CVE-2026-89926

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < aef540194effd768bed0bd2e6a74fe135a3d7c3aaffected
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < 71153d3262517e1c02c3a66aa5094f279b2d1454affected
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < fec89d327d9b2b669b5bbdac209386c6317c3722affected
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < b94ab9caa5d72c78226121cccff5e33f946da900affected
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < beb9c55af609c4c7308259d7191688c75a4e3d4aaffected
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < 3fe801db90bdeefb0bbdda42d832846b53f64f8aaffected
LinuxLinux27291e2165b6de70c476b7b675308113edd69a60 < 4c07680a467e2f7697245bcd11691bffb2a6f0edaffected
LinuxLinux3.16affected
LinuxLinux0 < 3.16unaffected
LinuxLinux5.15.221 <= 5.15.*unaffected
LinuxLinux6.1.188 <= 6.1.*unaffected
LinuxLinux6.6.157 <= 6.6.*unaffected
LinuxLinux6.12.110 <= 6.12.*unaffected
LinuxLinux6.18.51 <= 6.18.*unaffected
LinuxLinux7.2.5 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References