Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2022-48974

Disclosure Date: October 21, 2024
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: conntrack: fix using __this_cpu_add in preemptible

Currently in nf_conntrack_hash_check_insert(), when it fails in
nf_ct_ext_valid_pre/post(), NF_CT_STAT_INC() will be called in the
preemptible context, a call trace can be triggered:

BUG: using __this_cpu_add() in preemptible [00000000] code: conntrack/1636
caller is nf_conntrack_hash_check_insert+0x45/0x430 [nf_conntrack]
Call Trace:

<TASK>
dump_stack_lvl+0x33/0x46
check_preemption_disabled+0xc3/0xf0
nf_conntrack_hash_check_insert+0x45/0x430 [nf_conntrack]
ctnetlink_create_conntrack+0x3cd/0x4e0 [nf_conntrack_netlink]
ctnetlink_new_conntrack+0x1c0/0x450 [nf_conntrack_netlink]
nfnetlink_rcv_msg+0x277/0x2f0 [nfnetlink]
netlink_rcv_skb+0x50/0x100
nfnetlink_rcv+0x65/0x144 [nfnetlink]
netlink_unicast+0x1ae/0x290
netlink_sendmsg+0x257/0x4f0
sock_sendmsg+0x5f/0x70

This patch is to fix it by changing to use NF_CT_STAT_INC_ATOMIC() for
nf_ct_ext_valid_pre/post() check in nf_conntrack_hash_check_insert(),
as well as nf_ct_ext_valid_post() in __nf_conntrack_confirm().

Note that nf_ct_ext_valid_pre() check in __nf_conntrack_confirm() is
safe to use NF_CT_STAT_INC(), as it’s under local_bh_disable().

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CVSS V3 Severity and Metrics
Base Score:
5.5 Medium
Impact Score:
3.6
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Vendors

  • linux

Products

  • linux kernel,
  • linux kernel 6.1

Additional Info

Technical Analysis