From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A179B1DE8B0; Tue, 8 Oct 2024 12:14:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728389656; cv=none; b=PUq/ZwhEsiYcB99igawuQQKACFfghWllYCjWriNcgScR5If1saoPff9wDKUwpwrH3tSS+C2ky0GRNCMJ0KthM6d323f5rK7TMw5aKb7kwluCe65Tm9NWdGitC7iAeF3IOj7FCJ6kkIfQGjBL38tUGGxNVykJLTRIsYP1WwMElmk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728389656; c=relaxed/simple; bh=7/c5pF9OzNDXme6kktKn4N+xDdwtqw2ENJvgDsFxhlA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nur2UGQUx3ktprDwwO9cce60/Z2r4+f/64Js2DsIv/MfARFm8VZON3GFPtOPqx4FQxTL3bJ4rxu2M72xbcE/OxGeMLZFox4J6s31mh/uqb3NARsBvM56IO9qw69DSVBIh4A70LdeADyKfh9IXO4mjNFh1yUZyyQGAsonWxYTjeQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rDNsGgFw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rDNsGgFw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11440C4CEC7; Tue, 8 Oct 2024 12:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728389656; bh=7/c5pF9OzNDXme6kktKn4N+xDdwtqw2ENJvgDsFxhlA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rDNsGgFwo8aY0/wDfQ00iwYcat/5WyMu9He0gPYmhtkK7PgbR2rcRQOXNij5qROE0 0aif4w84eVHd8NEohhtDn4uzcPgMyKchmJHWMyotC8ENPzmi7SPnvHY6jYkKWkeyoQ 3ZOK/epRmCxEVbiT0n4M6zW60pTTdSLlDjWpcG5Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot , Eric Dumazet , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 6.10 026/482] netfilter: nf_tables: prevent nf_skb_duplicated corruption Date: Tue, 8 Oct 2024 14:01:29 +0200 Message-ID: <20241008115649.329531928@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115648.280954295@linuxfoundation.org> References: <20241008115648.280954295@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 92ceba94de6fb4cee2bf40b485979c342f44a492 ] syzbot found that nf_dup_ipv4() or nf_dup_ipv6() could write per-cpu variable nf_skb_duplicated in an unsafe way [1]. Disabling preemption as hinted by the splat is not enough, we have to disable soft interrupts as well. [1] BUG: using __this_cpu_write() in preemptible [00000000] code: syz.4.282/6316 caller is nf_dup_ipv4+0x651/0x8f0 net/ipv4/netfilter/nf_dup_ipv4.c:87 CPU: 0 UID: 0 PID: 6316 Comm: syz.4.282 Not tainted 6.11.0-rc7-syzkaller-00104-g7052622fccb1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_preemption_disabled+0x10e/0x120 lib/smp_processor_id.c:49 nf_dup_ipv4+0x651/0x8f0 net/ipv4/netfilter/nf_dup_ipv4.c:87 nft_dup_ipv4_eval+0x1db/0x300 net/ipv4/netfilter/nft_dup_ipv4.c:30 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x202/0x320 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook+0x2c4/0x450 include/linux/netfilter.h:269 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip_output+0x185/0x230 net/ipv4/ip_output.c:433 ip_local_out net/ipv4/ip_output.c:129 [inline] ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1495 udp_send_skb+0xacf/0x1650 net/ipv4/udp.c:981 udp_sendmsg+0x1c21/0x2a60 net/ipv4/udp.c:1269 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ce4f7def9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4ce5d4a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f4ce5135f80 RCX: 00007f4ce4f7def9 RDX: 0000000000000001 RSI: 0000000020005d40 RDI: 0000000000000006 RBP: 00007f4ce4ff0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4ce5135f80 R15: 00007ffd4cbc6d68 Fixes: d877f07112f1 ("netfilter: nf_tables: add nft_dup expression") Reported-by: syzbot Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/ipv4/netfilter/nf_dup_ipv4.c | 7 +++++-- net/ipv6/netfilter/nf_dup_ipv6.c | 7 +++++-- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/net/ipv4/netfilter/nf_dup_ipv4.c b/net/ipv4/netfilter/nf_dup_ipv4.c index 6cc5743c553a0..9a21175693db5 100644 --- a/net/ipv4/netfilter/nf_dup_ipv4.c +++ b/net/ipv4/netfilter/nf_dup_ipv4.c @@ -52,8 +52,9 @@ void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum, { struct iphdr *iph; + local_bh_disable(); if (this_cpu_read(nf_skb_duplicated)) - return; + goto out; /* * Copy the skb, and route the copy. Will later return %XT_CONTINUE for * the original skb, which should continue on its way as if nothing has @@ -61,7 +62,7 @@ void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum, */ skb = pskb_copy(skb, GFP_ATOMIC); if (skb == NULL) - return; + goto out; #if IS_ENABLED(CONFIG_NF_CONNTRACK) /* Avoid counting cloned packets towards the original connection. */ @@ -90,6 +91,8 @@ void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum, } else { kfree_skb(skb); } +out: + local_bh_enable(); } EXPORT_SYMBOL_GPL(nf_dup_ipv4); diff --git a/net/ipv6/netfilter/nf_dup_ipv6.c b/net/ipv6/netfilter/nf_dup_ipv6.c index a0a2de30be3e7..0c39c77fe8a8a 100644 --- a/net/ipv6/netfilter/nf_dup_ipv6.c +++ b/net/ipv6/netfilter/nf_dup_ipv6.c @@ -47,11 +47,12 @@ static bool nf_dup_ipv6_route(struct net *net, struct sk_buff *skb, void nf_dup_ipv6(struct net *net, struct sk_buff *skb, unsigned int hooknum, const struct in6_addr *gw, int oif) { + local_bh_disable(); if (this_cpu_read(nf_skb_duplicated)) - return; + goto out; skb = pskb_copy(skb, GFP_ATOMIC); if (skb == NULL) - return; + goto out; #if IS_ENABLED(CONFIG_NF_CONNTRACK) nf_reset_ct(skb); @@ -69,6 +70,8 @@ void nf_dup_ipv6(struct net *net, struct sk_buff *skb, unsigned int hooknum, } else { kfree_skb(skb); } +out: + local_bh_enable(); } EXPORT_SYMBOL_GPL(nf_dup_ipv6); -- 2.43.0