Message ID | 20211214043208.3543046-1-eric.dumazet@gmail.com (mailing list archive) |
---|---|
State | Accepted |
Commit | 1d2f3d3c62684b793339d0ae841ac67b555d8c8d |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | [net-next] mptcp: adjust to use netns refcount tracker | expand |
On Mon, 2021-12-13 at 20:32 -0800, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > MPTCP can change sk_net_refcnt after sock_create_kern() call. > > We need to change its corresponding get_net() to avoid > a splat at release time, as in : > > refcount_t: decrement hit 0; leaking memory. > WARNING: CPU: 0 PID: 3599 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 > Modules linked in: > CPU: 1 PID: 3599 Comm: syz-fuzzer Not tainted 5.16.0-rc4-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 > Code: 1d b1 99 a1 09 31 ff 89 de e8 5d 3a 9c fd 84 db 75 e0 e8 74 36 9c fd 48 c7 c7 60 00 05 8a c6 05 91 99 a1 09 01 e8 cc 4b 27 05 <0f> 0b eb c4 e8 58 36 9c fd 0f b6 1d 80 99 a1 09 31 ff 89 de e8 28 > RSP: 0018:ffffc90001f5fab0 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: ffff888021873a00 RSI: ffffffff815f1e28 RDI: fffff520003ebf48 > RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 > R10: ffffffff815ebbce R11: 0000000000000000 R12: 1ffff920003ebf5b > R13: 00000000ffffffef R14: ffffffff8d2fcd94 R15: ffffc90001f5fd10 > FS: 000000c00008a090(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f0a5b59e300 CR3: 000000001cbe6000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > __refcount_dec include/linux/refcount.h:344 [inline] > refcount_dec include/linux/refcount.h:359 [inline] > ref_tracker_free+0x4fe/0x610 lib/ref_tracker.c:101 > netns_tracker_free include/net/net_namespace.h:327 [inline] > put_net_track include/net/net_namespace.h:341 [inline] > __sk_destruct+0x4a6/0x920 net/core/sock.c:2042 > sk_destruct+0xbd/0xe0 net/core/sock.c:2058 > __sk_free+0xef/0x3d0 net/core/sock.c:2069 > sk_free+0x78/0xa0 net/core/sock.c:2080 > sock_put include/net/sock.h:1911 [inline] > __mptcp_close_ssk+0x435/0x590 net/mptcp/protocol.c:2276 > __mptcp_destroy_sock+0x35f/0x830 net/mptcp/protocol.c:2702 > mptcp_close+0x5f8/0x7f0 net/mptcp/protocol.c:2750 > inet_release+0x12e/0x280 net/ipv4/af_inet.c:428 > inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:476 > __sock_release+0xcd/0x280 net/socket.c:649 > sock_close+0x18/0x20 net/socket.c:1314 > __fput+0x286/0x9f0 fs/file_table.c:280 > task_work_run+0xdd/0x1a0 kernel/task_work.c:164 > tracehook_notify_resume include/linux/tracehook.h:189 [inline] > exit_to_user_mode_loop kernel/entry/common.c:175 [inline] > exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 > __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] > syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 > do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Fixes: ffa84b5ffb37 ("net: add netns refcount tracker to struct sock") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: syzbot <syzkaller@googlegroups.com> > Cc: Mat Martineau <mathew.j.martineau@linux.intel.com> > Cc: Matthieu Baerts <matthieu.baerts@tessares.net> > Cc: Florian Westphal <fw@strlen.de> > Cc: Paolo Abeni <pabeni@redhat.com> > --- > net/mptcp/subflow.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c > index b8dd3441f7d00357dfac6121f6288b9300ea5201..24bc9d5e87be44542f5094cda39dcc59f8f9f10d 100644 > --- a/net/mptcp/subflow.c > +++ b/net/mptcp/subflow.c > @@ -1534,7 +1534,7 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) > * needs it. > */ > sf->sk->sk_net_refcnt = 1; > - get_net(net); > + get_net_track(net, &sf->sk->ns_tracker, GFP_KERNEL); > sock_inuse_add(net, 1); > err = tcp_set_ulp(sf->sk, "mptcp"); > release_sock(sf->sk); LGTM, thanks Eric! (and more thanks for the whole tracking infra!) Acked-by: Paolo Abeni <pabeni@redhat.com>
Hi Eric, On 14/12/2021 05:32, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > MPTCP can change sk_net_refcnt after sock_create_kern() call. Thank you for the fix and the new tracking infra! Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Cheers, Matt
Hello: This patch was applied to netdev/net-next.git (master) by Jakub Kicinski <kuba@kernel.org>: On Mon, 13 Dec 2021 20:32:08 -0800 you wrote: > From: Eric Dumazet <edumazet@google.com> > > MPTCP can change sk_net_refcnt after sock_create_kern() call. > > We need to change its corresponding get_net() to avoid > a splat at release time, as in : > > [...] Here is the summary with links: - [net-next] mptcp: adjust to use netns refcount tracker https://git.kernel.org/netdev/net-next/c/1d2f3d3c6268 You are awesome, thank you!
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index b8dd3441f7d00357dfac6121f6288b9300ea5201..24bc9d5e87be44542f5094cda39dcc59f8f9f10d 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1534,7 +1534,7 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) * needs it. */ sf->sk->sk_net_refcnt = 1; - get_net(net); + get_net_track(net, &sf->sk->ns_tracker, GFP_KERNEL); sock_inuse_add(net, 1); err = tcp_set_ulp(sf->sk, "mptcp"); release_sock(sf->sk);