CVE-2026-43238

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

MEDIUM
5.5
CVSS Score
Published: May 6, 2026 at 11:28 AM UTC
Updated: June 17, 2026 at 10:49 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.19 ≤ v < 6.1.1655.19 ≤ v < 6.12.755.19 ≤ v < 6.18.165.19 ≤ v < 6.19.65.19 ≤ v < 6.6.1285.19 ≤ v < 7.06.13 ≤ v < 6.18.166.19 ≤ v < 6.19.66.2 ≤ v < 6.6.1286.7 ≤ v < 6.12.7538a6f0865796e26fc38fff4858f681d9ae76fa0f5.19
Vendor states this is fixed in 015cebdfcb97b5347fb7f598ea712a281cb35840 (fixed)
Vendor states this is fixed in 3c2b95b26860bd6f8e2310d31ea1200d3f8f173e (fixed)
Vendor states this is fixed in 4ece5eb4836f8ff03b9004dc2430a7169f282851 (fixed)
Vendor states this is fixed in 59809fda4da7730cfe84a948033f47eb45db073d (fixed)
Vendor states this is fixed in 9c735a7d98c982a786b0db71eb6566ee00aaa04f (fixed)
Vendor states this is fixed in be054cc66f739a9ba615dba9012a07fab8e7dd6f (fixed)
Vendor states this is fixed in 5.19 (unaffected)
Vendor states this is fixed in 6.1.165 (unaffected)
Vendor states this is fixed in 6.12.75 (unaffected)
Vendor states this is fixed in 6.18.16 (unaffected)
Vendor states this is fixed in 6.19.6 (unaffected)
Vendor states this is fixed in 6.6.128 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-369

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