ghsa-mq5p-7q76-276p
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: let net.core.dev_weight always be non-zero
The following problem was encountered during stability test:
(NULL net_device): NAPI poll function process_backlog+0x0/0x530 \ returned 1, exceeding its budget of 0. ------------[ cut here ]------------ list_add double add: new=ffff88905f746f48, prev=ffff88905f746f48, \ next=ffff88905f746e40. WARNING: CPU: 18 PID: 5462 at lib/list_debug.c:35 \ __list_add_valid_or_report+0xf3/0x130 CPU: 18 UID: 0 PID: 5462 Comm: ping Kdump: loaded Not tainted 6.13.0-rc7+ RIP: 0010:__list_add_valid_or_report+0xf3/0x130 Call Trace: ? __warn+0xcd/0x250 ? __list_add_valid_or_report+0xf3/0x130 enqueue_to_backlog+0x923/0x1070 netif_rx_internal+0x92/0x2b0 __netif_rx+0x15/0x170 loopback_xmit+0x2ef/0x450 dev_hard_start_xmit+0x103/0x490 __dev_queue_xmit+0xeac/0x1950 ip_finish_output2+0x6cc/0x1620 ip_output+0x161/0x270 ip_push_pending_frames+0x155/0x1a0 raw_sendmsg+0xe13/0x1550 __sys_sendto+0x3bf/0x4e0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e
The reproduction command is as follows: sysctl -w net.core.dev_weight=0 ping 127.0.0.1
This is because when the napi's weight is set to 0, process_backlog() may return 0 and clear the NAPI_STATE_SCHED bit of napi->state, causing this napi to be re-polled in net_rx_action() until __do_softirq() times out. Since the NAPI_STATE_SCHED bit has been cleared, napi_schedule_rps() can be retriggered in enqueue_to_backlog(), causing this issue.
Making the napi's weight always non-zero solves this problem.
Triggering this issue requires system-wide admin (setting is not namespaced).
{
"affected": [],
"aliases": [
"CVE-2025-21806"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-27T20:16:03Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: let net.core.dev_weight always be non-zero\n\nThe following problem was encountered during stability test:\n\n(NULL net_device): NAPI poll function process_backlog+0x0/0x530 \\\n\treturned 1, exceeding its budget of 0.\n------------[ cut here ]------------\nlist_add double add: new=ffff88905f746f48, prev=ffff88905f746f48, \\\n\tnext=ffff88905f746e40.\nWARNING: CPU: 18 PID: 5462 at lib/list_debug.c:35 \\\n\t__list_add_valid_or_report+0xf3/0x130\nCPU: 18 UID: 0 PID: 5462 Comm: ping Kdump: loaded Not tainted 6.13.0-rc7+\nRIP: 0010:__list_add_valid_or_report+0xf3/0x130\nCall Trace:\n? __warn+0xcd/0x250\n? __list_add_valid_or_report+0xf3/0x130\nenqueue_to_backlog+0x923/0x1070\nnetif_rx_internal+0x92/0x2b0\n__netif_rx+0x15/0x170\nloopback_xmit+0x2ef/0x450\ndev_hard_start_xmit+0x103/0x490\n__dev_queue_xmit+0xeac/0x1950\nip_finish_output2+0x6cc/0x1620\nip_output+0x161/0x270\nip_push_pending_frames+0x155/0x1a0\nraw_sendmsg+0xe13/0x1550\n__sys_sendto+0x3bf/0x4e0\n__x64_sys_sendto+0xdc/0x1b0\ndo_syscall_64+0x5b/0x170\nentry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThe reproduction command is as follows:\n sysctl -w net.core.dev_weight=0\n ping 127.0.0.1\n\nThis is because when the napi\u0027s weight is set to 0, process_backlog() may\nreturn 0 and clear the NAPI_STATE_SCHED bit of napi-\u003estate, causing this\nnapi to be re-polled in net_rx_action() until __do_softirq() times out.\nSince the NAPI_STATE_SCHED bit has been cleared, napi_schedule_rps() can\nbe retriggered in enqueue_to_backlog(), causing this issue.\n\nMaking the napi\u0027s weight always non-zero solves this problem.\n\nTriggering this issue requires system-wide admin (setting is\nnot namespaced).",
"id": "GHSA-mq5p-7q76-276p",
"modified": "2025-03-13T15:32:53Z",
"published": "2025-02-27T21:32:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21806"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0e2f1d93d287d544d26f8ff293ea820a8079b9f8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1489824e5226a26841c70639ebd2d1aed390764b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/33e2168788f8fb5cb8bd4f36cb1ef37d1d34dada"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5860abbf15eeb61838b5e32e721ba67b0aa84450"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6ce38b5a6a49e65bad163162a54cb3f104c40b48"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c337c08819a4ec49edfdcd8fc46fbee120d8a5b2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d0e0f9c8218826926d7692980c98236d9f21fd3c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d1f9f79fa2af8e3b45cffdeef66e05833480148a"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
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