[PATCH 2/3] Send comm and cmdline in SCM_PROCINFO

From: Jan Kaluza
Date: Tue Aug 27 2013 - 10:42:16 EST

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Signed-off-by: Jan Kaluza <jkaluza@xxxxxxxxxx>
---
include/linux/socket.h | 2 ++
include/net/af_unix.h | 11 +++++++--
include/net/scm.h | 24 +++++++++++++++++++
net/core/scm.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++
net/unix/af_unix.c | 57 +++++++++++++++++++++++++++++++++++++------
5 files changed, 150 insertions(+), 9 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 505047a..6c7ace0 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -131,6 +131,8 @@ static inline struct cmsghdr * cmsg_nxthdr (struct msghdr *__msg, struct cmsghdr
#define SCM_CREDENTIALS 0x02 /* rw: struct ucred */
#define SCM_SECURITY 0x03 /* rw: security label */
#define SCM_AUDIT 0x04 /* rw: struct uaudit */
+#define SCM_PROCINFO 0x05 /* rw: comm + cmdline (NULL terminated
+ array of char *) */

struct ucred {
__u32 pid;
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 3b9d22a..05c7678 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -27,6 +27,13 @@ struct unix_address {
struct sockaddr_un name[0];
};

+struct unix_skb_parms_scm {
+ kuid_t loginuid;
+ unsigned int sessionid;
+ char *procinfo;
+ int procinfo_len;
+};
+
struct unix_skb_parms {
struct pid *pid; /* Skb credentials */
kuid_t uid;
@@ -36,12 +43,12 @@ struct unix_skb_parms {
u32 secid; /* Security ID */
#endif
u32 consumed;
- kuid_t loginuid;
- unsigned int sessionid;
+ struct unix_skb_parms_scm *scm;
};

#define UNIXCB(skb) (*(struct unix_skb_parms *)&((skb)->cb))
#define UNIXSID(skb) (&UNIXCB((skb)).secid)
+#define UNIXSCM(skb) (*(UNIXCB((skb)).scm))

#define unix_state_lock(s) spin_lock(&unix_sk(s)->lock)
#define unix_state_unlock(s) spin_unlock(&unix_sk(s)->lock)
diff --git a/include/net/scm.h b/include/net/scm.h
index e349a25..3346030 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -30,11 +30,17 @@ struct scm_fp_list {
struct file *fp[SCM_MAX_FD];
};

+struct scm_procinfo {
+ char *procinfo;
+ int len;
+};
+
struct scm_cookie {
struct pid *pid; /* Skb credentials */
struct scm_fp_list *fp; /* Passed files */
struct scm_creds creds; /* Skb credentials */
struct scm_audit audit; /* Skb audit */
+ struct scm_procinfo procinfo; /* Skb procinfo */
#ifdef CONFIG_SECURITY_NETWORK
u32 secid; /* Passed security ID */
#endif
@@ -45,6 +51,7 @@ extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
extern void __scm_destroy(struct scm_cookie *scm);
extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
+extern int scm_get_current_procinfo(char **procinfo);

#ifdef CONFIG_SECURITY_NETWORK
static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
@@ -72,10 +79,20 @@ static inline void scm_set_audit(struct scm_cookie *scm,
scm->audit.sessionid = sessionid;
}

+static inline void scm_set_procinfo(struct scm_cookie *scm,
+ char *procinfo, int len)
+{
+ scm->procinfo.procinfo = procinfo;
+ scm->procinfo.len = len;
+}
+
static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
{
put_pid(scm->pid);
scm->pid = NULL;
+ kfree(scm->procinfo.procinfo);
+ scm->procinfo.procinfo = NULL;
+ scm->procinfo.len = 0;
}

