| Message ID | 20241017025701.67936-1-ilkka@os.amperecomputing.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: arm64: Fix shift-out-of-bounds bug | expand |
On 10/17/24 08:27, Ilkka Koskinen wrote: > 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> > --- > arch/arm64/kvm/sys_regs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 375052d8cd22..ff8c4e1b847e 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -1994,7 +1994,7 @@ static u64 reset_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > * 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; > clidr being u64, 2ULL is preferred over 2UL. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
On Wed, 16 Oct 2024 19:57:01 -0700, Ilkka Koskinen wrote: > 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 > > [...] Applied to fixes, thanks! [1/1] KVM: arm64: Fix shift-out-of-bounds bug commit: c6c167afa090ea0451f91814e1318755a8fb8bb9 Cheers, M.
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 375052d8cd22..ff8c4e1b847e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1994,7 +1994,7 @@ static u64 reset_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) * 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;
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> --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)