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NVD / CVE Program· CNA Linux

CVE-2025-21858: geneve: Fix use-after-free in geneve_find_dev().

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 3ce92ca990cfac88a87c61df3cc0b5880e688ecf, 5a0538ac6826807d6919f6aecbb8996c2865af2c, 788dbca056a8783ec063da3c9d49a3a71c76c283; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1.

Low priority for now. Upgrade to Linux Linux 3ce92ca990cfac88a87c61df3cc0b5880e688ecf, 5a0538ac6826807d6919f6aecbb8996c2865af2c, 788dbca056a8783ec063da3c9d49a3a71c76c283; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: geneve: Fix use-after-free in geneve_find_dev(). syzkaller reported a use-after-free in geneve_find_dev() [0] without repro. geneve_configure() links struct geneve_dev.next to net_generic(net, geneve_net_id)->geneve_list. The net here could differ from dev_net(dev) if IFLA_NET_NS_PID, IFLA_NET_NS_FD, or IFLA_TARGET_NETNSID is set. When dev_net(dev) is dismantled, geneve_exit_batch_rtnl() finally calls unregister_netdevice_queue() for each dev in the netns, and later the dev is freed. However, its geneve_dev.next is still linked to the backend UDP socket netns. Then, use-after-free will occur when another geneve dev is created in the netns. Let's call geneve_dellink() instead in geneve_destroy_tunnels(). [0]: BUG: KASAN: slab-use-after-free in geneve_find_dev drivers/net/geneve.c:1295 [inline] BUG: KASAN: slab-use-after-free in geneve_configure+0x234/0x858 drivers/net/geneve.c:1343 Read of size 2 at addr ffff000054d6ee24 by task syz.1.4029/13441 CPU: 1 UID: 0 PID: 13441 Comm: syz.1.4029 Not tainted 6.13.0-g0ad9617c78ac #24 dc35ca22c79fb82e8e7bc5c9c9adafea898b1e3d Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x16c/0x6f0 mm/kasan/report.c:489 kasan_report+0xc0/0x120 mm/kasan/report.c:602 __asan_report_load2_noabort+0x20/0x30 mm/kasan/report_generic.c:379 geneve_find_dev drivers/net/geneve.c:1295 [inline] geneve_configure+0x234/0x858 drivers/net/geneve.c:1343 geneve_newlink+0xb8/0x128 drivers/net/geneve.c:1634 rtnl_newlink_create+0x23c/0x868 net/core/rtnetlink.c:3795 __rtnl_newlink net/core/rtnetlink.c:3906 [inline] rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x410/0x6f8 net/socket.c:2568 ___sys_sendmsg+0x178/0x1d8 net/socket.c:2622 __sys_sendmsg net/socket.c:2654 [inline] __do_sys_sendmsg net/socket.c:2659 [inline] __se_sys_sendmsg net/socket.c:2657 [inline] __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600 Allocated by task 13247: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x68 mm/kasan/common.c:68 kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4298 [inline] __kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4304 __kvmalloc_node_noprof+0x9c/0x230 mm/util.c:645 alloc_netdev_mqs+0xb8/0x11a0 net/core/dev.c:11470 rtnl_create_link+0x2b8/0xb50 net/core/rtnetlink.c:3604 rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3780 __rtnl_newlink net/core/rtnetlink.c:3906 [inline] rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938 netlink_unicast_kernel net/netlink/af_n ---truncated---

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Mar 12, 2025
Updated
Oct 15, 2026
EPSS
0.2% · 16th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
7.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.2 and later · before 6.1.130
  • linux linux kernel6.2 and later · before 6.6.80
  • linux linux kernel6.7 and later · before 6.12.17
  • linux linux kernel6.13 and later · before 6.13.5
  • linux linux kernel6.14

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.2affected
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before d5e86e27de0936f3cb0a299ce519d993e9cf3886affected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before 5a0538ac6826807d6919f6aecbb8996c2865af2caffected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before f74f6560146714241c6e167b03165ee77a86e316affected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before 904e746b2e7fa952ab8801b303ce826a63153d78affected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before 3ce92ca990cfac88a87c61df3cc0b5880e688ecfaffected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before da9b0ae47f084014b1e4b3f31f70a0defd047ff3affected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before 788dbca056a8783ec063da3c9d49a3a71c76c283affected · git
    • 2d07dc79fe04a43d82a346ced6bbf07bdb523f1b and later · before 9593172d93b9f91c362baec4643003dc29802929affected · git
    • before 4.2not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.132.1.el8_104.18.0-553.132.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10
AlmaLinux:8kernel-rt-modulesbefore 4.18.0-553.132.1.rt7.473.el8_104.18.0-553.132.1.rt7.473.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-21846Mar 12, 2025 · acct: perform last write from workqueue
    22Monitor
  • ← EarlierCVE-2025-21853Mar 12, 2025 · bpf: avoid holding freeze_mutex during mmap operation
    22Monitor
  • Later →CVE-2025-21859Mar 12, 2025 · USB: gadget: f_midi: f_midi_complete to call queue_work
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux3ce92ca990cfac88a87c61df3cc0b5880e688ecfVendor (CNA)
Linux Linux5a0538ac6826807d6919f6aecbb8996c2865af2cVendor (CNA)
Linux Linux788dbca056a8783ec063da3c9d49a3a71c76c283Vendor (CNA)
Linux Linux904e746b2e7fa952ab8801b303ce826a63153d78Vendor (CNA)
Linux Linux9593172d93b9f91c362baec4643003dc29802929Vendor (CNA)
Linux Linuxd5e86e27de0936f3cb0a299ce519d993e9cf3886Vendor (CNA)
Linux Linuxda9b0ae47f084014b1e4b3f31f70a0defd047ff3Vendor (CNA)
Linux Linuxf74f6560146714241c6e167b03165ee77a86e316Vendor (CNA)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.179.1-1 on CBL Mariner 2.05.15.179.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL Mariner 2.0CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL-Mariner 2.05.15.179.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.132.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.132.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-core4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-core4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-devel4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-modules4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-modules-extra4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-devel4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-modules4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-modules-extra4.18.0-553.132.1.rt7.473.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.133-1 · Debian:12Package registry (OSV)
red hat:kernel-rt0:4.18.0-553.132.1.rt7.473.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-core0:4.18.0-553.132.1.rt7.473.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-debug0:4.18.0-553.132.1.rt7.473.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-debug-core0:4.18.0-553.132.1.rt7.473.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)

+10

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (11 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records