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

CVE-2024-46857

Disclosure Date: September 27, 2024 •
CVE-2024-46857 CVSS v3 Base Score: 5.5
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

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

net/mlx5: Fix bridge mode operations when there are no VFs

Currently, trying to set the bridge mode attribute when numvfs=0 leads to a
crash:

bridge link set dev eth2 hwmode vepa

[ 168.967392] BUG: kernel NULL pointer dereference, address: 0000000000000030
[…]
[ 168.969989] RIP: 0010:mlx5_add_flow_rules+0x1f/0x300 [mlx5_core]
[…]
[ 168.976037] Call Trace:
[ 168.976188] <TASK>
[ 168.978620] _mlx5_eswitch_set_vepa_locked+0x113/0x230 [mlx5_core]
[ 168.979074] mlx5_eswitch_set_vepa+0x7f/0xa0 [mlx5_core]
[ 168.979471] rtnl_bridge_setlink+0xe9/0x1f0
[ 168.979714] rtnetlink_rcv_msg+0x159/0x400
[ 168.980451] netlink_rcv_skb+0x54/0x100
[ 168.980675] netlink_unicast+0x241/0x360
[ 168.980918] netlink_sendmsg+0x1f6/0x430
[ 168.981162] ____sys_sendmsg+0x3bb/0x3f0
[ 168.982155] ___sys_sendmsg+0x88/0xd0
[ 168.985036] __sys_sendmsg+0x59/0xa0
[ 168.985477] do_syscall_64+0x79/0x150
[ 168.987273] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 168.987773] RIP: 0033:0x7f8f7950f917

(esw->fdb_table.legacy.vepa_fdb is null)

The bridge mode is only relevant when there are multiple functions per
port. Therefore, prevent setting and getting this setting when there are no
VFs.

Note that after this change, there are no settings to change on the PF
interface using bridge link when there are no VFs, so the interface no
longer appears in the bridge link output.

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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

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux 52c4beb79e09
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • linux

Products

  • linux kernel,
  • linux kernel 6.11
Technical Analysis