CVE-2024-36883: net: fix out-of-bounds access in ops_init

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-30 · updated 2026-08-04
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: net: fix out-of-bounds access in ops_init net_alloc_generic is called by net_alloc, which is called without any locking. It reads max_gen_ptrs, which is changed under pernet_ops_rwsem. It is read twice, first to allocate an array, then to set s.len, which is later used to limit the bounds of the array access. It is possible that the array is allocated and another thread is registering a new pernet ops, increments max_gen_ptrs, which is then used to set s.len with a larger than allocated length for the variable array. Fix it by reading max_gen_ptrs only once in net_alloc_generic. If max_gen_ptrs is later incremented, it will be caught in net_assign_generic.

Affected products

Debian Linux: 10.0
Linux kernel: from 3.0.19 before 3.1; from 3.2.3 before 3.3; from 3.3.1 before 4.19.314; from 4.20 before 5.4.276; from 5.5 before 5.10.217; from 5.11 before 5.15.159 — fixed in 3.1, 3.3, 4.19.314, 5.10.217, 5.15.159, 5.4.276

How to fix

Upgrade to a fixed version: Linux kernel 3.1, 3.3, 4.19.314, 5.10.217. Check the vendor advisory for mitigations.

References

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