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[Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast

Li Qiang posted 1 patch 4 years, 10 months ago
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git fetch https://github.com/patchew-project/qemu tags/patchew/20190622002119.126834-1-liq3ea@163.com
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>
hw/intc/ioapic.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
[Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast
Posted by Li Qiang 4 years, 10 months ago 
When emulating irqchip in qemu, such as following command:

x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img
-machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor stdio

We will get a crash with following asan output:

(qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error: index 35 out of bounds for type 'int [24]'
=================================================================
==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00
WRITE of size 4 at 0x61b000003114 thread T4
    #0 0x5579e3c7a80e in ioapic_eoi_broadcast /home/test/qemu5/qemu/hw/intc/ioapic.c:266
    #1 0x5579e3c6f480 in apic_eoi /home/test/qemu5/qemu/hw/intc/apic.c:428
    #2 0x5579e3c720a7 in apic_mem_write /home/test/qemu5/qemu/hw/intc/apic.c:802
    #3 0x5579e3b1e31a in memory_region_write_accessor /home/test/qemu5/qemu/memory.c:503
    #4 0x5579e3b1e6a2 in access_with_adjusted_size /home/test/qemu5/qemu/memory.c:569
    #5 0x5579e3b28d77 in memory_region_dispatch_write /home/test/qemu5/qemu/memory.c:1497
    #6 0x5579e3a1b36b in flatview_write_continue /home/test/qemu5/qemu/exec.c:3323
    #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362
    #8 0x5579e3a1bcb1 in address_space_write /home/test/qemu5/qemu/exec.c:3452
    #9 0x5579e3a1bd03 in address_space_rw /home/test/qemu5/qemu/exec.c:3463
    #10 0x5579e3b8b979 in kvm_cpu_exec /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045
    #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn /home/test/qemu5/qemu/cpus.c:1287
    #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502
    #13 0x7fd0146376da in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)
    #14 0x7fd01436088e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x12188e

This is because in ioapic_eoi_broadcast function, we uses 'vector' to
index the 's->irq_eoi'. To fix this, we should uses the irq number.

Signed-off-by: Li Qiang <liq3ea@163.com>
---
Change since v1:
remove auto-generated unnecessary message

 hw/intc/ioapic.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
index 7074489fdf..711775cc6f 100644
--- a/hw/intc/ioapic.c
+++ b/hw/intc/ioapic.c
@@ -245,8 +245,8 @@ void ioapic_eoi_broadcast(int vector)
             s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
 
             if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
-                ++s->irq_eoi[vector];
-                if (s->irq_eoi[vector] >= SUCCESSIVE_IRQ_MAX_COUNT) {
+                ++s->irq_eoi[n];
+                if (s->irq_eoi[n] >= SUCCESSIVE_IRQ_MAX_COUNT) {
                     /*
                      * Real hardware does not deliver the interrupt immediately
                      * during eoi broadcast, and this lets a buggy guest make
@@ -254,16 +254,16 @@ void ioapic_eoi_broadcast(int vector)
                      * level-triggered interrupt. Emulate this behavior if we
                      * detect an interrupt storm.
                      */
-                    s->irq_eoi[vector] = 0;
+                    s->irq_eoi[n] = 0;
                     timer_mod_anticipate(s->delayed_ioapic_service_timer,
                                          qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
                                          NANOSECONDS_PER_SECOND / 100);
-                    trace_ioapic_eoi_delayed_reassert(vector);
+                    trace_ioapic_eoi_delayed_reassert(n);
                 } else {
                     ioapic_service(s);
                 }
             } else {
-                s->irq_eoi[vector] = 0;
+                s->irq_eoi[n] = 0;
             }
         }
     }
-- 
2.17.1
Re: [Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast
Posted by Li Qiang 4 years, 10 months ago 
Ping, what's the status of this patch.


