Buffer Allocation Flaw in Linux Kernel Affecting System Integrity

CVE-2025-39836

What is CVE-2025-39836?

A vulnerability has been identified in the Linux kernel stemming from an incorrect buffer allocation method within the EFI STMM subsystem. The issue arises when the communication buffer allocated by the setup_mm_hdr() function is passed to tee_shm_register_kernel_buf(), which requires contiguous page buffers. Instead of using alloc_pages_exact(), the initial method utilized kmalloc(), leading to potential memory corruption and system instability. This flaw has been acknowledged since earlier commits and has now been corrected to enhance system stability and reliability.

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