Kernel Memory Management Flaw in Linux Affects Rockchip Devices

CVE-2026-98884

What is CVE-2026-98884?

A vulnerability in the Linux kernel's management of memory, specifically within the MMC (MultiMediaCard) core, can result in memory access errors when host drivers incorrectly set the max_segs field. This field, intended as an unsigned short, can be improperly set to an excessively large value that gets truncated to zero. The issue arises in the mmc_alloc_sg() function when this zero value leads to a request for zero size allocation, which, under the SLUB memory allocator, resolves to a special pointer (ZERO_SIZE_PTR). This causes subsequent access attempts by sg_init_table() to lead to undesirable behavior and kernel crashes. The fix introduces validation checks to detect zero segment lengths and safely return an error, thereby preventing possible system failures.

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