| From 49c896c9c7d30fa84a5e3b4bdfd0620d8164661e Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sat, 11 Dec 2021 17:11:12 +0100 |
| Subject: mptcp: never allow the PM to close a listener subflow |
| |
| From: Paolo Abeni <pabeni@redhat.com> |
| |
| [ Upstream commit b0cdc5dbcf2ba0d99785da5aabf1b17943805b8a ] |
| |
| 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> |
| Fixes: 740d798e8767 ("mptcp: remove id 0 address") |
| Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
| Link: https://lore.kernel.org/r/ebc7594cdd420d241fb2172ddb8542ba64717657.1639238695.git.pabeni@redhat.com |
| Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 050eea231528b..b79251a36dcbc 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; |
| |
| -- |
| 2.33.0 |
| |