Bug 2521477 (CVE-2026-74720)

Summary: CVE-2026-74720 kernel: bpf: Preserve pointer state for commuted arithmetic
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) component. When a scalar value is added to a pointer during certain arithmetic operations, the system fails to fully preserve the pointer's state. This inconsistency in how the pointer's origin and properties are tracked can lead to memory corruption or information disclosure. An attacker could potentially leverage this to impact system stability or gain unauthorized access to sensitive data.
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Description OSIDB Bzimport 2026-08-22 15:47:29 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: Preserve pointer state for commuted arithmetic

When scalar += pointer is handled in adjust_ptr_min_max_vals(), the
destination register inherits the pointer state from the source pointer.
Copying only selected fields is fragile because pointer provenance is
tracked by several bpf_reg_state fields.

Use the caller's temporary offset register to preserve the scalar operand
while replacing the destination with the full pointer state. This preserves
the frame number for PTR_TO_STACK registers and keeps parent identity
fields consistent.
Comment 1 Keith Grant 2026-08-24 18:09:17 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082239-CVE-2026-74720-a11f@gregkh/T