In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_ct: skip expectations for confirmed conntrack
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.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
ubuntu | 20.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws-5.4 | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-azure | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-azure-5.4 | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-bluefield | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-gcp | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-gcp-5.4 | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-gkeop | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-hwe-5.4 | < any | UNKNOWN |
git.kernel.org/linus/1710eb913bdcda3917f44d383c32de6bdabfc836 (5.13-rc5)
git.kernel.org/stable/c/1710eb913bdcda3917f44d383c32de6bdabfc836
git.kernel.org/stable/c/2c0e6b35b88a961127066a1028bce9c727cbc3e5
git.kernel.org/stable/c/5f3429c05e4028a0e241afdad856dd15dec2ffb9
git.kernel.org/stable/c/da8d31e80ff425f5a65dab7060d5c4aba749e562
launchpad.net/bugs/cve/CVE-2021-47129
nvd.nist.gov/vuln/detail/CVE-2021-47129
security-tracker.debian.org/tracker/CVE-2021-47129
www.cve.org/CVERecord?id=CVE-2021-47129