CVE-2026-64244

Description

In the Linux kernel, the following vulnerability has been resolved: drivers/base/memory: set mem->altmap after successful device registration If __add_memory_block() fails at xa_store() (under memory pressure for example), device_unregister() is called, which eventually triggers memory_block_release() with mem->altmap still set, causing a WARN_ON(mem->altmap). This was triggered by modifying virtio-mem driver. Fix this by delaying the assignment of mem->altmap until after __add_memory_block() has succeeded.

References

• https://git.kernel.org/stable/c/059ac6252a63edf1cea79bf30bd860a8c264b62c
• https://git.kernel.org/stable/c/22dc0d042f02ce82aa61422ea5f232628bfd9e9c
• https://git.kernel.org/stable/c/6c25bf4e44a2b6a14332f952bba0974521f5b72d
• https://git.kernel.org/stable/c/802e113cf120df7208e4c7e604950a85e87120a8
• https://git.kernel.org/stable/c/a2b8d7827f48ee54a686cb80e4a1d0ff954ec42a