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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2025-21806 Detail

Description

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).


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
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References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://git.kernel.org/stable/c/0e2f1d93d287d544d26f8ff293ea820a8079b9f8 kernel.org Patch 
https://git.kernel.org/stable/c/1489824e5226a26841c70639ebd2d1aed390764b kernel.org Patch 
https://git.kernel.org/stable/c/33e2168788f8fb5cb8bd4f36cb1ef37d1d34dada kernel.org Patch 
https://git.kernel.org/stable/c/5860abbf15eeb61838b5e32e721ba67b0aa84450 kernel.org Patch 
https://git.kernel.org/stable/c/6ce38b5a6a49e65bad163162a54cb3f104c40b48 kernel.org Patch 
https://git.kernel.org/stable/c/c337c08819a4ec49edfdcd8fc46fbee120d8a5b2 kernel.org Patch 
https://git.kernel.org/stable/c/d0e0f9c8218826926d7692980c98236d9f21fd3c kernel.org Patch 
https://git.kernel.org/stable/c/d1f9f79fa2af8e3b45cffdeef66e05833480148a kernel.org Patch 

Weakness Enumeration

CWE-ID CWE Name Source
NVD-CWE-noinfo Insufficient Information cwe source acceptance level NIST  

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-21806
NVD Published Date:
02/27/2025
NVD Last Modified:
10/27/2025
Source:
kernel.org