From: Geliang Tang <tanggeliang@kylinos.cn>

In mptcp_pm_nl_set_flags(), "entry" is copied to "local" when pernet->lock

is held to avoid direct access to entry without pernet->lock.

Therefore, "local->flags" should be passed to mptcp_nl_set_flags instead

of "entry->flags" when pernet->lock is not held, so as to avoid access to

entry.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>

---

net/mptcp/pm_netlink.c | 2 +-

1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c

index XXXXXXX..XXXXXXX 100644

--- a/net/mptcp/pm_netlink.c

+++ b/net/mptcp/pm_netlink.c

@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,

    *local = *entry;

    spin_unlock_bh(&pernet->lock);

-    mptcp_nl_set_flags(net, &local->addr, entry->flags, changed);

+    mptcp_nl_set_flags(net, &local->addr, local->flags, changed);

    return 0;

}

--

2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

The number of parameters in mptcp_nl_set_flags() can be reduced.

Only need to pass a "local" parameter to it instead of "local->addr"

and "local->flags".

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>

---

net/mptcp/pm_netlink.c | 15 ++++++++-------

1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c

index XXXXXXX..XXXXXXX 100644

--- a/net/mptcp/pm_netlink.c

+++ b/net/mptcp/pm_netlink.c

@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,

    spin_unlock_bh(&msk->pm.lock);

}

-static void mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr,

-             u8 flags, u8 changed)

+static void mptcp_nl_set_flags(struct net *net,

+             struct mptcp_pm_addr_entry *local,

+             u8 changed)

{

-    u8 is_subflow = !!(flags & MPTCP_PM_ADDR_FLAG_SUBFLOW);

-    u8 bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);

+    u8 is_subflow = !!(local->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW);

+    u8 bkup = !!(local->flags & MPTCP_PM_ADDR_FLAG_BACKUP);

    long s_slot = 0, s_num = 0;

    struct mptcp_sock *msk;

@@ -XXX,XX +XXX,XX @@ static void mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr,

        lock_sock(sk);

        if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)

-            mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);

+            mptcp_pm_nl_mp_prio_send_ack(msk, &local->addr, NULL, bkup);

        /* Subflows will only be recreated if the SUBFLOW flag is set */

        if (is_subflow && (changed & MPTCP_PM_ADDR_FLAG_FULLMESH))

-            mptcp_pm_nl_fullmesh(msk, addr);

+            mptcp_pm_nl_fullmesh(msk, &local->addr);

        release_sock(sk);

next:

@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,

    *local = *entry;

    spin_unlock_bh(&pernet->lock);

-    mptcp_nl_set_flags(net, &local->addr, local->flags, changed);

+    mptcp_nl_set_flags(net, local, changed);

    return 0;

}

--

2.43.0

-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)

+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,

+             struct mptcp_pm_addr_entry *skc)

{

    struct mptcp_pm_addr_entry *entry;

    struct pm_nl_pernet *pernet;

@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc

    pernet = pm_nl_get_pernet_from_msk(msk);

    rcu_read_lock();

-    entry = __lookup_addr(pernet, skc);

+    entry = __lookup_addr(pernet, &skc->addr);

    ret = entry ? entry->addr.id : -1;

    rcu_read_unlock();

    if (ret >= 0)

@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc

    if (!entry)

        return -ENOMEM;

-    entry->addr = *skc;

-    entry->addr.id = 0;

+    *entry = *skc;

    entry->addr.port = 0;

-    entry->ifindex = 0;

-    entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;

-    entry->lsk = NULL;

    ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);

    if (ret < 0)

        kfree(entry);

-    struct mptcp_pm_addr_entry *entry = NULL, new_entry;

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds the sock version of kmemdup() helper, named sock_kmemdup(),

to duplicate a memory block using the socket's option memory buffer.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>

---

include/net/sock.h | 1 +

net/core/sock.c | 23 +++++++++++++++++++++++

2 files changed, 24 insertions(+)

diff --git a/include/net/sock.h b/include/net/sock.h

index XXXXXXX..XXXXXXX 100644

--- a/include/net/sock.h

+++ b/include/net/sock.h

@@ -XXX,XX +XXX,XX @@ static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,

}

void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);

+void *sock_kmemdup(struct sock *sk, const void *src, int size, gfp_t priority);

void sock_kfree_s(struct sock *sk, void *mem, int size);

void sock_kzfree_s(struct sock *sk, void *mem, int size);

void sk_send_sigurg(struct sock *sk);

diff --git a/net/core/sock.c b/net/core/sock.c

index XXXXXXX..XXXXXXX 100644

--- a/net/core/sock.c

+++ b/net/core/sock.c

@@ -XXX,XX +XXX,XX @@ void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)

}

EXPORT_SYMBOL(sock_kmalloc);

+/*

+ * Duplicate a memory block using the socket's option memory buffer.

+ */

+void *sock_kmemdup(struct sock *sk, const void *src, int size, gfp_t priority)

+{

+    int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);

+

+    if ((unsigned int)size <= optmem_max &&

+     atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {

+        void *mem;

+        /* First do the add, to avoid the race if kmalloc

+         * might sleep.

+         */

+        atomic_add(size, &sk->sk_omem_alloc);

+        mem = kmemdup(src, size, priority);

+        if (mem)

+            return mem;

+        atomic_sub(size, &sk->sk_omem_alloc);

+    }

+    return NULL;

+}

+EXPORT_SYMBOL(sock_kmemdup);

+

/* Free an option memory block. Note, we actually want the inline

* here as this allows gcc to detect the nullify and fold away the

* condition entirely.

--

2.43.0