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[PATCH 08/11] virtio-net: Fix duplex=... and speed=... error handling

Markus Armbruster posted 11 patches 5 years, 9 months ago
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <rth@twiddle.net>, Kevin Wolf <kwolf@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Jason Wang <jasowang@redhat.com>, Anthony Perard <anthony.perard@citrix.com>, Stefano Stabellini <sstabellini@kernel.org>, John Snow <jsnow@redhat.com>, Paul Durrant <paul@xen.org>, Juan Quintela <quintela@redhat.com>, Hailiang Zhang <zhang.zhanghailiang@huawei.com>, Max Reitz <mreitz@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, "Gonglei (Arei)" <arei.gonglei@huawei.com>
There is a newer version of this series
[PATCH 08/11] virtio-net: Fix duplex=... and speed=... error handling
Posted by Markus Armbruster 5 years, 9 months ago 
virtio_net_device_realize() rejects invalid duplex and speed values.
The error handling is broken:

    $ ../qemu/bld-sani/x86_64-softmmu/qemu-system-x86_64 -S -display none -monitor stdio
    QEMU 4.2.93 monitor - type 'help' for more information
    (qemu) device_add virtio-net,duplex=x
    Error: 'duplex' must be 'half' or 'full'
    (qemu) c
    =================================================================
    ==15654==ERROR: AddressSanitizer: heap-use-after-free on address 0x62e000014590 at pc 0x560b75c8dc13 bp 0x7fffdf1a6950 sp 0x7fffdf1a6940
    READ of size 8 at 0x62e000014590 thread T0
	#0 0x560b75c8dc12 in object_dynamic_cast_assert /work/armbru/qemu/qom/object.c:826
	#1 0x560b74c38ac0 in virtio_vmstate_change /work/armbru/qemu/hw/virtio/virtio.c:3210
	#2 0x560b74d9765e in vm_state_notify /work/armbru/qemu/softmmu/vl.c:1271
	#3 0x560b7494ba72 in vm_prepare_start /work/armbru/qemu/cpus.c:2156
	#4 0x560b7494bacd in vm_start /work/armbru/qemu/cpus.c:2162
	#5 0x560b75a7d890 in qmp_cont /work/armbru/qemu/monitor/qmp-cmds.c:160
	#6 0x560b75a8d70a in hmp_cont /work/armbru/qemu/monitor/hmp-cmds.c:1043
	#7 0x560b75a799f2 in handle_hmp_command /work/armbru/qemu/monitor/hmp.c:1082
    [...]

    0x62e000014590 is located 33168 bytes inside of 42288-byte region [0x62e00000c400,0x62e000016930)
    freed by thread T1 here:
	#0 0x7feadd39491f in __interceptor_free (/lib64/libasan.so.5+0x10d91f)
	#1 0x7feadcebcd7c in g_free (/lib64/libglib-2.0.so.0+0x55d7c)
	#2 0x560b75c8fd40 in object_unref /work/armbru/qemu/qom/object.c:1128
	#3 0x560b7498a625 in memory_region_unref /work/armbru/qemu/memory.c:1762
	#4 0x560b74999fa4 in do_address_space_destroy /work/armbru/qemu/memory.c:2788
	#5 0x560b762362fc in call_rcu_thread /work/armbru/qemu/util/rcu.c:283
	#6 0x560b761c8884 in qemu_thread_start /work/armbru/qemu/util/qemu-thread-posix.c:519
	#7 0x7fead9be34bf in start_thread (/lib64/libpthread.so.0+0x84bf)

    previously allocated by thread T0 here:
	#0 0x7feadd394d18 in __interceptor_malloc (/lib64/libasan.so.5+0x10dd18)
	#1 0x7feadcebcc88 in g_malloc (/lib64/libglib-2.0.so.0+0x55c88)
	#2 0x560b75c8cf8a in object_new /work/armbru/qemu/qom/object.c:699
	#3 0x560b75010ad9 in qdev_device_add /work/armbru/qemu/qdev-monitor.c:654
	#4 0x560b750120c2 in qmp_device_add /work/armbru/qemu/qdev-monitor.c:805
	#5 0x560b75012c1b in hmp_device_add /work/armbru/qemu/qdev-monitor.c:905
    [...]
    ==15654==ABORTING

Cause: virtio_net_device_realize() neglects to bail out after setting
the error.  Fix that.