static __inline__ void scm_destroy(struct scm_cookie *scm)
@@ -88,6 +105,8 @@ static __inline__ void scm_destroy(struct scm_cookie *scm)
static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
struct scm_cookie *scm, bool forcecreds)
{
+ char *procinfo;
+ int len;
memset(scm, 0, sizeof(*scm));
scm->creds.uid = INVALID_UID;
scm->creds.gid = INVALID_GID;
@@ -96,6 +115,9 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
current_gid());
scm_set_audit(scm, audit_get_loginuid(current),
audit_get_sessionid(current));
+ len = scm_get_current_procinfo(&procinfo);
+ if (len > 0)
+ scm_set_procinfo(scm, procinfo, len);
}
unix_get_peersec_dgram(sock, scm);
if (msg->msg_controllen <= 0)
@@ -148,6 +170,8 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
};
put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
put_cmsg(msg, SOL_SOCKET, SCM_AUDIT, sizeof(uaudits), &uaudits);
+ put_cmsg(msg, SOL_SOCKET, SCM_PROCINFO, scm->procinfo.len,
+ scm->procinfo.procinfo);
}

scm_destroy_cred(scm);
diff --git a/net/core/scm.c b/net/core/scm.c
index 03795d0..09ec044 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -339,3 +339,68 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
return new_fpl;
}
EXPORT_SYMBOL(scm_fp_dup);
+
+int scm_get_current_procinfo(char **procinfo)
+{
+ int res = 0;
+ unsigned int len;
+ char *buffer = NULL;
+ struct mm_struct *mm;
+ int comm_len = strlen(current->comm);
+
+ *procinfo = NULL;
+
+ buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ mm = get_task_mm(current);
+ if (!mm)
+ goto out;
+ if (!mm->arg_end)
+ goto out_mm; /* Shh! No looking before we're done */
+
+ len = mm->arg_end - mm->arg_start;
+
+ if (len > PAGE_SIZE)
+ len = PAGE_SIZE;
+
+ res = access_process_vm(current, mm->arg_start, buffer, len, 0);
+
+ /* If the nul at the end of args has been overwritten, then
+ * assume application is using setproctitle(3).
+ */
+ if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
+ len = strnlen(buffer, res);
+ if (len < res) {
+ res = len;
+ } else {
+ len = mm->env_end - mm->env_start;
+ if (len > PAGE_SIZE - res)
+ len = PAGE_SIZE - res;
+ res += access_process_vm(current, mm->env_start,
+ buffer+res, len, 0);
+ res = strnlen(buffer, res);
+ }
+ }
+
+ /* strlen(comm) + \0 + len of cmdline */
+ len = comm_len + 1 + res;
+ *procinfo = kmalloc(len, GFP_KERNEL);
+ if (!*procinfo) {
+ res = -ENOMEM;
+ goto out_mm;
+ }
+
+ memcpy(*procinfo, current->comm, comm_len + 1); /* include \0 */
+ if (res > 0)
+ memcpy(*procinfo + comm_len + 1, buffer, res);
+ res = len;
+
+out_mm:
+ mmput(mm);
+out:
+ kfree(buffer);
+ return res;
+}
+EXPORT_SYMBOL(scm_get_current_procinfo);
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index c410f76..ab0be13 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1341,9 +1341,14 @@ static void unix_destruct_scm(struct sk_buff *skb)
struct scm_cookie scm;
memset(&scm, 0, sizeof(scm));
scm.pid = UNIXCB(skb).pid;
+ if (UNIXCB(skb).scm) {
+ scm.procinfo.procinfo = UNIXSCM(skb).procinfo;
+ scm.procinfo.len = UNIXSCM(skb).procinfo_len;
+ }
if (UNIXCB(skb).fp)
unix_detach_fds(&scm, skb);

+ kfree(UNIXCB(skb).scm);
/* Alas, it calls VFS */
/* So fscking what? fput() had been SMP-safe since the last Summer */
scm_destroy(&scm);
@@ -1390,15 +1395,31 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
{
int err = 0;

