Answer in brief
CVE-2024-56751 records a Medium severity (CVSS 5.5) vulnerability in ipv6: release nexthop on device removal. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 <77aa9855a878fb43f547ddfbda3127a1e88ad31a || >=f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 <b2f26a27ea3f72f75d18330f76f5d1007c791848 || >=f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 <43e25adc80269f917d2a195f0d59f74cdd182955 || >=f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 <a3c3f8a4d025acc8c857246ec2b812c59102487a || >=f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 <0e4c6faaef8a24b762a24ffb767280e263ef8e10 || >=f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 <eb02688c5c45c3e7af7e71f036a7144f5639cbfe | 77aa9855a878fb43f547ddfbda3127a1e88ad31a, b2f26a27ea3f72f75d18330f76f5d1007c791848, 43e25adc80269f917d2a195f0d59f74cdd182955, a3c3f8a4d025acc8c857246ec2b812c59102487a, 0e4c6faaef8a24b762a24ffb767280e263ef8e10, eb02688c5c45c3e7af7e71f036a7144f5639cbfe |
| Linux/Linuxgeneric | 5.3 | Not reported |
Published upstream
Dec 29, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.