{"cve":"CVE-2023-52574","nvd":{"published":"2024-03-02T22:15:49.393","modified":"2026-08-04T10:18:32.483","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nteam: fix null-ptr-deref when team device type is changed\n\nGet a null-ptr-deref bug as follows with reproducer [1].\n\nBUG: kernel NULL pointer dereference, address: 0000000000000228\n...\nRIP: 0010:vlan_dev_hard_header+0x35/0x140 [8021q]\n...\nCall Trace:\n <TASK>\n ? __die+0x24/0x70\n ? page_fault_oops+0x82/0x150\n ? exc_page_fault+0x69/0x150\n ? asm_exc_page_fault+0x26/0x30\n ? vlan_dev_hard_header+0x35/0x140 [8021q]\n ? vlan_dev_hard_header+0x8e/0x140 [8021q]\n neigh_connected_output+0xb2/0x100\n ip6_finish_output2+0x1cb/0x520\n ? nf_hook_slow+0x43/0xc0\n ? ip6_mtu+0x46/0x80\n ip6_finish_output+0x2a/0xb0\n mld_sendpack+0x18f/0x250\n mld_ifc_work+0x39/0x160\n process_one_work+0x1e6/0x3f0\n worker_thread+0x4d/0x2f0\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe5/0x120\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x34/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1b/0x30\n\n[1]\n$ teamd -t team0 -d -c '{\"runner\": {\"name\": \"loadbalance\"}}'\n$ ip link add name t-dummy type dummy\n$ ip link add link t-dummy name t-dummy.100 type vlan id 100\n$ ip link add name t-nlmon type nlmon\n$ ip link set t-nlmon master team0\n$ ip link set t-nlmon nomaster\n$ ip link set t-dummy up\n$ ip link set team0 up\n$ ip link set t-dummy.100 down\n$ ip link set t-dummy.100 master team0\n\nWhen enslave a vlan device to team device and team device type is changed\nfrom non-ether to ether, header_ops of team device is changed to\nvlan_header_ops. That is incorrect and will trigger null-ptr-deref\nfor vlan->real_dev in vlan_dev_hard_header() because team device is not\na vlan device.\n\nCache eth_header_ops in team_setup(), then assign cached header_ops to\nheader_ops of team net device when its type is changed from non-ether\nto ether to fix the bug.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/1779eb51b9cc628cee551f252701a85a2a50a457","https://git.kernel.org/stable/c/2f0acb0736ecc3eb85dc80ad2790d634dcb10b58","https://git.kernel.org/stable/c/492032760127251e5540a5716a70996bacf2a3fd","https://git.kernel.org/stable/c/a7fb47b9711101d2405b0eb1276fb1f9b9b270c7","https://git.kernel.org/stable/c/b44dd92e2afd89eb6e9d27616858e72a67bdc1a7"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:46:54.846886191+00:00"},"epss":{"cve":"CVE-2023-52574","score":0.0024,"percentile":0.15108,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}