CVE-2026-43238

MEDIUM

net/sched: act_skbedit: fix divide-by-zero in tcf_skbedit_hash()

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_skbedit: fix divide-by-zero in tcf_skbedit_hash() Commit 38a6f0865796 ("net: sched: support hash selecting tx queue") added SKBEDIT_F_TXQ_SKBHASH support. The inclusive range size is computed as: mapping_mod = queue_mapping_max - queue_mapping + 1; The range size can be 65536 when the requested range covers all possible u16 queue IDs (e.g. queue_mapping=0 and queue_mapping_max=U16_MAX). That value cannot be represented in a u16 and previously wrapped to 0, so tcf_skbedit_hash() could trigger a divide-by-zero: queue_mapping += skb_get_hash(skb) % params->mapping_mod; Compute mapping_mod in a wider type and reject ranges larger than U16_MAX to prevent params->mapping_mod from becoming 0 and avoid the crash.

Scores

CVSS v3 5.5
EPSS 0.0001
EPSS Percentile 2.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-369
Status published
Products (15)
Linux/Linux < 5.19
Linux/Linux 38a6f0865796e26fc38fff4858f681d9ae76fa0f - 015cebdfcb97b5347fb7f598ea712a281cb35840
Linux/Linux 38a6f0865796e26fc38fff4858f681d9ae76fa0f - 3c2b95b26860bd6f8e2310d31ea1200d3f8f173e
Linux/Linux 38a6f0865796e26fc38fff4858f681d9ae76fa0f - 4ece5eb4836f8ff03b9004dc2430a7169f282851
Linux/Linux 38a6f0865796e26fc38fff4858f681d9ae76fa0f - 59809fda4da7730cfe84a948033f47eb45db073d
Linux/Linux 38a6f0865796e26fc38fff4858f681d9ae76fa0f - 9c735a7d98c982a786b0db71eb6566ee00aaa04f
Linux/Linux 38a6f0865796e26fc38fff4858f681d9ae76fa0f - be054cc66f739a9ba615dba9012a07fab8e7dd6f
Linux/Linux 5.19
Linux/Linux 6.1.165 - 6.1.*
Linux/Linux 6.12.75 - 6.12.*
... and 5 more
Published May 06, 2026
Tracked Since May 06, 2026