Security Vulnerability Report
中文
CVE-2026-31502 CVSS 7.8 HIGH

CVE-2026-31502

Published: 2026-04-22 14:16:49
Last Modified: 2026-04-28 14:47:01
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Description

In the Linux kernel, the following vulnerability has been resolved: team: fix header_ops type confusion with non-Ethernet ports Similar to commit 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()") team has the same class of header_ops type confusion. For non-Ethernet ports, team_setup_by_port() copies port_dev->header_ops directly. When the team device later calls dev_hard_header() or dev_parse_header(), these callbacks can run with the team net_device instead of the real lower device, so netdev_priv(dev) is interpreted as the wrong private type and can crash. The syzbot report shows a crash in bond_header_create(), but the root cause is in team: the topology is gre -> bond -> team, and team calls the inherited header_ops with its own net_device instead of the lower device, so bond_header_create() receives a team device and interprets netdev_priv() as bonding private data, causing a type confusion crash. Fix this by introducing team header_ops wrappers for create/parse, selecting a team port under RCU, and calling the lower device callbacks with port->dev, so each callback always sees the correct net_device context. Also pass the selected lower device to the lower parse callback, so recursion is bounded in stacked non-Ethernet topologies and parse callbacks always run with the correct device context.

CVSS Details

CVSS Score
7.8
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:3.7:-:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* - VULNERABLE
Linux Kernel < 6.1.83
Linux Kernel < 6.6.23
Linux Kernel < 6.7.11
Linux Kernel < 6.8.2

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/if.h> #include <linux/netlink.h> #include <linux/rtnetlink.h> // Simplified PoC concept to reproduce the topology: gre -> bond -> team // This requires root privileges to manipulate network interfaces. void send_netlink_msg(int sock, struct nlmsghdr *nlh) { send(sock, nlh, nlh->nlmsg_len, 0); } int main() { int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock < 0) { perror("socket"); return 1; } struct sockaddr_nl src_addr; memset(&src_addr, 0, sizeof(src_addr)); src_addr.nl_family = AF_NETLINK; bind(sock, (struct sockaddr *)&src_addr, sizeof(src_addr)); // 1. Create a GRE interface (Non-Ethernet) printf("[*] Creating GRE interface...\n"); // Code to create 'gre0' would go here using RTM_NEWLINK // 2. Create a Bonding interface printf("[*] Creating Bonding interface...\n"); // Code to create 'bond0' and enslave gre0 would go here // 3. Create a Team interface printf("[*] Creating Team interface...\n"); // Code to create 'team0' and enslave bond0 would go here // This triggers the vulnerable path in team_setup_by_port // 4. Trigger the vulnerability // Sending traffic that invokes dev_hard_header() on the team device // causes the crash because bond_header_create runs with team's net_device. printf("[*] Triggering header_ops confusion...\n"); close(sock); return 0; }

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-31502", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-22T14:16:48.713", "lastModified": "2026-04-28T14:47:01.397", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nteam: fix header_ops type confusion with non-Ethernet ports\n\nSimilar to commit 950803f72547 (\"bonding: fix type confusion in\nbond_setup_by_slave()\") team has the same class of header_ops type\nconfusion.\n\nFor non-Ethernet ports, team_setup_by_port() copies port_dev->header_ops\ndirectly. When the team device later calls dev_hard_header() or\ndev_parse_header(), these callbacks can run with the team net_device\ninstead of the real lower device, so netdev_priv(dev) is interpreted as\nthe wrong private type and can crash.\n\nThe syzbot report shows a crash in bond_header_create(), but the root\ncause is in team: the topology is gre -> bond -> team, and team calls\nthe inherited header_ops with its own net_device instead of the lower\ndevice, so bond_header_create() receives a team device and interprets\nnetdev_priv() as bonding private data, causing a type confusion crash.\n\nFix this by introducing team header_ops wrappers for create/parse,\nselecting a team port under RCU, and calling the lower device callbacks\nwith port->dev, so each callback always sees the correct net_device\ncontext.\n\nAlso pass the selected lower device to the lower parse callback, so\nrecursion is bounded in stacked non-Ethernet topologies and parse\ncallbacks always run with the correct device context."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-843"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7.1", "versionEndExcluding": "6.12.80", "matchCriteriaId": "D205AD2D-8373-44D8-BB6D-74C87BD8E73A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.21", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.11", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:3.7:-:*:*:*:*:*:*", "matchCriteriaId": "F482CC77-4452-423A-8A57-523E1AEA1087"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0a7468ed49a6b65d34abcc6eb60e15f7f6d34da0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/20491d384d973a63fbdaf7a71e38d69b0659ea55", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/425000dbf17373a4ab8be9428f5dc055ef870a56", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/6d3161fa3eee64d46b766fb0db33ec7f300ef52d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}