CVE-2026-43333
Kernel NULL Dereference in Linux Kernel BPF Subsystem
Publication date: 2026-05-08
Last updated on: 2026-05-08
Assigner: kernel.org
Description
Description
CVSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's handling of BPF (Berkeley Packet Filter) pointers. Specifically, the function check_mem_access() incorrectly matches PTR_TO_BUF pointers by stripping the PTR_MAYBE_NULL attribute, which allows direct dereferencing without checking if the pointer is null.
In map iterator callbacks, the context keys and values are pointers that can be null (PTR_TO_BUF combined with PTR_MAYBE_NULL). When stop callbacks occur, these pointers can be null, leading to a kernel NULL pointer dereference.
The fix involved adding a guard (type_may_be_null()) to properly handle nullable pointers in the PTR_TO_BUF branch, preventing unsafe dereferencing.
How can this vulnerability impact me? :
This vulnerability can cause a kernel NULL pointer dereference, which typically leads to a kernel crash or system instability.
Such crashes can result in denial of service (DoS) conditions, potentially disrupting normal system operations and availability.