+ if (!UNIXCB(skb).scm) {
+ UNIXCB(skb).scm = kmalloc(sizeof(struct unix_skb_parms_scm),
+ GFP_KERNEL);
+ if (!UNIXCB(skb).scm)
+ return -ENOMEM;
+ }
+
UNIXCB(skb).pid = get_pid(scm->pid);
UNIXCB(skb).uid = scm->creds.uid;
UNIXCB(skb).gid = scm->creds.gid;
- UNIXCB(skb).loginuid = scm->audit.loginuid;
- UNIXCB(skb).sessionid = scm->audit.sessionid;
+ UNIXSCM(skb).loginuid = scm->audit.loginuid;
+ UNIXSCM(skb).sessionid = scm->audit.sessionid;
UNIXCB(skb).fp = NULL;
if (scm->fp && send_fds)
err = unix_attach_fds(scm, skb);

+ UNIXSCM(skb).procinfo = NULL;
+ if (scm->procinfo.procinfo) {
+ UNIXSCM(skb).procinfo_len = scm->procinfo.len;
+ UNIXSCM(skb).procinfo = kmemdup(scm->procinfo.procinfo,
+ scm->procinfo.len, GFP_KERNEL);
+ if (!UNIXSCM(skb).procinfo)
+ return -ENOMEM;
+ }
+
skb->destructor = unix_destruct_scm;
return err;
}
@@ -1418,8 +1439,10 @@ static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
UNIXCB(skb).pid = get_pid(task_tgid(current));
current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid);
- UNIXCB(skb).loginuid = audit_get_loginuid(current);
- UNIXCB(skb).sessionid = audit_get_sessionid(current);
+ UNIXSCM(skb).loginuid = audit_get_loginuid(current);
+ UNIXSCM(skb).sessionid = audit_get_sessionid(current);
+ UNIXSCM(skb).procinfo_len = scm_get_current_procinfo(
+ &UNIXSCM(skb).procinfo);
}
}

@@ -1816,7 +1839,17 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
memset(&tmp_scm, 0, sizeof(tmp_scm));
}
scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
- scm_set_audit(siocb->scm, UNIXCB(skb).loginuid, UNIXCB(skb).sessionid);
+ if (UNIXCB(skb).scm) {
+ scm_set_audit(siocb->scm, UNIXSCM(skb).loginuid,
+ UNIXSCM(skb).sessionid);
+ if (UNIXSCM(skb).procinfo) {
+ scm_set_procinfo(siocb->scm,
+ kmemdup(UNIXSCM(skb).procinfo,
+ UNIXSCM(skb).procinfo_len,
+ GFP_KERNEL),
+ UNIXSCM(skb).procinfo_len);
+ }
+ }
unix_set_secdata(siocb->scm, skb);

if (!(flags & MSG_PEEK)) {
@@ -1998,8 +2031,18 @@ again:
} else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
/* Copy credentials */
scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
- scm_set_audit(siocb->scm, UNIXCB(skb).loginuid,
- UNIXCB(skb).sessionid);
+ if (UNIXCB(skb).scm) {
+ scm_set_audit(siocb->scm,
+ UNIXSCM(skb).loginuid,
+ UNIXSCM(skb).sessionid);
+ if (UNIXSCM(skb).procinfo) {
+ scm_set_procinfo(siocb->scm,
+ kmemdup(UNIXSCM(skb).procinfo,
+ UNIXSCM(skb).procinfo_len,
+ GFP_KERNEL),
+ UNIXSCM(skb).procinfo_len);
+ }
+ }
check_creds = 1;
}

--
1.8.3.1

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Next message: Jason Cooper: "Re: [PATCH v5 0/3] arm: mvebu: fix resource leak"
Previous message: Jan Kaluza: "[PATCH 3/3] Send cgroup_path in SCM_CGROUP"
In reply to: Tejun Heo: "Re: [PATCH 3/3] Send cgroup_path in SCM_CGROUP"
Next in thread: Jan Kaluza: "[PATCH v2 0/3] Send audit/procinfo/cgroup data in socket-level control message"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]