diff options
| author | Tetsuo Handa | 2022-05-02 10:40:18 +0900 |
|---|---|---|
| committer | Paolo Abeni | 2022-05-03 13:22:50 +0200 |
| commit | 3a58f13a881ed351198ffab4cf9953cf19d2ab3a (patch) | |
| tree | 3eda76075a30db339d54da4746f32546448acc0f /net | |
| parent | f5c2174a3775491e890ce285df52f5715fbef875 (diff) | |
net: rds: acquire refcount on TCP sockets
syzbot is reporting use-after-free read in tcp_retransmit_timer() [1],
for TCP socket used by RDS is accessing sock_net() without acquiring a
refcount on net namespace. Since TCP's retransmission can happen after
a process which created net namespace terminated, we need to explicitly
acquire a refcount.
Link: https://syzkaller.appspot.com/bug?extid=694120e1002c117747ed [1]
Reported-by: syzbot <syzbot+694120e1002c117747ed@syzkaller.appspotmail.com>
Fixes: 26abe14379f8e2fa ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Fixes: 8a68173691f03661 ("net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+694120e1002c117747ed@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/r/a5fb1fc4-2284-3359-f6a0-e4e390239d7b@I-love.SAKURA.ne.jp
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/rds/tcp.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/rds/tcp.c b/net/rds/tcp.c index 5327d130c4b5..2f638f8b7b1e 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -495,6 +495,14 @@ void rds_tcp_tune(struct socket *sock) tcp_sock_set_nodelay(sock->sk); lock_sock(sk); + /* TCP timer functions might access net namespace even after + * a process which created this net namespace terminated. + */ + if (!sk->sk_net_refcnt) { + sk->sk_net_refcnt = 1; + get_net_track(net, &sk->ns_tracker, GFP_KERNEL); + sock_inuse_add(net, 1); + } if (rtn->sndbuf_size > 0) { sk->sk_sndbuf = rtn->sndbuf_size; sk->sk_userlocks |= SOCK_SNDBUF_LOCK; |