Li Qiang <liq3ea@163.com> 于2019年6月22日周六 上午8:21写道：

> When emulating irqchip in qemu, such as following command:
>
> x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img
> -machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor stdio
>
> We will get a crash with following asan output:
>
> (qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error: index
> 35 out of bounds for type 'int [24]'
> =================================================================
> ==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address
> 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00
> WRITE of size 4 at 0x61b000003114 thread T4
>     #0 0x5579e3c7a80e in ioapic_eoi_broadcast
> /home/test/qemu5/qemu/hw/intc/ioapic.c:266
>     #1 0x5579e3c6f480 in apic_eoi /home/test/qemu5/qemu/hw/intc/apic.c:428
>     #2 0x5579e3c720a7 in apic_mem_write
> /home/test/qemu5/qemu/hw/intc/apic.c:802
>     #3 0x5579e3b1e31a in memory_region_write_accessor
> /home/test/qemu5/qemu/memory.c:503
>     #4 0x5579e3b1e6a2 in access_with_adjusted_size
> /home/test/qemu5/qemu/memory.c:569
>     #5 0x5579e3b28d77 in memory_region_dispatch_write
> /home/test/qemu5/qemu/memory.c:1497
>     #6 0x5579e3a1b36b in flatview_write_continue
> /home/test/qemu5/qemu/exec.c:3323
>     #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362
>     #8 0x5579e3a1bcb1 in address_space_write
> /home/test/qemu5/qemu/exec.c:3452
>     #9 0x5579e3a1bd03 in address_space_rw /home/test/qemu5/qemu/exec.c:3463
>     #10 0x5579e3b8b979 in kvm_cpu_exec
> /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045
>     #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn
> /home/test/qemu5/qemu/cpus.c:1287
>     #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502
>     #13 0x7fd0146376da in start_thread
> (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)
>     #14 0x7fd01436088e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x12188e
>
> This is because in ioapic_eoi_broadcast function, we uses 'vector' to
> index the 's->irq_eoi'. To fix this, we should uses the irq number.
>
> Signed-off-by: Li Qiang <liq3ea@163.com>
> ---
> Change since v1:
> remove auto-generated unnecessary message
>
>  hw/intc/ioapic.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
> index 7074489fdf..711775cc6f 100644
> --- a/hw/intc/ioapic.c
> +++ b/hw/intc/ioapic.c
> @@ -245,8 +245,8 @@ void ioapic_eoi_broadcast(int vector)
>              s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
>
>              if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
> -                ++s->irq_eoi[vector];
> -                if (s->irq_eoi[vector] >= SUCCESSIVE_IRQ_MAX_COUNT) {
> +                ++s->irq_eoi[n];
> +                if (s->irq_eoi[n] >= SUCCESSIVE_IRQ_MAX_COUNT) {
>                      /*
>                       * Real hardware does not deliver the interrupt
> immediately
>                       * during eoi broadcast, and this lets a buggy guest
> make
> @@ -254,16 +254,16 @@ void ioapic_eoi_broadcast(int vector)
>                       * level-triggered interrupt. Emulate this behavior
> if we
>                       * detect an interrupt storm.
>                       */
> -                    s->irq_eoi[vector] = 0;
> +                    s->irq_eoi[n] = 0;
>                      timer_mod_anticipate(s->delayed_ioapic_service_timer,
>
> qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
>                                           NANOSECONDS_PER_SECOND / 100);
> -                    trace_ioapic_eoi_delayed_reassert(vector);
> +                    trace_ioapic_eoi_delayed_reassert(n);
>                  } else {
>                      ioapic_service(s);
>                  }
>              } else {
> -                s->irq_eoi[vector] = 0;
> +                s->irq_eoi[n] = 0;
>              }
>          }
>      }
> --
> 2.17.1
>
>
>
Re: [Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast
Posted by Peter Xu 4 years, 10 months ago 
On Fri, Jun 21, 2019 at 05:21:19PM -0700, Li Qiang wrote:
> When emulating irqchip in qemu, such as following command:
> 
> x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img
> -machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor stdio
> 
> We will get a crash with following asan output:
> 
> (qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error: index 35 out of bounds for type 'int [24]'
> =================================================================
> ==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00
> WRITE of size 4 at 0x61b000003114 thread T4
>     #0 0x5579e3c7a80e in ioapic_eoi_broadcast /home/test/qemu5/qemu/hw/intc/ioapic.c:266
>     #1 0x5579e3c6f480 in apic_eoi /home/test/qemu5/qemu/hw/intc/apic.c:428
>     #2 0x5579e3c720a7 in apic_mem_write /home/test/qemu5/qemu/hw/intc/apic.c:802
>     #3 0x5579e3b1e31a in memory_region_write_accessor /home/test/qemu5/qemu/memory.c:503
>     #4 0x5579e3b1e6a2 in access_with_adjusted_size /home/test/qemu5/qemu/memory.c:569
>     #5 0x5579e3b28d77 in memory_region_dispatch_write /home/test/qemu5/qemu/memory.c:1497
>     #6 0x5579e3a1b36b in flatview_write_continue /home/test/qemu5/qemu/exec.c:3323
>     #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362
>     #8 0x5579e3a1bcb1 in address_space_write /home/test/qemu5/qemu/exec.c:3452
>     #9 0x5579e3a1bd03 in address_space_rw /home/test/qemu5/qemu/exec.c:3463
>     #10 0x5579e3b8b979 in kvm_cpu_exec /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045
>     #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn /home/test/qemu5/qemu/cpus.c:1287
>     #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502
>     #13 0x7fd0146376da in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)
>     #14 0x7fd01436088e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x12188e
> 
> This is because in ioapic_eoi_broadcast function, we uses 'vector' to
> index the 's->irq_eoi'. To fix this, we should uses the irq number.
> 
> Signed-off-by: Li Qiang <liq3ea@163.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

Maybe also add:

Fixes: 958a01dab8 ("ioapic: allow buggy guests mishandling ...")

