6.11-stable review patch. If anyone has any objections, please let me know.
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From: Ilkka Koskinen ilkka@os.amperecomputing.com
commit c6c167afa090ea0451f91814e1318755a8fb8bb9 upstream.
Fix a shift-out-of-bounds bug reported by UBSAN when running VM with MTE enabled host kernel.
UBSAN: shift-out-of-bounds in arch/arm64/kvm/sys_regs.c:1988:14 shift exponent 33 is too large for 32-bit type 'int' CPU: 26 UID: 0 PID: 7629 Comm: qemu-kvm Not tainted 6.12.0-rc2 #34 Hardware name: IEI NF5280R7/Mitchell MB, BIOS 00.00. 2024-10-12 09:28:54 10/14/2024 Call trace: dump_backtrace+0xa0/0x128 show_stack+0x20/0x38 dump_stack_lvl+0x74/0x90 dump_stack+0x18/0x28 __ubsan_handle_shift_out_of_bounds+0xf8/0x1e0 reset_clidr+0x10c/0x1c8 kvm_reset_sys_regs+0x50/0x1c8 kvm_reset_vcpu+0xec/0x2b0 __kvm_vcpu_set_target+0x84/0x158 kvm_vcpu_set_target+0x138/0x168 kvm_arch_vcpu_ioctl_vcpu_init+0x40/0x2b0 kvm_arch_vcpu_ioctl+0x28c/0x4b8 kvm_vcpu_ioctl+0x4bc/0x7a8 __arm64_sys_ioctl+0xb4/0x100 invoke_syscall+0x70/0x100 el0_svc_common.constprop.0+0x48/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x158 el0t_64_sync_handler+0x120/0x130 el0t_64_sync+0x194/0x198
Fixes: 7af0c2534f4c ("KVM: arm64: Normalize cache configuration") Cc: stable@vger.kernel.org Reviewed-by: Gavin Shan gshan@redhat.com Signed-off-by: Ilkka Koskinen ilkka@os.amperecomputing.com Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com Link: https://lore.kernel.org/r/20241017025701.67936-1-ilkka@os.amperecomputing.co... Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1977,7 +1977,7 @@ static u64 reset_clidr(struct kvm_vcpu * * one cache line. */ if (kvm_has_mte(vcpu->kvm)) - clidr |= 2 << CLIDR_TTYPE_SHIFT(loc); + clidr |= 2ULL << CLIDR_TTYPE_SHIFT(loc);
__vcpu_sys_reg(vcpu, r->reg) = clidr;