[PATCH net 0/8] Netfilter fixes for net

[PATCH net 0/8] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) Nicolas Dichtel updates MAINTAINERS file to add Netfilter IRC channel.

2) Skip non-IPv6 packets in nft_exthdr.

3) Skip non-TCP packets in nft_osf.

4) Skip non-TCP/UDP packets in nft_tproxy.

5) Memleak in hardware offload infrastructure when counters are used
   for first time in a rule.

6) The VLAN transfer routine must use FLOW_DISSECTOR_KEY_BASIC instead
   of FLOW_DISSECTOR_KEY_CONTROL. Moreover, make a more robust check
   for 802.1q and 802.1ad to restore simple matching on transport
   protocols.

7) Fix bogus EPERM when listing a ruleset when table ownership flag
   is set on.

8) Honor table ownership flag when table is referenced by handle.

Please, pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Thank you!

----------------------------------------------------------------

The following changes since commit a4f0377db1254373513b992ff31a351a7111f0fd:

  Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf (2021-06-15 15:26:07 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git HEAD

for you to fetch changes up to e31f072ffab0397a328b31a9589dcf9733dc9c72:

  netfilter: nf_tables: do not allow to delete table with owner by handle (2021-06-22 12:15:05 +0200)

----------------------------------------------------------------
Nicolas Dichtel (1):
      MAINTAINERS: netfilter: add irc channel

Pablo Neira Ayuso (7):
      netfilter: nft_exthdr: check for IPv6 packet before further processing
      netfilter: nft_osf: check for TCP packet before further processing
      netfilter: nft_tproxy: restrict support to TCP and UDP transport protocols
      netfilter: nf_tables: memleak in hw offload abort path
      netfilter: nf_tables_offload: check FLOW_DISSECTOR_KEY_BASIC in VLAN transfer logic
      netfilter: nf_tables: skip netlink portID validation if zero
      netfilter: nf_tables: do not allow to delete table with owner by handle

 MAINTAINERS                       |  1 +
 net/netfilter/nf_tables_api.c     | 65 ++++++++++++++++++++++++---------------
 net/netfilter/nf_tables_offload.c | 34 +++++---------------
 net/netfilter/nft_exthdr.c        |  3 ++
 net/netfilter/nft_osf.c           |  5 +++
 net/netfilter/nft_tproxy.c        |  9 +++++-
 6 files changed, 65 insertions(+), 52 deletions(-)

[PATCH net 1/8] MAINTAINERS: netfilter: add irc channel

[Pablo Neira Ayuso]

From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

The community #netfilter IRC channel is now live on the libera.chat network
(https://libera.chat/).

CC: Arturo Borrero Gonzalez <arturo@netfilter.org>
Link: https://marc.info/?l=netfilter&m=162210948632717
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index bfb3d0931cba..f3d44262d16e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12657,6 +12657,7 @@ W:	http://www.netfilter.org/
 W:	http://www.iptables.org/
 W:	http://www.nftables.org/
 Q:	http://patchwork.ozlabs.org/project/netfilter-devel/list/
+C:	irc://irc.libera.chat/netfilter
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git
 F:	include/linux/netfilter*
-- 
2.30.2

Re: [PATCH net 1/8] MAINTAINERS: netfilter: add irc channel

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Tue, 22 Jun 2021 23:59:54 +0200 you wrote:
> From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> 
> The community #netfilter IRC channel is now live on the libera.chat network
> (https://libera.chat/).
> 
> CC: Arturo Borrero Gonzalez <arturo@netfilter.org>
> Link: https://marc.info/?l=netfilter&m=162210948632717
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> 
> [...]

Here is the summary with links:
  - [net,1/8] MAINTAINERS: netfilter: add irc channel
    https://git.kernel.org/netdev/net/c/8744365e2584
  - [net,2/8] netfilter: nft_exthdr: check for IPv6 packet before further processing
    https://git.kernel.org/netdev/net/c/cdd73cc545c0
  - [net,3/8] netfilter: nft_osf: check for TCP packet before further processing
    https://git.kernel.org/netdev/net/c/8f518d43f89a
  - [net,4/8] netfilter: nft_tproxy: restrict support to TCP and UDP transport protocols
    https://git.kernel.org/netdev/net/c/52f0f4e178c7
  - [net,5/8] netfilter: nf_tables: memleak in hw offload abort path
    https://git.kernel.org/netdev/net/c/3c5e44622011
  - [net,6/8] netfilter: nf_tables_offload: check FLOW_DISSECTOR_KEY_BASIC in VLAN transfer logic
    https://git.kernel.org/netdev/net/c/ea45fdf82cc9
  - [net,7/8] netfilter: nf_tables: skip netlink portID validation if zero
    https://git.kernel.org/netdev/net/c/534799097a77
  - [net,8/8] netfilter: nf_tables: do not allow to delete table with owner by handle
    https://git.kernel.org/netdev/net/c/e31f072ffab0

