diff mbox series

[net,1/2] netfilter: nft_ct: skip expectations for confirmed conntrack

Message ID 20210602124430.10863-2-pablo@netfilter.org (mailing list archive)
State Accepted
Commit 1710eb913bdcda3917f44d383c32de6bdabfc836
Delegated to: Netdev Maintainers
Headers show
Series [net,1/2] netfilter: nft_ct: skip expectations for confirmed conntrack | expand

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netdev/build_32bit success Errors and warnings before: 2 this patch: 2
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
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Commit Message

Pablo Neira Ayuso June 2, 2021, 12:44 p.m. UTC
nft_ct_expect_obj_eval() calls nf_ct_ext_add() for a confirmed
conntrack entry. However, nf_ct_ext_add() can only be called for
!nf_ct_is_confirmed().

[ 1825.349056] WARNING: CPU: 0 PID: 1279 at net/netfilter/nf_conntrack_extend.c:48 nf_ct_xt_add+0x18e/0x1a0 [nf_conntrack]
[ 1825.351391] RIP: 0010:nf_ct_ext_add+0x18e/0x1a0 [nf_conntrack]
[ 1825.351493] Code: 41 5c 41 5d 41 5e 41 5f c3 41 bc 0a 00 00 00 e9 15 ff ff ff ba 09 00 00 00 31 f6 4c 89 ff e8 69 6c 3d e9 eb 96 45 31 ed eb cd <0f> 0b e9 b1 fe ff ff e8 86 79 14 e9 eb bf 0f 1f 40 00 0f 1f 44 00
[ 1825.351721] RSP: 0018:ffffc90002e1f1e8 EFLAGS: 00010202
[ 1825.351790] RAX: 000000000000000e RBX: ffff88814f5783c0 RCX: ffffffffc0e4f887
[ 1825.351881] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88814f578440
[ 1825.351971] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88814f578447
[ 1825.352060] R10: ffffed1029eaf088 R11: 0000000000000001 R12: ffff88814f578440
[ 1825.352150] R13: ffff8882053f3a00 R14: 0000000000000000 R15: 0000000000000a20
[ 1825.352240] FS:  00007f992261c900(0000) GS:ffff889faec00000(0000) knlGS:0000000000000000
[ 1825.352343] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1825.352417] CR2: 000056070a4d1158 CR3: 000000015efe0000 CR4: 0000000000350ee0
[ 1825.352508] Call Trace:
[ 1825.352544]  nf_ct_helper_ext_add+0x10/0x60 [nf_conntrack]
[ 1825.352641]  nft_ct_expect_obj_eval+0x1b8/0x1e0 [nft_ct]
[ 1825.352716]  nft_do_chain+0x232/0x850 [nf_tables]

Add the ct helper extension only for unconfirmed conntrack. Skip rule
evaluation if the ct helper extension does not exist. Thus, you can
only create expectations from the first packet.

It should be possible to remove this limitation by adding a new action
to attach a generic ct helper to the first packet. Then, use this ct
helper extension from follow up packets to create the ct expectation.

While at it, add a missing check to skip the template conntrack too
and remove check for IPCT_UNTRACK which is implicit to !ct.

Fixes: 857b46027d6f ("netfilter: nft_ct: add ct expectations support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_ct.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 3, 2021, 9 p.m. UTC | #1
Hello:

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

On Wed,  2 Jun 2021 14:44:29 +0200 you wrote:
> nft_ct_expect_obj_eval() calls nf_ct_ext_add() for a confirmed
> conntrack entry. However, nf_ct_ext_add() can only be called for
> !nf_ct_is_confirmed().
> 
> [ 1825.349056] WARNING: CPU: 0 PID: 1279 at net/netfilter/nf_conntrack_extend.c:48 nf_ct_xt_add+0x18e/0x1a0 [nf_conntrack]
> [ 1825.351391] RIP: 0010:nf_ct_ext_add+0x18e/0x1a0 [nf_conntrack]
> [ 1825.351493] Code: 41 5c 41 5d 41 5e 41 5f c3 41 bc 0a 00 00 00 e9 15 ff ff ff ba 09 00 00 00 31 f6 4c 89 ff e8 69 6c 3d e9 eb 96 45 31 ed eb cd <0f> 0b e9 b1 fe ff ff e8 86 79 14 e9 eb bf 0f 1f 40 00 0f 1f 44 00
> [ 1825.351721] RSP: 0018:ffffc90002e1f1e8 EFLAGS: 00010202
> [ 1825.351790] RAX: 000000000000000e RBX: ffff88814f5783c0 RCX: ffffffffc0e4f887
> [ 1825.351881] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88814f578440
> [ 1825.351971] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88814f578447
> [ 1825.352060] R10: ffffed1029eaf088 R11: 0000000000000001 R12: ffff88814f578440
> [ 1825.352150] R13: ffff8882053f3a00 R14: 0000000000000000 R15: 0000000000000a20
> [ 1825.352240] FS:  00007f992261c900(0000) GS:ffff889faec00000(0000) knlGS:0000000000000000
> [ 1825.352343] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 1825.352417] CR2: 000056070a4d1158 CR3: 000000015efe0000 CR4: 0000000000350ee0
> [ 1825.352508] Call Trace:
> [ 1825.352544]  nf_ct_helper_ext_add+0x10/0x60 [nf_conntrack]
> [ 1825.352641]  nft_ct_expect_obj_eval+0x1b8/0x1e0 [nft_ct]
> [ 1825.352716]  nft_do_chain+0x232/0x850 [nf_tables]
> 
> [...]

Here is the summary with links:
  - [net,1/2] netfilter: nft_ct: skip expectations for confirmed conntrack
    https://git.kernel.org/netdev/net/c/1710eb913bdc
  - [net,2/2] netfilter: nfnetlink_cthelper: hit EBUSY on updates if size mismatches
    https://git.kernel.org/netdev/net/c/8971ee8b0877

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 0592a9456084..337e22d8b40b 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -1217,7 +1217,7 @@  static void nft_ct_expect_obj_eval(struct nft_object *obj,
 	struct nf_conn *ct;
 
 	ct = nf_ct_get(pkt->skb, &ctinfo);
-	if (!ct || ctinfo == IP_CT_UNTRACKED) {
+	if (!ct || nf_ct_is_confirmed(ct) || nf_ct_is_template(ct)) {
 		regs->verdict.code = NFT_BREAK;
 		return;
 	}