Bug 2516513 (CVE-2026-72013)

Summary: CVE-2026-72013 kernel: riscv: Prevent NULL pointer dereference in machine_kexec_prepare()
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
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. Specifically, within the riscv architecture's `machine_kexec_prepare()` function, a NULL pointer dereference can occur. This vulnerability arises when a NULL buffer is copied without proper validation during the kexec preparation process. An attacker could potentially exploit this to cause a system crash, leading to a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-15 06:16:26 UTC
In the Linux kernel, the following vulnerability has been resolved:

riscv: Prevent NULL pointer dereference in machine_kexec_prepare()

A NULL pointer dereference issue is noticed in riscv's
machine_kexec_prepare(), where image->segment[i].buf might be NULL and
copied unchecked.

The NULL buf comes from ima_add_kexec_buffer(), where kbuf is added by
kexec_add_buffer(), but kbuf.buffer is NULL, then it is copied without
a check in machine_kexec_prepare():

  kexec_file_load
    -> kimage_file_alloc_init()
       -> kimage_file_prepare_segments()
          -> ima_add_kexec_buffer()
             -> kexec_add_buffer()
    -> machine_kexec_prepare()
       -> memcpy()

Address this by adding a check before the data copy attempt.