CVE-2025-71291 misc: bcm_vk: Fix possible null-pointer dereferences in bcm_vk_read()
A null-pointer dereference in the Linux kernel's bcm_vk driver can cause a system crash, requiring a kernel patch to prevent denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-71291?
CVE-2025-71291 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-476
Which versions are affected by CVE-2025-71291?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-71291?
Apply the vendor's patch.
Is CVE-2025-71291 being exploited?
There is no known exploitation of CVE-2025-71291 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-71291, DEBIAN-CVE-2025-71291, GHSA-85c9-wpp9-8pg8, ROOT-OS-DEBIAN-11-CVE-2025-71291, ROOT-OS-UBUNTU-2204-CVE-2025-71291, ROOT-OS-UBUNTU-2404-CVE-2025-71291 and 1 more.