| Message ID | ebc7594cdd420d241fb2172ddb8542ba64717657.1639238695.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | b0cdc5dbcf2ba0d99785da5aabf1b17943805b8a |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] mptcp: never allow the PM to close a listener subflow | expand |
On Sat, 11 Dec 2021, Paolo Abeni wrote: > Currently, when deleting an endpoint the netlink PM treverses > all the local MPTCP sockets, regardless of their status. > > If an MPTCP listener socket is bound to the IP matching the > delete endpoint, the listener TCP socket will be closed. > That is unexpected, the PM should only affect data subflows. > > Additionally, syzbot was able to trigger a NULL ptr dereference > due to the above: > > general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] > CPU: 1 PID: 6550 Comm: syz-executor122 Not tainted 5.16.0-rc4-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897 > Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff > RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016 > RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000 > RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001 > RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000 > R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001 > FS: 00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0 > Call Trace: > <TASK> > lock_acquire kernel/locking/lockdep.c:5637 [inline] > lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 > finish_wait+0xc0/0x270 kernel/sched/wait.c:400 > inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:464 [inline] > inet_csk_accept+0x7de/0x9d0 net/ipv4/inet_connection_sock.c:497 > mptcp_accept+0xe5/0x500 net/mptcp/protocol.c:2865 > inet_accept+0xe4/0x7b0 net/ipv4/af_inet.c:739 > mptcp_stream_accept+0x2e7/0x10e0 net/mptcp/protocol.c:3345 > do_accept+0x382/0x510 net/socket.c:1773 > __sys_accept4_file+0x7e/0xe0 net/socket.c:1816 > __sys_accept4+0xb0/0x100 net/socket.c:1846 > __do_sys_accept net/socket.c:1864 [inline] > __se_sys_accept net/socket.c:1861 [inline] > __x64_sys_accept+0x71/0xb0 net/socket.c:1861 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x7f177cd8b8e9 > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007f177cd3d308 EFLAGS: 00000246 ORIG_RAX: 000000000000002b > RAX: ffffffffffffffda RBX: 00007f177ce13408 RCX: 00007f177cd8b8e9 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: 00007f177ce13400 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f177ce1340c > R13: 00007f177cde1004 R14: 6d705f706374706d R15: 0000000000022000 > </TASK> > > Fix the issue explicitly skipping MPTCP socket in TCP_LISTEN > status. > > Reported-and-tested-by: syzbot+e4d843bb96a9431e6331@syzkaller.appspotmail.com > Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Just re-confirming that I'd like to see this merged for the -net branch! Thanks, Mat > Fixes: 740d798e8767 ("mptcp: remove id 0 address") > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > --- > net/mptcp/pm_netlink.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c > index 7b96be1e9f14..f523051f5aef 100644 > --- a/net/mptcp/pm_netlink.c > +++ b/net/mptcp/pm_netlink.c > @@ -700,6 +700,9 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, > > msk_owned_by_me(msk); > > + if (sk->sk_state == TCP_LISTEN) > + return; > + > if (!rm_list->nr) > return; > > -- > 2.33.1 > > > -- Mat Martineau Intel
Hello: This patch was applied to netdev/net.git (master) by Jakub Kicinski <kuba@kernel.org>: On Sat, 11 Dec 2021 17:11:12 +0100 you wrote: > Currently, when deleting an endpoint the netlink PM treverses > all the local MPTCP sockets, regardless of their status. > > If an MPTCP listener socket is bound to the IP matching the > delete endpoint, the listener TCP socket will be closed. > That is unexpected, the PM should only affect data subflows. > > [...] Here is the summary with links: - [net] mptcp: never allow the PM to close a listener subflow https://git.kernel.org/netdev/net/c/b0cdc5dbcf2b You are awesome, thank you!
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 7b96be1e9f14..f523051f5aef 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -700,6 +700,9 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, msk_owned_by_me(msk); + if (sk->sk_state == TCP_LISTEN) + return; + if (!rm_list->nr) return;