Bug 2554830 (CVE-2026-98469) - CVE-2026-98469 kernel: KVM: arm64: Fix AArch32 DBGBXVR<n> handling
Summary: CVE-2026-98469 kernel: KVM: arm64: Fix AArch32 DBGBXVR<n> handling
Keywords:
Status: NEW
Alias: CVE-2026-98469
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-18 15:21 UTC by OSIDB Bzimport
Modified: 2026-10-20 08:34 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-10-18 15:21:32 UTC
In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Fix AArch32 DBGBXVR<n> handling

The consolidation of the breakpoint and watchpoint register accessors
switched DBGBXVR<n> from trap_bvr() to trap_dbg_wb_reg(). The latter
selects backing storage with demux_wb_reg(), which only handles Op2 values
4 through 7. Since DBGBXVR<n> uses Op2 1, an AArch32 guest access hits
KVM_BUG_ON() and marks the VM dead.

DBGBXVR<n> aliases DBGBVR<n>_EL1[63:32], and its AA32(HI) descriptor
already selects the upper half. Map Op2 1 to dbg_bvr[] alongside Op2 4,
restoring the pre-regression behavior.


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