Bug 2467099 (CVE-2025-71291)

Summary: CVE-2025-71291 kernel: misc: bcm_vk: Fix possible null-pointer dereferences in bcm_vk_read()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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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 `bcm_vk` module. A null-pointer dereference can occur within the `bcm_vk_read()` function if a specific condition is met where a pointer `entry` is NULL and an error code `-EMSGSIZE` is returned. This vulnerability could allow a local attacker to cause system instability or a denial of service (DoS).
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Description OSIDB Bzimport 2026-05-06 13:04:12 UTC 
In the Linux kernel, the following vulnerability has been resolved:

misc: bcm_vk: Fix possible null-pointer dereferences in bcm_vk_read()

In the function bcm_vk_read(), the pointer entry is checked, indicating
that it can be NULL. If entry is NULL and rc is set to -EMSGSIZE, the
following code may cause null-pointer dereferences:

  struct vk_msg_blk tmp_msg = entry->to_h_msg[0];
  set_msg_id(&tmp_msg, entry->usr_msg_id);
  tmp_msg.size = entry->to_h_blks - 1;

To prevent these possible null-pointer dereferences, copy to_h_msg,
usr_msg_id, and to_h_blks from iter into temporary variables, and return
these temporary variables to the application instead of accessing them
through a potentially NULL entry.
Comment 1 Keith Grant 2026-05-06 16:59:26 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050632-CVE-2025-71291-0029@gregkh/T