR(NS_MNT_GET_PREV):
return (_IOC_TYPE(cmd) == _IOC_TYPE(cmd));
}
return false;
}
static long ns_ioctl(struct file *filp, unsigned int ioctl,
unsigned long arg)
{
struct user_namespace *user_ns;
struct pid_namespace *pid_ns;
struct task_struct *tsk;
struct ns_common *ns = get_proc_ns(file_inode(filp));
struct ns_common *ns;
struct mnt_namespace *mnt_ns;
bool previous = false;
uid_t __user *argp;
uid_t uid;
int ret;
if (!nsfs_ioctl_valid(ioctl))
return -ENOIOCTLCMD;
ns = get_proc_ns(file_inode(filp));
switch (ioctl) {
case NS_GET_USERNS:
return open_related_ns(ns, ns_get_owner);