Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-72444— flow_dissector: check device type before reading ETH_ADDRS

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel 4.2版本存在安全漏洞，该漏洞源于net/core/flow_dissector.c中的__skb_flow_dissect函数在请求FLOW_DISSECTOR_KEY_ETH_ADDRS时未检查设备类型和mac_header有效性，无条件读取eth_hdr(skb)的12字节数据，导致在TUN设备L3模式下读取未初始化内存，可能造成信息泄露或过滤器匹配异常。

CVSS 7.8 · High EPSS 0.18% · P7

Affected Version Matrix 14

VendorProduct Version RangeStatus
Linux Linux 67a900cc0436d74e7ff89042371760def087680d< 0fe6455b8e1a22414f39c07bc90a1df12b52ec74 affected
67a900cc0436d74e7ff89042371760def087680d< 9a65860959db594dfc1820c7fdc09285fb7556bf affected
67a900cc0436d74e7ff89042371760def087680d< 594c90b197141944f25991b8314de5c26ee27a7e affected
67a900cc0436d74e7ff89042371760def087680d< c6d3bcb0f934d4297ac5fa1c8656ae40694fb601 affected
67a900cc0436d74e7ff89042371760def087680d< 825de39f0c35a112148799b3cbe45af3766c018a affected
67a900cc0436d74e7ff89042371760def087680d< bf6e8af2c8be77489bedeae9f8a9654cb710e500 affected
4.2 affected
< 4.2 unaffected
… +6 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-72444

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
flow_dissector: check device type before reading ETH_ADDRS
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: flow_dissector: check device type before reading ETH_ADDRS __skb_flow_dissect() unconditionally reads 12 bytes from eth_hdr(skb) when FLOW_DISSECTOR_KEY_ETH_ADDRS is requested. This assumes the skb has a valid Ethernet header at mac_header, which is not always the case. The problem can be triggered by: 1. Creating a TUN device in L3 mode (IFF_TUN, hard_header_len=0) 2. Attaching a multiq qdisc with a flower filter matching on eth_src 3. Sending a packet through AF_PACKET Since TUN in L3 mode has no link-layer header, mac_header points to the L3 data area. The flow dissector reads 12 bytes of uninitialized skb memory, which then propagates through fl_set_masked_key() and is used as a rhashtable lookup key in __fl_lookup(), as reported by KMSAN. Rejecting the filter in the control path (at tc filter add time) is not feasible because TC filter blocks can be shared between arbitrary devices -- a filter installed on an Ethernet device may later classify packets on a headerless device through a shared block. The device association is not fixed at filter creation time. Fix this by gating the memcpy on dev->type == ARPHRD_ETHER, which ensures only true Ethernet-framed packets have their addresses read. This is more precise than the previous hard_header_len >= 12 check, which would incorrectly pass for non-Ethernet link types like IPoIB (ARPHRD_INFINIBAND, hard_header_len=24) and FDDI (hard_header_len=21) whose L2 headers are not in Ethernet format. Additionally check skb_mac_header_was_set() to guard against the pathological case where mac_header is the unset sentinel (~0U), which would cause eth_hdr() to return a wild pointer. For the act_mirred redirect case (Ethernet packet redirected to a non-Ethernet device sharing a TC block), zeroing the key is the correct behavior: the packet is now being classified on the target device, where Ethernet address matching is not semantically meaningful. Note: on non-Ethernet devices, the zeroed key will match a filter configured with all-zero MAC addresses. This is an improvement over the previous behavior where uninitialized memory could randomly match any filter.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel 4.2版本存在安全漏洞，该漏洞源于net/core/flow_dissector.c中的__skb_flow_dissect函数在请求FLOW_DISSECTOR_KEY_ETH_ADDRS时未检查设备类型和mac_header有效性，无条件读取eth_hdr(skb)的12字节数据，导致在TUN设备L3模式下读取未初始化内存，可能造成信息泄露或过滤器匹配异常。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 67a900cc0436d74e7ff89042371760def087680d ~ 0fe6455b8e1a22414f39c07bc90a1df12b52ec74 -
Linux Linux 4.2 -

II. Public POCs for CVE-2026-72444

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-72444

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-72444 (6)

Same Patch Batch · Linux · 2026-08-15 · 844 CVEs total

CVE-2026-74280 10.0 CRITICAL crypto: marvell/octeontx - fix DMA cleanup using wrong loop index
CVE-2026-74279 10.0 CRITICAL crypto: cavium/cpt - fix DMA cleanup using wrong loop index
CVE-2026-74475 10.0 CRITICAL vxlan: use neigh_ha_snapshot() in route_shortcircuit()
CVE-2026-72421 10.0 CRITICAL ipv4: fib: Don't ignore error route in local/main tables.
CVE-2026-74309 10.0 CRITICAL vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler
CVE-2026-72407 10.0 CRITICAL geneve: validate inner network offset in geneve_gro_complete()
CVE-2026-72408 10.0 CRITICAL geneve: gate GRO hint in geneve_gro_complete() on gs->gro_hint
CVE-2026-72493 9.9 CRITICAL net: serialize netif_running() check in enqueue_to_backlog()
CVE-2026-72319 9.8 CRITICAL ipvs: ensure inner headers in ICMP errors are in headroom
CVE-2026-72220 9.8 CRITICAL sunrpc: harden rq_procinfo lifecycle to prevent double-free
CVE-2026-72217 9.8 CRITICAL SUNRPC: Bound-check xdr_buf_to_bvec() stores before writing
CVE-2026-74384 9.8 CRITICAL nvme-multipath: fix flex array size in struct nvme_ns_head
CVE-2026-72299 9.8 CRITICAL tipc: restrict socket queue dumps in enqueue tracepoints
CVE-2026-72210 9.8 CRITICAL ntfs: fix off-by-one in mapping pairs decoding bounds checks
CVE-2026-72211 9.8 CRITICAL ntfs: grow index root value before reparent header update
CVE-2026-72317 9.8 CRITICAL SUNRPC: pin upper rpc_clnt across the TLS connect_worker
CVE-2026-72209 9.8 CRITICAL ntfs: validate attribute values on lookup
CVE-2026-74268 9.8 CRITICAL tcp: clear sock_ops cb flags before force-closing a child socket
CVE-2026-72207 9.8 CRITICAL ntfs: not change 0-byte $DATA attribute to non-resident
CVE-2026-74267 9.8 CRITICAL net/sched: sch_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring q

Showing top 20 of 844 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-72444

No comments yet

Leave a comment