CVE-2026-97906

In the Linux kernel, the following vulnerability has been resolved:

bootconfig: Fix integer overflow in initrd size check

Sashiko reported that in get boot config from initrd(), a crafted initrd with a huge bootconfig size (such as 0xFFFFFFFF) can cause the pointer arithmetic:

data = ((void *)hdr) - size;

to wrap around on 32-bit systems (or when pointer subtraction overflows). Because data wraps around, the subsequent bounds check:

if ((unsigned long)data < initrd start)

evaluates to false, bypassing the check. The kernel then calls xbc calc checksum(data, size), which attempts to read 4GB of memory, hitting unmapped pages and triggering a fatal kernel page fault during early boot. Furthermore, on 64-bit systems with an initrd > 4.29 GB, an unbounded 32-bit size can similarly bypass the initrd start check.

Fix this by: