Re:[PATCH] KVM: SVM: fix panic on out-of-bounds guest IRQ

[wang.yi59]

Hi Paolo,

> On 3/9/22 12:30, Yi Wang wrote:
> > As guest_irq is coming from KVM_IRQFD API call, it may trigger
> > crash in svm_update_pi_irte() due to out-of-bounds:
> > 
> > crash> bt
> > PID: 22218  TASK: ffff951a6ad74980  CPU: 73  COMMAND: "vcpu8"
> >   #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397
> >   #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d
> >   #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d
> >   #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d
> >   #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9
> >   #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51
> >   #6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace
> >      [exception RIP: svm_update_pi_irte+227]
> >      RIP: ffffffffc0761b53  RSP: ffffb1ba6707fd08  RFLAGS: 00010086
> >      RAX: ffffb1ba6707fd78  RBX: ffffb1ba66d91000  RCX: 0000000000000001
> >      RDX: 00003c803f63f1c0  RSI: 000000000000019a  RDI: ffffb1ba66db2ab8
> >      RBP: 000000000000019a   R8: 0000000000000040   R9: ffff94ca41b82200
> >      R10: ffffffffffffffcf  R11: 0000000000000001  R12: 0000000000000001
> >      R13: 0000000000000001  R14: ffffffffffffffcf  R15: 000000000000005f
> >      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
> >   #7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm]
> >   #8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm]
> >   #9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm]
> > #10 [ffffb1ba6707ff10] __x64_sys_ioctl at ffffffff85935474
> > #11 [ffffb1ba6707ff40] do_syscall_64 at ffffffff85f921d3
> > #12 [ffffb1ba6707ff50] entry_SYSCALL_64_after_hwframe at ffffffff8600007c
> >      RIP: 00007f143c36488b  RSP: 00007f143a4e04b8  RFLAGS: 00000246
> >      RAX: ffffffffffffffda  RBX: 00007f05780041d0  RCX: 00007f143c36488b
> >      RDX: 00007f05780041d0  RSI: 000000004008ae6a  RDI: 0000000000000020
> >      RBP: 00000000000004e8   R8: 0000000000000008   R9: 00007f05780041e0
> >      R10: 00007f0578004560  R11: 0000000000000246  R12: 00000000000004e0
> >      R13: 000000000000001a  R14: 00007f1424001c60  R15: 00007f0578003bc0
> >      ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b
> > 
> > Vmx have been fix this in commit 3a8b0677fc61 (KVM: VMX: Do not BUG() on
> > out-of-bounds guest IRQ), so we can just copy source from that to fix
> > this.
> > 
> > Signed-off-by: Yi Wang <wang.yi59@xxxxxxxxxx>
> > Signed-off-by: Yi Liu <liu.yi24@xxxxxxxxxx>
> 
> Hi, the Signed-off-by chain is wrong.  Did Yi Liu write the patch (and 
> you are just sending it)?

The Signed-off-by chain is not wrong, I (Yi Wang) wrote this patch and Yi Liu
co-developed it.

> 
> Paolo