diff options
Diffstat (limited to 'net/core/scm.c')
| -rw-r--r-- | net/core/scm.c | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/net/core/scm.c b/net/core/scm.c index 0225bd94170f..072d5742440a 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -23,6 +23,8 @@ #include <linux/security.h> #include <linux/pid_namespace.h> #include <linux/pid.h> +#include <uapi/linux/pidfd.h> +#include <linux/pidfs.h> #include <linux/nsproxy.h> #include <linux/slab.h> #include <linux/errqueue.h> @@ -145,6 +147,22 @@ void __scm_destroy(struct scm_cookie *scm) } EXPORT_SYMBOL(__scm_destroy); +static inline int scm_replace_pid(struct scm_cookie *scm, struct pid *pid) +{ + int err; + + /* drop all previous references */ + scm_destroy_cred(scm); + + err = pidfs_register_pid(pid); + if (unlikely(err)) + return err; + + scm->pid = pid; + scm->creds.pid = pid_vnr(pid); + return 0; +} + int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p) { const struct proto_ops *ops = READ_ONCE(sock->ops); @@ -189,15 +207,21 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p) if (err) goto error; - p->creds.pid = creds.pid; if (!p->pid || pid_vnr(p->pid) != creds.pid) { struct pid *pid; err = -ESRCH; pid = find_get_pid(creds.pid); if (!pid) goto error; - put_pid(p->pid); - p->pid = pid; + + /* pass a struct pid reference from + * find_get_pid() to scm_replace_pid(). + */ + err = scm_replace_pid(p, pid); + if (err) { + put_pid(pid); + goto error; + } } err = -EINVAL; @@ -459,7 +483,7 @@ static void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm) if (!scm->pid) return; - pidfd = pidfd_prepare(scm->pid, 0, &pidfd_file); + pidfd = pidfd_prepare(scm->pid, PIDFD_STALE, &pidfd_file); if (put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd)) { if (pidfd_file) { |