On 26/03/2025 11:04, Keir Fraser wrote:
The source register is not used for SET* and reading it can result in a UBSAN out-of-bounds array access error, specifically when the MOPS exception is taken from a SET* sequence with XZR (reg 31) as the source. Architecturally this is the only case where a src/dst/size field in the ESR can be reported as 31.
Prior to 2de451a329cf662b the code in do_el0_mops() was benign as the use of pt_regs_read_reg() prevented the out-of-bounds access.
Fixes: 2de451a329cf662b ("KVM: arm64: Add handler for MOPS exceptions") Cc: Kristina Martsenko kristina.martsenko@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Mark Rutland mark.rutland@arm.com Cc: Will Deacon will@kernel.org Cc: stable@vger.kernel.org Reviewed-by: Marc Zyngier maz@kernel.org Signed-off-by: Keir Fraser keirf@google.com
FWIW,
Reviewed-by: Kristina Martšenko kristina.martsenko@arm.com
Thanks, Kristina