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

[PATCH net 2/8] netfilter: nft_exthdr: check for IPv6 packet before further processing

[Pablo Neira Ayuso]

ipv6_find_hdr() does not validate that this is an IPv6 packet. Add a
sanity check for calling ipv6_find_hdr() to make sure an IPv6 packet
is passed for parsing.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_exthdr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
index f64f0017e9a5..670dd146fb2b 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -42,6 +42,9 @@ static void nft_exthdr_ipv6_eval(const struct nft_expr *expr,
 	unsigned int offset = 0;
 	int err;
 
+	if (pkt->skb->protocol != htons(ETH_P_IPV6))
+		goto err;
+
 	err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
 	if (priv->flags & NFT_EXTHDR_F_PRESENT) {
 		nft_reg_store8(dest, err >= 0);
-- 
2.30.2

[PATCH net 3/8] netfilter: nft_osf: check for TCP packet before further processing

[Pablo Neira Ayuso]

The osf expression only supports for TCP packets, add a upfront sanity
check to skip packet parsing if this is not a TCP packet.

Fixes: b96af92d6eaf ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_osf.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c
index ac61f708b82d..d82677e83400 100644
--- a/net/netfilter/nft_osf.c
+++ b/net/netfilter/nft_osf.c
@@ -28,6 +28,11 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs,
 	struct nf_osf_data data;
 	struct tcphdr _tcph;
 
+	if (pkt->tprot != IPPROTO_TCP) {
+		regs->verdict.code = NFT_BREAK;
+		return;
+	}
+
 	tcp = skb_header_pointer(skb, ip_hdrlen(skb),
 				 sizeof(struct tcphdr), &_tcph);
 	if (!tcp) {
-- 
2.30.2

[PATCH net 4/8] netfilter: nft_tproxy: restrict support to TCP and UDP transport protocols

[Pablo Neira Ayuso]

Add unfront check for TCP and UDP packets before performing further
processing.

Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_tproxy.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_tproxy.c b/net/netfilter/nft_tproxy.c
index accef672088c..5cb4d575d47f 100644
--- a/net/netfilter/nft_tproxy.c
+++ b/net/netfilter/nft_tproxy.c
@@ -30,6 +30,12 @@ static void nft_tproxy_eval_v4(const struct nft_expr *expr,
 	__be16 tport = 0;
 	struct sock *sk;
 
+	if (pkt->tprot != IPPROTO_TCP &&
+	    pkt->tprot != IPPROTO_UDP) {
+		regs->verdict.code = NFT_BREAK;
+		return;
+	}
+
 	hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
 	if (!hp) {
 		regs->verdict.code = NFT_BREAK;
@@ -91,7 +97,8 @@ static void nft_tproxy_eval_v6(const struct nft_expr *expr,
 
 	memset(&taddr, 0, sizeof(taddr));
 
-	if (!pkt->tprot_set) {
+	if (pkt->tprot != IPPROTO_TCP &&
+	    pkt->tprot != IPPROTO_UDP) {
 		regs->verdict.code = NFT_BREAK;
 		return;
 	}
-- 
2.30.2

[PATCH net 5/8] netfilter: nf_tables: memleak in hw offload abort path

[Pablo Neira Ayuso]

Release flow from the abort path, this is easy to reproduce since
b72920f6e4a9 ("netfilter: nftables: counter hardware offload support").
If the preparation phase fails, then the abort path is exercised without
releasing the flow rule object.