Fixes: 9473939ed7addcaaeb8fde5c093918fb7fa0919c
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 hw/net/virtio-net.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index a46e3b37a7..b52ff4ab63 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -2947,6 +2947,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
             n->net_conf.duplex = DUPLEX_FULL;
         } else {
             error_setg(errp, "'duplex' must be 'half' or 'full'");
+            return;
         }
         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
     } else {
@@ -2955,7 +2956,9 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
 
     if (n->net_conf.speed < SPEED_UNKNOWN) {
         error_setg(errp, "'speed' must be between 0 and INT_MAX");
-    } else if (n->net_conf.speed >= 0) {
+        return;
+    }
+    if (n->net_conf.speed >= 0) {
         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
     }
 
-- 
2.21.1
Re: [PATCH 08/11] virtio-net: Fix duplex=... and speed=... error handling
Posted by Philippe Mathieu-Daudé 5 years, 9 months ago 
On 4/20/20 10:32 AM, Markus Armbruster wrote:
> virtio_net_device_realize() rejects invalid duplex and speed values.
> The error handling is broken:
> 
>      $ ../qemu/bld-sani/x86_64-softmmu/qemu-system-x86_64 -S -display none -monitor stdio
>      QEMU 4.2.93 monitor - type 'help' for more information
>      (qemu) device_add virtio-net,duplex=x
>      Error: 'duplex' must be 'half' or 'full'
>      (qemu) c
>      =================================================================
>      ==15654==ERROR: AddressSanitizer: heap-use-after-free on address 0x62e000014590 at pc 0x560b75c8dc13 bp 0x7fffdf1a6950 sp 0x7fffdf1a6940
>      READ of size 8 at 0x62e000014590 thread T0
> 	#0 0x560b75c8dc12 in object_dynamic_cast_assert /work/armbru/qemu/qom/object.c:826
> 	#1 0x560b74c38ac0 in virtio_vmstate_change /work/armbru/qemu/hw/virtio/virtio.c:3210
> 	#2 0x560b74d9765e in vm_state_notify /work/armbru/qemu/softmmu/vl.c:1271
> 	#3 0x560b7494ba72 in vm_prepare_start /work/armbru/qemu/cpus.c:2156
> 	#4 0x560b7494bacd in vm_start /work/armbru/qemu/cpus.c:2162
> 	#5 0x560b75a7d890 in qmp_cont /work/armbru/qemu/monitor/qmp-cmds.c:160
> 	#6 0x560b75a8d70a in hmp_cont /work/armbru/qemu/monitor/hmp-cmds.c:1043
> 	#7 0x560b75a799f2 in handle_hmp_command /work/armbru/qemu/monitor/hmp.c:1082
>      [...]
> 
>      0x62e000014590 is located 33168 bytes inside of 42288-byte region [0x62e00000c400,0x62e000016930)
>      freed by thread T1 here:
> 	#0 0x7feadd39491f in __interceptor_free (/lib64/libasan.so.5+0x10d91f)
> 	#1 0x7feadcebcd7c in g_free (/lib64/libglib-2.0.so.0+0x55d7c)
> 	#2 0x560b75c8fd40 in object_unref /work/armbru/qemu/qom/object.c:1128
> 	#3 0x560b7498a625 in memory_region_unref /work/armbru/qemu/memory.c:1762
> 	#4 0x560b74999fa4 in do_address_space_destroy /work/armbru/qemu/memory.c:2788
> 	#5 0x560b762362fc in call_rcu_thread /work/armbru/qemu/util/rcu.c:283
> 	#6 0x560b761c8884 in qemu_thread_start /work/armbru/qemu/util/qemu-thread-posix.c:519
> 	#7 0x7fead9be34bf in start_thread (/lib64/libpthread.so.0+0x84bf)
> 
>      previously allocated by thread T0 here:
> 	#0 0x7feadd394d18 in __interceptor_malloc (/lib64/libasan.so.5+0x10dd18)
> 	#1 0x7feadcebcc88 in g_malloc (/lib64/libglib-2.0.so.0+0x55c88)
> 	#2 0x560b75c8cf8a in object_new /work/armbru/qemu/qom/object.c:699
> 	#3 0x560b75010ad9 in qdev_device_add /work/armbru/qemu/qdev-monitor.c:654
> 	#4 0x560b750120c2 in qmp_device_add /work/armbru/qemu/qdev-monitor.c:805
> 	#5 0x560b75012c1b in hmp_device_add /work/armbru/qemu/qdev-monitor.c:905
>      [...]
>      ==15654==ABORTING
> 
> Cause: virtio_net_device_realize() neglects to bail out after setting
> the error.  Fix that.
> 
> Fixes: 9473939ed7addcaaeb8fde5c093918fb7fa0919c
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   hw/net/virtio-net.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index a46e3b37a7..b52ff4ab63 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -2947,6 +2947,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
>               n->net_conf.duplex = DUPLEX_FULL;
>           } else {
>               error_setg(errp, "'duplex' must be 'half' or 'full'");
> +            return;
>           }
>           n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
>       } else {
> @@ -2955,7 +2956,9 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
>   
>       if (n->net_conf.speed < SPEED_UNKNOWN) {
>           error_setg(errp, "'speed' must be between 0 and INT_MAX");
> -    } else if (n->net_conf.speed >= 0) {
> +        return;
> +    }
> +    if (n->net_conf.speed >= 0) {
>           n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
>       }
>   
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Patchew 2.1-devel-b67e4c2

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