From patchwork Wed Jul 31 21:30:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 13749246 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AE2C145957; Wed, 31 Jul 2024 21:37:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.188.207 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722461880; cv=none; b=Q9WLZUHCJmTDyt13YmW3yBCnRxdE4AE0cE96QhS9jGCwmClS3HltKif4hlVM/JDkCgE5Ds4nykSH3CX/a/S5qoyL2vxLtET0OMCQVCj8O5/wGf2ddcTI5HBI40+zi5SnFG2zN9jHto9XkwUM9V+CQDlBYBhbHhcX3Ja+nk5z21c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722461880; c=relaxed/simple; bh=bf0SKKwx+Qb2oj+vG9u4bxyroXezTYc9cUzgyC8a26g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fGUwcU0ORpHmrseqsW2uHZhg1fcmk12dABuEiZxxcRhZkmXw2gs1MuN9BJ/Q1/vCTmBqiyUHhlA0ia5rcwcK8s1ETR2qd4gl37JtPGHUh+p1ZK3FxoP33QbUSUbzRXU4uPKUTMPPu8uoyiBCR7kPd0fDCPeWxV30rwDYrf6CV9Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; arc=none smtp.client-ip=217.70.188.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, fw@strlen.de Subject: [PATCH net 1/2] netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init(). Date: Wed, 31 Jul 2024 23:30:45 +0200 Message-Id: <20240731213046.6194-2-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240731213046.6194-1-pablo@netfilter.org> References: <20240731213046.6194-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Kuniyuki Iwashima We had a report that iptables-restore sometimes triggered null-ptr-deref at boot time. [0] The problem is that iptable_nat_table_init() is exposed to user space before the kernel fully initialises netns. In the small race window, a user could call iptable_nat_table_init() that accesses net_generic(net, iptable_nat_net_id), which is available only after registering iptable_nat_net_ops. Let's call register_pernet_subsys() before xt_register_template(). [0]: bpfilter: Loaded bpfilter_umh pid 11702 Started bpfilter BUG: kernel NULL pointer dereference, address: 0000000000000013 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page PGD 0 P4D 0 PREEMPT SMP NOPTI CPU: 2 PID: 11879 Comm: iptables-restor Not tainted 6.1.92-99.174.amzn2023.x86_64 #1 Hardware name: Amazon EC2 c6i.4xlarge/, BIOS 1.0 10/16/2017 RIP: 0010:iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat Code: 10 4c 89 f6 48 89 ef e8 0b 19 bb ff 41 89 c4 85 c0 75 38 41 83 c7 01 49 83 c6 28 41 83 ff 04 75 dc 48 8b 44 24 08 48 8b 0c 24 <48> 89 08 4c 89 ef e8 a2 3b a2 cf 48 83 c4 10 44 89 e0 5b 5d 41 5c RSP: 0018:ffffbef902843cd0 EFLAGS: 00010246 RAX: 0000000000000013 RBX: ffff9f4b052caa20 RCX: ffff9f4b20988d80 RDX: 0000000000000000 RSI: 0000000000000064 RDI: ffffffffc04201c0 RBP: ffff9f4b29394000 R08: ffff9f4b07f77258 R09: ffff9f4b07f77240 R10: 0000000000000000 R11: ffff9f4b09635388 R12: 0000000000000000 R13: ffff9f4b1a3c6c00 R14: ffff9f4b20988e20 R15: 0000000000000004 FS: 00007f6284340000(0000) GS:ffff9f51fe280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000013 CR3: 00000001d10a6005 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259) ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259) ? xt_find_table_lock (net/netfilter/x_tables.c:1259) ? __die_body.cold (arch/x86/kernel/dumpstack.c:478 arch/x86/kernel/dumpstack.c:420) ? page_fault_oops (arch/x86/mm/fault.c:727) ? exc_page_fault (./arch/x86/include/asm/irqflags.h:40 ./arch/x86/include/asm/irqflags.h:75 arch/x86/mm/fault.c:1470 arch/x86/mm/fault.c:1518) ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:570) ? iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat xt_find_table_lock (net/netfilter/x_tables.c:1259) xt_request_find_table_lock (net/netfilter/x_tables.c:1287) get_info (net/ipv4/netfilter/ip_tables.c:965) ? security_capable (security/security.c:809 (discriminator 13)) ? ns_capable (kernel/capability.c:376 kernel/capability.c:397) ? do_ipt_get_ctl (net/ipv4/netfilter/ip_tables.c:1656) ? bpfilter_send_req (net/bpfilter/bpfilter_kern.c:52) bpfilter nf_getsockopt (net/netfilter/nf_sockopt.c:116) ip_getsockopt (net/ipv4/ip_sockglue.c:1827) __sys_getsockopt (net/socket.c:2327) __x64_sys_getsockopt (net/socket.c:2342 net/socket.c:2339 net/socket.c:2339) do_syscall_64 (arch/x86/entry/common.c:51 arch/x86/entry/common.c:81) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) RIP: 0033:0x7f62844685ee