unreferenced object 0xffff8881f0fa7700 (size 128):
  comm "nft", pid 1335, jiffies 4294931120 (age 4163.740s)
  hex dump (first 32 bytes):
    08 e4 de 13 82 88 ff ff 98 e4 de 13 82 88 ff ff  ................
    48 e4 de 13 82 88 ff ff 01 00 00 00 00 00 00 00  H...............
  backtrace:
    [<00000000634547e7>] flow_rule_alloc+0x26/0x80
    [<00000000c8426156>] nft_flow_rule_create+0xc9/0x3f0 [nf_tables]
    [<0000000075ff8e46>] nf_tables_newrule+0xc79/0x10a0 [nf_tables]
    [<00000000ba65e40e>] nfnetlink_rcv_batch+0xaac/0xf90 [nfnetlink]
    [<00000000505c614a>] nfnetlink_rcv+0x1bb/0x1f0 [nfnetlink]
    [<00000000eb78e1fe>] netlink_unicast+0x34b/0x480
    [<00000000a8f72c94>] netlink_sendmsg+0x3af/0x690
    [<000000009cb1ddf4>] sock_sendmsg+0x96/0xa0
    [<0000000039d06e44>] ____sys_sendmsg+0x3fe/0x440
    [<00000000137e82ca>] ___sys_sendmsg+0xd8/0x140
    [<000000000c6bf6a6>] __sys_sendmsg+0xb3/0x130
    [<0000000043bd6268>] do_syscall_64+0x40/0xb0
    [<00000000afdebc2d>] entry_SYSCALL_64_after_hwframe+0x44/0xae

Remove flow rule release from the offload commit path, otherwise error
from the offload commit phase might trigger a double-free due to the
execution of the abort_offload -> abort. After this patch, the abort
path takes care of releasing the flow rule.

This fix also needs to move the nft_flow_rule_create() call before the
transaction object is added otherwise the abort path might find a NULL
pointer to the flow rule object for the NFT_CHAIN_HW_OFFLOAD case.

While at it, rename BASIC-like goto tags to slightly more meaningful
names rather than adding a new "err3" tag.

Fixes: 63b48c73ff56 ("netfilter: nf_tables_offload: undo updates if transaction fails")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c     | 51 +++++++++++++++++++------------
 net/netfilter/nf_tables_offload.c | 17 -----------
 2 files changed, 31 insertions(+), 37 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index bf4d6ec9fc55..ca9ec8721e6c 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3243,9 +3243,9 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 	u8 genmask = nft_genmask_next(info->net);
 	struct nft_rule *rule, *old_rule = NULL;
 	struct nft_expr_info *expr_info = NULL;
+	struct nft_flow_rule *flow = NULL;
 	int family = nfmsg->nfgen_family;
 	struct net *net = info->net;
-	struct nft_flow_rule *flow;
 	struct nft_userdata *udata;
 	struct nft_table *table;
 	struct nft_chain *chain;
@@ -3340,13 +3340,13 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 		nla_for_each_nested(tmp, nla[NFTA_RULE_EXPRESSIONS], rem) {
 			err = -EINVAL;
 			if (nla_type(tmp) != NFTA_LIST_ELEM)
-				goto err1;
+				goto err_release_expr;
 			if (n == NFT_RULE_MAXEXPRS)
-				goto err1;
+				goto err_release_expr;
 			err = nf_tables_expr_parse(&ctx, tmp, &expr_info[n]);
 			if (err < 0) {
 				NL_SET_BAD_ATTR(extack, tmp);
-				goto err1;
+				goto err_release_expr;
 			}
 			size += expr_info[n].ops->size;
 			n++;
@@ -3355,7 +3355,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 	/* Check for overflow of dlen field */
 	err = -EFBIG;
 	if (size >= 1 << 12)
-		goto err1;
+		goto err_release_expr;
 
 	if (nla[NFTA_RULE_USERDATA]) {
 		ulen = nla_len(nla[NFTA_RULE_USERDATA]);
@@ -3366,7 +3366,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 	err = -ENOMEM;
 	rule = kzalloc(sizeof(*rule) + size + usize, GFP_KERNEL);
 	if (rule == NULL)
-		goto err1;
+		goto err_release_expr;
 
 	nft_activate_next(net, rule);
 
@@ -3385,7 +3385,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 		err = nf_tables_newexpr(&ctx, &expr_info[i], expr);
 		if (err < 0) {
 			NL_SET_BAD_ATTR(extack, expr_info[i].attr);
-			goto err2;
+			goto err_release_rule;
 		}
 
 		if (expr_info[i].ops->validate)
@@ -3395,16 +3395,24 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 		expr = nft_expr_next(expr);
 	}
 
