Linux Kernel CVE-2026-43149

The vulnerability resides in drivers/net/wan/fsl_ucc_hdlc.c, the Freescale Universal Communication Controller (UCC) HDLC WAN driver used on QorIQ and PowerPC SoC platforms. The root cause is improper DMA resource lifecycle management: uhdlc_init() allocates a single contiguous coherent DMA buffer and assigns pointers priv->rx_buffer and priv->tx_buffer into different offsets of that allocation. The cleanup routine uhdlc_memclean() then calls dma_free_coherent() independently on each pointer, which constitutes a double-free of overlapping DMA memory - the first call frees the entire allocation, and the second call attempts to free a pointer into already-freed memory. While no CWE is formally assigned in the NVD entry, this maps closest to CWE-415 (Double Free) or CWE-762 (Mismatched Memory Management Routines) in DMA context. The CVSS vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H accurately reflects a local, low-complexity crash condition with no confidentiality or integrity impact. The 'Information Disclosure' tag appears to be a tagging artifact - the CVSS explicitly assigns C:N, and the fix description supports a pure availability impact. Affected CPE: cpe:2.3:a:linux:linux across multiple stable branches since the vulnerability was introduced at commit c19b6d246a35627c3a69b2fa6bdece212b48214b (Linux 4.8).