Code: 48 8b 0d 45 28 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 09 RSP: 002b:00007ffd1f83d638 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffd1f83d680 RCX: 00007f62844685ee RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000004 R08: 00007ffd1f83d670 R09: 0000558798ffa2a0 R10: 00007ffd1f83d680 R11: 0000000000000246 R12: 00007ffd1f83e3b2 R13: 00007f628455baa0 R14: 00007ffd1f83d7b0 R15: 00007f628457a008 Modules linked in: iptable_nat(+) bpfilter rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache veth xt_state xt_connmark xt_nat xt_statistic xt_MASQUERADE xt_mark xt_addrtype ipt_REJECT nf_reject_ipv4 nft_chain_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment nft_compat nf_tables nfnetlink overlay nls_ascii nls_cp437 vfat fat ghash_clmulni_intel aesni_intel ena crypto_simd ptp cryptd i8042 pps_core serio button sunrpc sch_fq_codel configfs loop dm_mod fuse dax dmi_sysfs crc32_pclmul crc32c_intel efivarfs CR2: 0000000000000013 Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default") Reported-by: Takahiro Kawahara Signed-off-by: Kuniyuki Iwashima Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/iptable_nat.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c index 4d42d0756fd7..a5db7c67d61b 100644 --- a/net/ipv4/netfilter/iptable_nat.c +++ b/net/ipv4/netfilter/iptable_nat.c @@ -145,25 +145,27 @@ static struct pernet_operations iptable_nat_net_ops = { static int __init iptable_nat_init(void) { - int ret = xt_register_template(&nf_nat_ipv4_table, - iptable_nat_table_init); + int ret; + /* net->gen->ptr[iptable_nat_net_id] must be allocated + * before calling iptable_nat_table_init(). + */ + ret = register_pernet_subsys(&iptable_nat_net_ops); if (ret < 0) return ret; - ret = register_pernet_subsys(&iptable_nat_net_ops); - if (ret < 0) { - xt_unregister_template(&nf_nat_ipv4_table); - return ret; - } + ret = xt_register_template(&nf_nat_ipv4_table, + iptable_nat_table_init); + if (ret < 0) + unregister_pernet_subsys(&iptable_nat_net_ops); return ret; } static void __exit iptable_nat_exit(void) { - unregister_pernet_subsys(&iptable_nat_net_ops); xt_unregister_template(&nf_nat_ipv4_table); + unregister_pernet_subsys(&iptable_nat_net_ops); } module_init(iptable_nat_init); From patchwork Wed Jul 31 21:30:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 13749247 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AE28B3A1B5; 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dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, fw@strlen.de Subject: [PATCH net 2/2] netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init(). Date: Wed, 31 Jul 2024 23:30:46 +0200 Message-Id: <20240731213046.6194-3-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240731213046.6194-1-pablo@netfilter.org> References: <20240731213046.6194-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Kuniyuki Iwashima ip6table_nat_table_init() accesses net->gen->ptr[ip6table_nat_net_ops.id], but the function is exposed to user space before the entry is allocated via register_pernet_subsys(). Let's call register_pernet_subsys() before xt_register_template(). Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6table_nat.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c index 52cf104e3478..e119d4f090cc 100644 --- a/net/ipv6/netfilter/ip6table_nat.c +++ b/net/ipv6/netfilter/ip6table_nat.c @@ -147,23 +147,27 @@ static struct pernet_operations ip6table_nat_net_ops = { static int __init ip6table_nat_init(void) { - int ret = xt_register_template(&nf_nat_ipv6_table, - ip6table_nat_table_init); + int ret; + /* net->gen->ptr[ip6table_nat_net_id] must be allocated + * before calling ip6t_nat_register_lookups(). + */ + ret = register_pernet_subsys(&ip6table_nat_net_ops); if (ret < 0) return ret; - ret = register_pernet_subsys(&ip6table_nat_net_ops); + ret = xt_register_template(&nf_nat_ipv6_table, + ip6table_nat_table_init); if (ret) - xt_unregister_template(&nf_nat_ipv6_table); + unregister_pernet_subsys(&ip6table_nat_net_ops); return ret; } static void __exit ip6table_nat_exit(void) { - unregister_pernet_subsys(&ip6table_nat_net_ops); xt_unregister_template(&nf_nat_ipv6_table); + unregister_pernet_subsys(&ip6table_nat_net_ops); } module_init(ip6table_nat_init);