+	if (chain->flags & NFT_CHAIN_HW_OFFLOAD) {
+		flow = nft_flow_rule_create(net, rule);
+		if (IS_ERR(flow)) {
+			err = PTR_ERR(flow);
+			goto err_release_rule;
+		}
+	}
+
 	if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
 		trans = nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule);
 		if (trans == NULL) {
 			err = -ENOMEM;
-			goto err2;
+			goto err_destroy_flow_rule;
 		}
 		err = nft_delrule(&ctx, old_rule);
 		if (err < 0) {
 			nft_trans_destroy(trans);
-			goto err2;
+			goto err_destroy_flow_rule;
 		}
 
 		list_add_tail_rcu(&rule->list, &old_rule->list);
@@ -3412,7 +3420,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 		trans = nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule);
 		if (!trans) {
 			err = -ENOMEM;
-			goto err2;
+			goto err_destroy_flow_rule;
 		}
 
 		if (info->nlh->nlmsg_flags & NLM_F_APPEND) {
@@ -3430,21 +3438,19 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 	kvfree(expr_info);
 	chain->use++;
 
+	if (flow)
+		nft_trans_flow_rule(trans) = flow;
+
 	if (nft_net->validate_state == NFT_VALIDATE_DO)
 		return nft_table_validate(net, table);
 
-	if (chain->flags & NFT_CHAIN_HW_OFFLOAD) {
-		flow = nft_flow_rule_create(net, rule);
-		if (IS_ERR(flow))
-			return PTR_ERR(flow);
-
-		nft_trans_flow_rule(trans) = flow;
-	}
-
 	return 0;
-err2:
+
+err_destroy_flow_rule:
+	nft_flow_rule_destroy(flow);
+err_release_rule:
 	nf_tables_rule_release(&ctx, rule);
-err1:
+err_release_expr:
 	for (i = 0; i < n; i++) {
 		if (expr_info[i].ops) {
 			module_put(expr_info[i].ops->type->owner);
@@ -8839,11 +8845,16 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 			nft_rule_expr_deactivate(&trans->ctx,
 						 nft_trans_rule(trans),
 						 NFT_TRANS_ABORT);
+			if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD)
+				nft_flow_rule_destroy(nft_trans_flow_rule(trans));
 			break;
 		case NFT_MSG_DELRULE:
 			trans->ctx.chain->use++;
 			nft_clear(trans->ctx.net, nft_trans_rule(trans));
 			nft_rule_expr_activate(&trans->ctx, nft_trans_rule(trans));
+			if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD)
+				nft_flow_rule_destroy(nft_trans_flow_rule(trans));
+
 			nft_trans_destroy(trans);
 			break;
 		case NFT_MSG_NEWSET:
diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index a48c5fd53a80..ec701b84844f 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -594,23 +594,6 @@ int nft_flow_rule_offload_commit(struct net *net)
 		}
 	}
 
-	list_for_each_entry(trans, &nft_net->commit_list, list) {
-		if (trans->ctx.family != NFPROTO_NETDEV)
-			continue;
-
-		switch (trans->msg_type) {
-		case NFT_MSG_NEWRULE:
-		case NFT_MSG_DELRULE:
-			if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
-				continue;
-
-			nft_flow_rule_destroy(nft_trans_flow_rule(trans));
-			break;
-		default:
-			break;
-		}
-	}
-
 	return err;
 }
 
-- 
2.30.2

[PATCH net 6/8] netfilter: nf_tables_offload: check FLOW_DISSECTOR_KEY_BASIC in VLAN transfer logic

[Pablo Neira Ayuso]

The VLAN transfer logic should actually check for
FLOW_DISSECTOR_KEY_BASIC, not FLOW_DISSECTOR_KEY_CONTROL. Moreover, do
not fallback to case 2) .n_proto is set to 802.1q or 802.1ad, if
FLOW_DISSECTOR_KEY_BASIC is unset.

Fixes: 783003f3bb8a ("netfilter: nftables_offload: special ethertype handling for VLAN")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_offload.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index ec701b84844f..b58d73a96523 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -54,15 +54,10 @@ static void nft_flow_rule_transfer_vlan(struct nft_offload_ctx *ctx,
 					struct nft_flow_rule *flow)
 {
 	struct nft_flow_match *match = &flow->match;
-	struct nft_offload_ethertype ethertype;
-
-	if (match->dissector.used_keys & BIT(FLOW_DISSECTOR_KEY_CONTROL) &&
-	    match->key.basic.n_proto != htons(ETH_P_8021Q) &&
-	    match->key.basic.n_proto != htons(ETH_P_8021AD))
-		return;
-
-	ethertype.value = match->key.basic.n_proto;
-	ethertype.mask = match->mask.basic.n_proto;
+	struct nft_offload_ethertype ethertype = {
+		.value	= match->key.basic.n_proto,
+		.mask	= match->mask.basic.n_proto,
+	};
 
