Re: [Patch net] tipc: use the right skb in tipc_sk_fill_sock_diag()

[David Miller]

From: Cong Wang 
Date: Fri,  6 Apr 2018 18:54:52 -0700

> Commit 4b2e6877b879 ("tipc: Fix namespace violation in 
> tipc_sk_fill_sock_diag")
> tried to fix the crash but failed, the crash is still 100% reproducible
> with it.
> 
> In tipc_sk_fill_sock_diag(), skb is the diag dump we are filling, it is not
> correct to retrieve its NETLINK_CB(), instead, like other protocol diag,
> we should use NETLINK_CB(cb->skb).sk here.
> 
> Reported-by: 
> Fixes: 4b2e6877b879 ("tipc: Fix namespace violation in 
> tipc_sk_fill_sock_diag")
> Fixes: c30b70deb5f4 (tipc: implement socket diagnostics for AF_TIPC)
> Cc: GhantaKrishnamurthy MohanKrishna 
> 
> Cc: Jon Maloy 
> Cc: Ying Xue 
> Signed-off-by: Cong Wang 

Applied, thank you.

[Patch net] tipc: use the right skb in tipc_sk_fill_sock_diag()

[Cong Wang]

Commit 4b2e6877b879 ("tipc: Fix namespace violation in tipc_sk_fill_sock_diag")
tried to fix the crash but failed, the crash is still 100% reproducible
with it.

In tipc_sk_fill_sock_diag(), skb is the diag dump we are filling, it is not
correct to retrieve its NETLINK_CB(), instead, like other protocol diag,
we should use NETLINK_CB(cb->skb).sk here.

Reported-by: 
Fixes: 4b2e6877b879 ("tipc: Fix namespace violation in tipc_sk_fill_sock_diag")
Fixes: c30b70deb5f4 (tipc: implement socket diagnostics for AF_TIPC)
Cc: GhantaKrishnamurthy MohanKrishna 

Cc: Jon Maloy 
Cc: Ying Xue 
Signed-off-by: Cong Wang 
---
 net/tipc/diag.c   | 2 +-
 net/tipc/socket.c | 6 +++---
 net/tipc/socket.h | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/tipc/diag.c b/net/tipc/diag.c
index 46d9cd62f781..aaabb0b776dd 100644
--- a/net/tipc/diag.c
+++ b/net/tipc/diag.c
@@ -59,7 +59,7 @@ static int __tipc_add_sock_diag(struct sk_buff *skb,
if (!nlh)
return -EMSGSIZE;
 
-   err = tipc_sk_fill_sock_diag(skb, tsk, req->tidiag_states,
+   err = tipc_sk_fill_sock_diag(skb, cb, tsk, req->tidiag_states,
 __tipc_diag_gen_cookie);
if (err)
return err;
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index cee6674a3bf4..1fd1c8b5ce03 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3257,8 +3257,8 @@ int tipc_nl_sk_walk(struct sk_buff *skb, struct 
netlink_callback *cb,
 }
 EXPORT_SYMBOL(tipc_nl_sk_walk);
 
-int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct tipc_sock *tsk,
-  u32 sk_filter_state,
+int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct netlink_callback *cb,
+  struct tipc_sock *tsk, u32 sk_filter_state,
   u64 (*tipc_diag_gen_cookie)(struct sock *sk))
 {
struct sock *sk = >sk;
@@ -3280,7 +3280,7 @@ int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct 
tipc_sock *tsk,
nla_put_u32(skb, TIPC_NLA_SOCK_TIPC_STATE, (u32)sk->sk_state) ||
nla_put_u32(skb, TIPC_NLA_SOCK_INO, sock_i_ino(sk)) ||
nla_put_u32(skb, TIPC_NLA_SOCK_UID,
-   from_kuid_munged(sk_user_ns(NETLINK_CB(skb).sk),
+   from_kuid_munged(sk_user_ns(NETLINK_CB(cb->skb).sk),
 sock_i_uid(sk))) ||
nla_put_u64_64bit(skb, TIPC_NLA_SOCK_COOKIE,
  tipc_diag_gen_cookie(sk),
diff --git a/net/tipc/socket.h b/net/tipc/socket.h
index aae3fd4cd06c..aff9b2ae5a1f 100644
--- a/net/tipc/socket.h
+++ b/net/tipc/socket.h
@@ -61,8 +61,8 @@ int tipc_sk_rht_init(struct net *net);
 void tipc_sk_rht_destroy(struct net *net);
 int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_publ_dump(struct sk_buff *skb, struct netlink_callback *cb);
-int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct tipc_sock *tsk,
-  u32 sk_filter_state,
+int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct netlink_callback *cb,
+  struct tipc_sock *tsk, u32 sk_filter_state,
   u64 (*tipc_diag_gen_cookie)(struct sock *sk));
 int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
int (*skb_handler)(struct sk_buff *skb,
-- 
2.13.0