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NVD / CVE Program· CNA Linux

CVE-2025-21925: llc: do not use skb_get() before dev_queue_xmit()

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.23% (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 056e8a46d79e22983bae4267e0d9c52927076f46, 0f764208dc24ea043c3e20194d32aebf94f8459c, 13f3f872627f0f27c31245524fc11367756240ad.

Low priority for now. Upgrade to Linux Linux 056e8a46d79e22983bae4267e0d9c52927076f46, 0f764208dc24ea043c3e20194d32aebf94f8459c, 13f3f872627f0f27c31245524fc11367756240ad 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: llc: do not use skb_get() before dev_queue_xmit() syzbot is able to crash hosts [1], using llc and devices not supporting IFF_TX_SKB_SHARING. In this case, e1000 driver calls eth_skb_pad(), while the skb is shared. Simply replace skb_get() by skb_clone() in net/llc/llc_s_ac.c Note that e1000 driver might have an issue with pktgen, because it does not clear IFF_TX_SKB_SHARING, this is an orthogonal change. We need to audit other skb_get() uses in net/llc. [1] kernel BUG at net/core/skbuff.c:2178 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 UID: 0 PID: 16371 Comm: syz.2.2764 Not tainted 6.14.0-rc4-syzkaller-00052-gac9c34d1e45a #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:pskb_expand_head+0x6ce/0x1240 net/core/skbuff.c:2178 Call Trace: <TASK> __skb_pad+0x18a/0x610 net/core/skbuff.c:2466 __skb_put_padto include/linux/skbuff.h:3843 [inline] skb_put_padto include/linux/skbuff.h:3862 [inline] eth_skb_pad include/linux/etherdevice.h:656 [inline] e1000_xmit_frame+0x2d99/0x5800 drivers/net/ethernet/intel/e1000/e1000_main.c:3128 __netdev_start_xmit include/linux/netdevice.h:5151 [inline] netdev_start_xmit include/linux/netdevice.h:5160 [inline] xmit_one net/core/dev.c:3806 [inline] dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3822 sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343 __dev_xmit_skb net/core/dev.c:4045 [inline] __dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4621 dev_queue_xmit include/linux/netdevice.h:3313 [inline] llc_sap_action_send_test_c+0x268/0x320 net/llc/llc_s_ac.c:144 llc_exec_sap_trans_actions net/llc/llc_sap.c:153 [inline] llc_sap_next_state net/llc/llc_sap.c:182 [inline] llc_sap_state_process+0x239/0x510 net/llc/llc_sap.c:209 llc_ui_sendmsg+0xd0d/0x14e0 net/llc/af_llc.c:993 sock_sendmsg_nosec net/socket.c:718 [inline]

Published
Apr 1, 2025
Updated
Nov 10, 2026
EPSS
0.2% · 14th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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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

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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before cd1c44327bbbd50fc24f2b38892f5f328b784d0faffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 13f3f872627f0f27c31245524fc11367756240adaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 9b6f083db141ece0024be01526aa05aa978811cbaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 17f86e25431ebc15aa9245ff156414fdad47822daffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 416e8b4c20c6398044e93008deefd563289f477daffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0f764208dc24ea043c3e20194d32aebf94f8459caffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 056e8a46d79e22983bae4267e0d9c52927076f46affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 64e6a754d33d31aa844b3ee66fb93ac84ca1565eaffected · git
    • before 2.6.12not affected · semver
Affected versions · NVD (9)

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

  • linux linux kernel2.6.13 and later · before 5.4.291
  • linux linux kernel5.5 and later · before 5.10.235
  • linux linux kernel5.11 and later · before 5.15.179
  • linux linux kernel5.16 and later · before 6.1.131
  • linux linux kernel6.2 and later · before 6.6.83
  • linux linux kernel6.7 and later · before 6.12.19
  • linux linux kernel6.13 and later · before 6.13.7
  • linux linux kernel2.6.12
  • linux linux kernel6.14

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.133-16.1.133-1
Debian:13linuxbefore 6.12.19-16.12.19-1

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-2025-21921Apr 1, 2025 · net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device
    22Monitor
  • ← EarlierCVE-2025-21924Apr 1, 2025 · net: hns3: make sure ptp clock is unregister and freed if hclge_ptp_get_cycle returns an error
    22Monitor
  • Later →CVE-2025-21926Apr 1, 2025 · net: gso: fix ownership in __udp_gso_segment
    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 Linux056e8a46d79e22983bae4267e0d9c52927076f46Vendor (CNA)
Linux Linux0f764208dc24ea043c3e20194d32aebf94f8459cVendor (CNA)
Linux Linux13f3f872627f0f27c31245524fc11367756240adVendor (CNA)
Linux Linux17f86e25431ebc15aa9245ff156414fdad47822dVendor (CNA)
Linux Linux416e8b4c20c6398044e93008deefd563289f477dVendor (CNA)
Linux Linux64e6a754d33d31aa844b3ee66fb93ac84ca1565eVendor (CNA)
Linux Linux9b6f083db141ece0024be01526aa05aa978811cbVendor (CNA)
Linux Linuxcd1c44327bbbd50fc24f2b38892f5f328b784d0fVendor (CNA)
debian:linux6.1.133-1 · Debian:12Package registry (OSV)

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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

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.

References

Show all references (11 more)

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

All records