diff options
| author | Taehee Yoo <ap420073@gmail.com> | 2019-07-02 18:20:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-26 10:12:50 +0300 |
| commit | bf75202df8e473d4ee914894542f213158066d8b (patch) | |
| tree | 56754f53e88657a9d0370ff5400896f803df3b46 /drivers/net | |
| parent | 572af11ec2252a9c57cc6ee5e247ebe04da18bb7 (diff) | |
| download | linux-bf75202df8e473d4ee914894542f213158066d8b.tar.xz | |
gtp: fix suspicious RCU usage
[ Upstream commit e198987e7dd7d3645a53875151cd6f8fc425b706 ]
gtp_encap_enable_socket() and gtp_encap_destroy() are not protected
by rcu_read_lock(). and it's not safe to write sk->sk_user_data.
This patch make these functions to use lock_sock() instead of
rcu_dereference_sk_user_data().
Test commands:
gtp-link add gtp1
Splat looks like:
[ 83.238315] =============================
[ 83.239127] WARNING: suspicious RCU usage
[ 83.239702] 5.2.0-rc6+ #49 Not tainted
[ 83.240268] -----------------------------
[ 83.241205] drivers/net/gtp.c:799 suspicious rcu_dereference_check() usage!
[ 83.243828]
[ 83.243828] other info that might help us debug this:
[ 83.243828]
[ 83.246325]
[ 83.246325] rcu_scheduler_active = 2, debug_locks = 1
[ 83.247314] 1 lock held by gtp-link/1008:
[ 83.248523] #0: 0000000017772c7f (rtnl_mutex){+.+.}, at: __rtnl_newlink+0x5f5/0x11b0
[ 83.251503]
[ 83.251503] stack backtrace:
[ 83.252173] CPU: 0 PID: 1008 Comm: gtp-link Not tainted 5.2.0-rc6+ #49
[ 83.253271] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 83.254562] Call Trace:
[ 83.254995] dump_stack+0x7c/0xbb
[ 83.255567] gtp_encap_enable_socket+0x2df/0x360 [gtp]
[ 83.256415] ? gtp_find_dev+0x1a0/0x1a0 [gtp]
[ 83.257161] ? memset+0x1f/0x40
[ 83.257843] gtp_newlink+0x90/0xa21 [gtp]
[ 83.258497] ? __netlink_ns_capable+0xc3/0xf0
[ 83.259260] __rtnl_newlink+0xb9f/0x11b0
[ 83.260022] ? rtnl_link_unregister+0x230/0x230
[ ... ]
Fixes: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/gtp.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 83488f2bf7a0..f45a806b6c06 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -293,12 +293,14 @@ static void gtp_encap_destroy(struct sock *sk) { struct gtp_dev *gtp; - gtp = rcu_dereference_sk_user_data(sk); + lock_sock(sk); + gtp = sk->sk_user_data; if (gtp) { udp_sk(sk)->encap_type = 0; rcu_assign_sk_user_data(sk, NULL); sock_put(sk); } + release_sock(sk); } static void gtp_encap_disable_sock(struct sock *sk) @@ -800,7 +802,8 @@ static struct sock *gtp_encap_enable_socket(int fd, int type, goto out_sock; } - if (rcu_dereference_sk_user_data(sock->sk)) { + lock_sock(sock->sk); + if (sock->sk->sk_user_data) { sk = ERR_PTR(-EBUSY); goto out_sock; } @@ -816,6 +819,7 @@ static struct sock *gtp_encap_enable_socket(int fd, int type, setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); out_sock: + release_sock(sock->sk); sockfd_put(sock); return sk; } |