CVE-2026-89926

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix length check __import_wp_info() struct kvm_hw_breakpoint::len is a __u64 that is fully controlled by user space. This is then assigned to wp_info->len, which is an int. The bounds check is done on the truncated value while the allocation uses the untruncated one: wp_info->len = bp_data->len; [...] if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE) return -EINVAL; wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL_ACCOUNT); Use the validated value for the allocation as intended. Without this fix userspace can trigger >4GB allocations which will fail and result in a WARN due to MAX_PAGE_ORDER.

References

• https://git.kernel.org/stable/c/3fe801db90bdeefb0bbdda42d832846b53f64f8a
• https://git.kernel.org/stable/c/4c07680a467e2f7697245bcd11691bffb2a6f0ed
• https://git.kernel.org/stable/c/71153d3262517e1c02c3a66aa5094f279b2d1454
• https://git.kernel.org/stable/c/aef540194effd768bed0bd2e6a74fe135a3d7c3a
• https://git.kernel.org/stable/c/b94ab9caa5d72c78226121cccff5e33f946da900