From patchwork Mon May 6 12:30:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13655371 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 379CDB672 for ; Mon, 6 May 2024 12:30:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714998636; cv=none; b=ZFe3MTvp3PqngNbhtGkF8cVUgmoCKIj2k/DgLj3FpjDU5dpq/nBuVnOWRuisGAAJHDRlE+oCYZGYKf+nADPAytHTWe1viFcgLQX8mHNdY/m/LcQq/J7QpPB3zn5rBDSlbmJjXc4w8UW3VjNs0zaNsZOvEmRLwkg7bj9NmQ5jlWw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714998636; c=relaxed/simple; bh=dHkAFoPK9igsh3hBPxZ0BoPVhsZFVy+Byd3Z8YXctN0=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=G+m/S1UQF5odos3jo9ZKP/svvJ0DONLNv8vxAHWhR+N3aUpqIu5i0EmlF6CPPwSb7MlPd92SEEtpiUAm6b/wKOXAMkKrYgApNQOsE2VPNEKcQ/gGwwTehQU/0U5JDPAZbV38VnaH0Rr4tKBCxGCasmv7/hS+AjwZqE5K6XqEirM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=i8nD0Ge1; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="i8nD0Ge1" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-61b1200cc92so35686547b3.0 for ; Mon, 06 May 2024 05:30:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1714998634; x=1715603434; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=JLW66EGcoAduSwef0VL9DG+1mWQHwTuV/UM4MbZqh1o=; b=i8nD0Ge1Jy/OEjkL6YFtWJv7ZWvEKZYOfJqI/Wrewq13sO2fZaYrgk4jhvPVUsmb3j 8nOhiKvJZhIm4JwLfKrSxxUd+3MVL/0NtjBzybiTkH/1cbHL9LmOLDV2O1/uP4FKrw+C AzNxoalsO0RzEilPRCm5ygleO14/WV+89Z6w37TdhafC70/7uRa5lcXhj8mWz77eZdcI SFJBThpKC8trZdu+sEygIXxz2o9/xSpQGk4/VluUFScJGmIdCFmuOQiOdb9urjH4FLtl GiIFEM4aAJ4pFcTMYHkxmBgJUnwEB+KTe28FXTpD24941qDeMdZ5vtloHBofrAt9baHX svZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714998634; x=1715603434; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=JLW66EGcoAduSwef0VL9DG+1mWQHwTuV/UM4MbZqh1o=; b=ccS3B24Q9J+hExHBKuiQbvZO3k+eRkwiwVNHzbaH0B0+n4k5L3vFVyqzyxWuolrdFL GzTPdriqjjwbSl2bLvY0cHOkiuAP9hHhbSmfFNbJ8Qyilk0ULgftXyfVBiOihilKIgJ0 kPF0dfFEIPlCWXFS5X6fNfRaj6jRLAGEVuVLfpjGYWG3ehNjso5Yd3QOBYfd4rZsQOMj 7aTDfb1ey8fWegg9L9TBfOCCrdP/dnwRVE+38x9wt/prxUCy60IIv4pSjMqZOdXbg2Li hgwBMSeSm6SuRq0ztkhO4+ZiOPeRwASdTHDM4qFldCd70qj5PYZaMsqraBapH2nXoVIe pYxA== X-Gm-Message-State: AOJu0YxqCbSI9F/8AD2aFqye5Lo1tCH7gv7TjgRfRimo/NnJcsM9hbjq pLiw0GCFvnK6zP61/XGms3MJ0D/D9unld/vEKeR8OfyhDjzilsyozIrwcCa/rv8wzG3iVCPsbgX 6FDa0r4BOlg== X-Google-Smtp-Source: AGHT+IFMPTsoGxUsumAtN3chcaukZ3C6wjkHWoIAeMwy/+KcTA62jn8U8xL2b6hSdyb9NeENKxSUsnW0kDQcVw== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a0d:d74c:0:b0:618:8e4b:f49d with SMTP id z73-20020a0dd74c000000b006188e4bf49dmr2701634ywd.4.1714998634160; Mon, 06 May 2024 05:30:34 -0700 (PDT) Date: Mon, 6 May 2024 12:30:32 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.45.0.rc1.225.g2a3ae87e7f-goog Message-ID: <20240506123032.3351895-1-edumazet@google.com> Subject: [PATCH net-next] mptcp: fix possible NULL dereferences From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , syzbot , Jason Xing , Matthieu Baerts X-Patchwork-Delegate: kuba@kernel.org subflow_add_reset_reason(skb, ...) can fail. We can not assume mptcp_get_ext(skb) always return a non NULL pointer. syzbot reported: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 0 PID: 5098 Comm: syz-executor132 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:subflow_v6_route_req+0x2c7/0x490 net/mptcp/subflow.c:388 Code: 8d 7b 07 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 0f b6 43 07 48 8d 1c c3 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 84 01 00 00 0f b6 5b 01 83 e3 0f 48 89 RSP: 0018:ffffc9000362eb68 EFLAGS: 00010206 RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888022039e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88807d961140 R08: ffffffff8b6cb76b R09: 1ffff1100fb2c230 R10: dffffc0000000000 R11: ffffed100fb2c231 R12: dffffc0000000000 R13: ffff888022bfe273 R14: ffff88802cf9cc80 R15: ffff88802ad5a700 FS: 0000555587ad2380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f420c3f9720 CR3: 0000000022bfc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_conn_request+0xf07/0x32c0 net/ipv4/tcp_input.c:7180 tcp_rcv_state_process+0x183c/0x4500 net/ipv4/tcp_input.c:6663 tcp_v6_do_rcv+0x8b2/0x1310 net/ipv6/tcp_ipv6.c:1673 tcp_v6_rcv+0x22b4/0x30b0 net/ipv6/tcp_ipv6.c:1910 ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5625 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5739 netif_receive_skb_internal net/core/dev.c:5825 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5885 tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1549 tun_get_user+0x2f35/0x4560 drivers/net/tun.c:2002 tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 3e140491dd80 ("mptcp: support rstreason for passive reset") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Jason Xing Cc: Matthieu Baerts (NGI0) Cc: Paolo Abeni Acked-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Reviewed-by: Jason Xing --- net/mptcp/subflow.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 97ec44d1df308f53e8ebabe6f77c8c86859b5a36..7208d824be353476496271e971ccafde1a47b959 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -287,6 +287,16 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req, } EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); +static enum sk_rst_reason mptcp_get_rst_reason(const struct sk_buff *skb) +{ + const struct mptcp_ext *mpext = mptcp_get_ext(skb); + + if (!mpext) + return SK_RST_REASON_NOT_SPECIFIED; + + return sk_rst_convert_mptcp_reason(mpext->reset_reason); +} + static struct dst_entry *subflow_v4_route_req(const struct sock *sk, struct sk_buff *skb, struct flowi *fl, @@ -308,13 +318,9 @@ static struct dst_entry *subflow_v4_route_req(const struct sock *sk, return dst; dst_release(dst); - if (!req->syncookie) { - struct mptcp_ext *mpext = mptcp_get_ext(skb); - enum sk_rst_reason reason; - - reason = sk_rst_convert_mptcp_reason(mpext->reset_reason); - tcp_request_sock_ops.send_reset(sk, skb, reason); - } + if (!req->syncookie) + tcp_request_sock_ops.send_reset(sk, skb, + mptcp_get_rst_reason(skb)); return NULL; } @@ -381,13 +387,9 @@ static struct dst_entry *subflow_v6_route_req(const struct sock *sk, return dst; dst_release(dst); - if (!req->syncookie) { - struct mptcp_ext *mpext = mptcp_get_ext(skb); - enum sk_rst_reason reason; - - reason = sk_rst_convert_mptcp_reason(mpext->reset_reason); - tcp6_request_sock_ops.send_reset(sk, skb, reason); - } + if (!req->syncookie) + tcp6_request_sock_ops.send_reset(sk, skb, + mptcp_get_rst_reason(skb)); return NULL; } #endif @@ -923,7 +925,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, tcp_rsk(req)->drop_req = true; inet_csk_prepare_for_destroy_sock(child); tcp_done(child); - reason = sk_rst_convert_mptcp_reason(mptcp_get_ext(skb)->reset_reason); + reason = mptcp_get_rst_reason(skb); req->rsk_ops->send_reset(sk, skb, reason); /* The last child reference will be released by the caller */