 	if (match->dissector.used_keys & BIT(FLOW_DISSECTOR_KEY_VLAN) &&
 	    (match->key.vlan.vlan_tpid == htons(ETH_P_8021Q) ||
@@ -76,7 +71,9 @@ static void nft_flow_rule_transfer_vlan(struct nft_offload_ctx *ctx,
 		match->dissector.offset[FLOW_DISSECTOR_KEY_CVLAN] =
 			offsetof(struct nft_flow_key, cvlan);
 		match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_CVLAN);
-	} else {
+	} else if (match->dissector.used_keys & BIT(FLOW_DISSECTOR_KEY_BASIC) &&
+		   (match->key.basic.n_proto == htons(ETH_P_8021Q) ||
+		    match->key.basic.n_proto == htons(ETH_P_8021AD))) {
 		match->key.basic.n_proto = match->key.vlan.vlan_tpid;
 		match->mask.basic.n_proto = match->mask.vlan.vlan_tpid;
 		match->key.vlan.vlan_tpid = ethertype.value;
-- 
2.30.2

[PATCH net 7/8] netfilter: nf_tables: skip netlink portID validation if zero

[Pablo Neira Ayuso]

nft_table_lookup() allows us to obtain the table object by the name and
the family. The netlink portID validation needs to be skipped for the
dump path, since the ownership only applies to commands to update the
given table. Skip validation if the specified netlink PortID is zero
when calling nft_table_lookup().

Fixes: 6001a930ce03 ("netfilter: nftables: introduce table ownership")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ca9ec8721e6c..1d62b1a83299 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -571,7 +571,7 @@ static struct nft_table *nft_table_lookup(const struct net *net,
 		    table->family == family &&
 		    nft_active_genmask(table, genmask)) {
 			if (nft_table_has_owner(table) &&
-			    table->nlpid != nlpid)
+			    nlpid && table->nlpid != nlpid)
 				return ERR_PTR(-EPERM);
 
 			return table;
-- 
2.30.2

[PATCH net 8/8] netfilter: nf_tables: do not allow to delete table with owner by handle

[Pablo Neira Ayuso]

nft_table_lookup_byhandle() also needs to validate the netlink PortID
owner when deleting a table by handle.

Fixes: 6001a930ce03 ("netfilter: nftables: introduce table ownership")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 1d62b1a83299..fcb15b8904e8 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -583,7 +583,7 @@ static struct nft_table *nft_table_lookup(const struct net *net,
 
 static struct nft_table *nft_table_lookup_byhandle(const struct net *net,
 						   const struct nlattr *nla,
-						   u8 genmask)
+						   u8 genmask, u32 nlpid)
 {
 	struct nftables_pernet *nft_net;
 	struct nft_table *table;
@@ -591,8 +591,13 @@ static struct nft_table *nft_table_lookup_byhandle(const struct net *net,
 	nft_net = nft_pernet(net);
 	list_for_each_entry(table, &nft_net->tables, list) {
 		if (be64_to_cpu(nla_get_be64(nla)) == table->handle &&
-		    nft_active_genmask(table, genmask))
+		    nft_active_genmask(table, genmask)) {
+			if (nft_table_has_owner(table) &&
+			    nlpid && table->nlpid != nlpid)
+				return ERR_PTR(-EPERM);
+
 			return table;
+		}
 	}
 
 	return ERR_PTR(-ENOENT);
@@ -1279,7 +1284,8 @@ static int nf_tables_deltable(struct sk_buff *skb, const struct nfnl_info *info,
 
 	if (nla[NFTA_TABLE_HANDLE]) {
 		attr = nla[NFTA_TABLE_HANDLE];
-		table = nft_table_lookup_byhandle(net, attr, genmask);
+		table = nft_table_lookup_byhandle(net, attr, genmask,
+						  NETLINK_CB(skb).portid);
 	} else {
 		attr = nla[NFTA_TABLE_NAME];
 		table = nft_table_lookup(net, attr, family, genmask,
-- 
2.30.2

Re: [PATCH net 0/8] Netfilter fixes for net

[David Miller]

[davem@localhost net]$ git pull --no-ff git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git
From git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
 * branch                      HEAD       -> FETCH_HEAD
Already up to date.
[davem@localhost net]$

???

Re: [PATCH net 0/8] Netfilter fixes for net

[Pablo Neira Ayuso]

On Tue, Jun 22, 2021 at 03:41:12PM -0700, David Miller wrote:
> 
> [davem@localhost net]$ git pull --no-ff git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git
> From git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
>  * branch                      HEAD       -> FETCH_HEAD
> Already up to date.
> [davem@localhost net]$
> 
> ???

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