5.5
MEDIUM
CVE-2024-56751
"Linux Kernel IPv6 Nexthop Leaks Vulnerability"
Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: release nexthop on device removal The CI is hitting some aperiodic hangup at device removal time in the pmtu.sh self-test: unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 6 ref_tracker: veth_A-R1@ffff888013df15d8 has 1/5 users at dst_init+0x84/0x4a0 dst_alloc+0x97/0x150 ip6_dst_alloc+0x23/0x90 ip6_rt_pcpu_alloc+0x1e6/0x520 ip6_pol_route+0x56f/0x840 fib6_rule_lookup+0x334/0x630 ip6_route_output_flags+0x259/0x480 ip6_dst_lookup_tail.constprop.0+0x5c2/0x940 ip6_dst_lookup_flow+0x88/0x190 udp_tunnel6_dst_lookup+0x2a7/0x4c0 vxlan_xmit_one+0xbde/0x4a50 [vxlan] vxlan_xmit+0x9ad/0xf20 [vxlan] dev_hard_start_xmit+0x10e/0x360 __dev_queue_xmit+0xf95/0x18c0 arp_solicit+0x4a2/0xe00 neigh_probe+0xaa/0xf0 While the first suspect is the dst_cache, explicitly tracking the dst owing the last device reference via probes proved such dst is held by the nexthop in the originating fib6_info. Similar to commit f5b51fe804ec ("ipv6: route: purge exception on removal"), we need to explicitly release the originating fib info when disconnecting a to-be-removed device from a live ipv6 dst: move the fib6_info cleanup into ip6_dst_ifdown(). Tested running: ./pmtu.sh cleanup_ipv6_exception in a tight loop for more than 400 iterations with no spat, running an unpatched kernel I observed a splat every ~10 iterations.

INFO

Published Date :

Dec. 29, 2024, 12:15 p.m.

Last Modified :

Jan. 6, 2025, 5 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

3.6

Exploitability Score :

1.8
Public PoC/Exploit Available at Github

CVE-2024-56751 has a 2 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2024-56751 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

None

Updated: 2 days ago
4 stars 1 fork 1 watcher
Born at : April 16, 2025, 1:43 p.m. This repo has been linked 280 different CVEs too.

None

Updated: 1 month, 1 week ago
0 stars 0 fork 0 watcher
Born at : March 12, 2025, 3:57 p.m. This repo has been linked 126 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-56751 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2024-56751 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jan. 06, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.3 up to (excluding) 6.1.120 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.64 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.11.11 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.12 up to (excluding) 6.12.2
    Changed Reference Type https://git.kernel.org/stable/c/0e4c6faaef8a24b762a24ffb767280e263ef8e10 No Types Assigned https://git.kernel.org/stable/c/0e4c6faaef8a24b762a24ffb767280e263ef8e10 Patch
    Changed Reference Type https://git.kernel.org/stable/c/43e25adc80269f917d2a195f0d59f74cdd182955 No Types Assigned https://git.kernel.org/stable/c/43e25adc80269f917d2a195f0d59f74cdd182955 Patch
    Changed Reference Type https://git.kernel.org/stable/c/a3c3f8a4d025acc8c857246ec2b812c59102487a No Types Assigned https://git.kernel.org/stable/c/a3c3f8a4d025acc8c857246ec2b812c59102487a Patch
    Changed Reference Type https://git.kernel.org/stable/c/b2f26a27ea3f72f75d18330f76f5d1007c791848 No Types Assigned https://git.kernel.org/stable/c/b2f26a27ea3f72f75d18330f76f5d1007c791848 Patch
    Changed Reference Type https://git.kernel.org/stable/c/eb02688c5c45c3e7af7e71f036a7144f5639cbfe No Types Assigned https://git.kernel.org/stable/c/eb02688c5c45c3e7af7e71f036a7144f5639cbfe Patch
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Dec. 29, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: ipv6: release nexthop on device removal The CI is hitting some aperiodic hangup at device removal time in the pmtu.sh self-test: unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 6 ref_tracker: veth_A-R1@ffff888013df15d8 has 1/5 users at dst_init+0x84/0x4a0 dst_alloc+0x97/0x150 ip6_dst_alloc+0x23/0x90 ip6_rt_pcpu_alloc+0x1e6/0x520 ip6_pol_route+0x56f/0x840 fib6_rule_lookup+0x334/0x630 ip6_route_output_flags+0x259/0x480 ip6_dst_lookup_tail.constprop.0+0x5c2/0x940 ip6_dst_lookup_flow+0x88/0x190 udp_tunnel6_dst_lookup+0x2a7/0x4c0 vxlan_xmit_one+0xbde/0x4a50 [vxlan] vxlan_xmit+0x9ad/0xf20 [vxlan] dev_hard_start_xmit+0x10e/0x360 __dev_queue_xmit+0xf95/0x18c0 arp_solicit+0x4a2/0xe00 neigh_probe+0xaa/0xf0 While the first suspect is the dst_cache, explicitly tracking the dst owing the last device reference via probes proved such dst is held by the nexthop in the originating fib6_info. Similar to commit f5b51fe804ec ("ipv6: route: purge exception on removal"), we need to explicitly release the originating fib info when disconnecting a to-be-removed device from a live ipv6 dst: move the fib6_info cleanup into ip6_dst_ifdown(). Tested running: ./pmtu.sh cleanup_ipv6_exception in a tight loop for more than 400 iterations with no spat, running an unpatched kernel I observed a splat every ~10 iterations.
    Added Reference https://git.kernel.org/stable/c/0e4c6faaef8a24b762a24ffb767280e263ef8e10
    Added Reference https://git.kernel.org/stable/c/43e25adc80269f917d2a195f0d59f74cdd182955
    Added Reference https://git.kernel.org/stable/c/a3c3f8a4d025acc8c857246ec2b812c59102487a
    Added Reference https://git.kernel.org/stable/c/b2f26a27ea3f72f75d18330f76f5d1007c791848
    Added Reference https://git.kernel.org/stable/c/eb02688c5c45c3e7af7e71f036a7144f5639cbfe
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-56751 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-56751 weaknesses.

CVSS31 - Vulnerability Scoring System
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Latest DB Update: Apr. 26, 2025 5:37