Should we better clear irq_eoi when the entries are updated in
ioapic_mem_write()?

Regards,

-- 
Peter Xu
Re: [Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast
Posted by Li Qiang 4 years, 10 months ago 
Peter Xu <peterx@redhat.com> 于2019年6月24日周一 下午5:42写道：

> On Fri, Jun 21, 2019 at 05:21:19PM -0700, Li Qiang wrote:
> > When emulating irqchip in qemu, such as following command:
> >
> > x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img
> > -machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor
> stdio
> >
> > We will get a crash with following asan output:
> >
> > (qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error:
> index 35 out of bounds for type 'int [24]'
> > =================================================================
> > ==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address
> 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00
> > WRITE of size 4 at 0x61b000003114 thread T4
> >     #0 0x5579e3c7a80e in ioapic_eoi_broadcast
> /home/test/qemu5/qemu/hw/intc/ioapic.c:266
> >     #1 0x5579e3c6f480 in apic_eoi
> /home/test/qemu5/qemu/hw/intc/apic.c:428
> >     #2 0x5579e3c720a7 in apic_mem_write
> /home/test/qemu5/qemu/hw/intc/apic.c:802
> >     #3 0x5579e3b1e31a in memory_region_write_accessor
> /home/test/qemu5/qemu/memory.c:503
> >     #4 0x5579e3b1e6a2 in access_with_adjusted_size
> /home/test/qemu5/qemu/memory.c:569
> >     #5 0x5579e3b28d77 in memory_region_dispatch_write
> /home/test/qemu5/qemu/memory.c:1497
> >     #6 0x5579e3a1b36b in flatview_write_continue
> /home/test/qemu5/qemu/exec.c:3323
> >     #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362
> >     #8 0x5579e3a1bcb1 in address_space_write
> /home/test/qemu5/qemu/exec.c:3452
> >     #9 0x5579e3a1bd03 in address_space_rw
> /home/test/qemu5/qemu/exec.c:3463
> >     #10 0x5579e3b8b979 in kvm_cpu_exec
> /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045
> >     #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn
> /home/test/qemu5/qemu/cpus.c:1287
> >     #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502
> >     #13 0x7fd0146376da in start_thread
> (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)
> >     #14 0x7fd01436088e in __clone
> (/lib/x86_64-linux-gnu/libc.so.6+0x12188e
> >
> > This is because in ioapic_eoi_broadcast function, we uses 'vector' to
> > index the 's->irq_eoi'. To fix this, we should uses the irq number.
> >
> > Signed-off-by: Li Qiang <liq3ea@163.com>
>
> Reviewed-by: Peter Xu <peterx@redhat.com>
>
>
Thanks Peter.



> Maybe also add:
>
> Fixes: 958a01dab8 ("ioapic: allow buggy guests mishandling ...")
>
> Should we better clear irq_eoi when the entries are updated in
> ioapic_mem_write()?
>
>
Do you mean the redirect table entry of ioapic update?
I think this is reasonable, I will prepare a separate patch with this one
as a patchset later.

Thanks,
Li Qiang



> Regards,
>
> --
> Peter Xu
>
Re: [Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast
Posted by Peter Xu 4 years, 10 months ago 
On Mon, Jun 24, 2019 at 07:08:30PM +0800, Li Qiang wrote:
> Do you mean the redirect table entry of ioapic update?

Yes.

> I think this is reasonable, I will prepare a separate patch with this one
> as a patchset later.

IMHO you can post that as separate patch.  After all these are
different issues and this one looks good already, so no need to
repost.

Regards,

-- 
Peter Xu
Re: [Qemu-devel] [PATCH v2] ioapic: use irq number instead of vector in ioapic_eoi_broadcast
Posted by Li Qiang 4 years, 10 months ago 
Peter Xu <peterx@redhat.com> 于2019年6月24日周一 下午7:21写道：

> On Mon, Jun 24, 2019 at 07:08:30PM +0800, Li Qiang wrote:
> > Do you mean the redirect table entry of ioapic update?
>
> Yes.
>
> > I think this is reasonable, I will prepare a separate patch with this one
> > as a patchset later.
>
> IMHO you can post that as separate patch.  After all these are
> different issues and this one looks good already, so no need to
> repost.
>
>

OK, got.

For the maintainer please remember to add the Fixes tag Peter adds in the
review
and also merge the v2 version.


Thanks,
Li Qiang



> Regards,
>
> --
> Peter Xu
>

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