diff mbox series

[v3,3/3] hw/smbios: add assertion to ensure handles of tables 19 and 32 do not collide

Message ID 20220214141237.47946-4-ani@anisinha.ca
State New
Headers show
Series hw/smbios: fix table memory corruption with large memory vms | expand

Commit Message

Ani Sinha Feb. 14, 2022, 2:12 p.m. UTC
Since change b3cddba9c14b034 ("hw/smbios: fix table memory corruption with large memory vms")
we reserve additional space between handle numbers of tables 17 and 19 for
large VMs. This may cause table 19 to collide with table 32 in their handle
numbers for those large VMs. This change adds an assertion to ensure numbers
do not collide. If they do, qemu crashes with useful debug information for
taking additional steps.

Signed-off-by: Ani Sinha <ani@anisinha.ca>
---
 hw/smbios/smbios.c | 6 ++++++
 1 file changed, 6 insertions(+)

changelog:
v3: reworded the commit log and comment in code.

Comments

Igor Mammedov Feb. 17, 2022, 8:56 a.m. UTC | #1
On Mon, 14 Feb 2022 19:42:36 +0530
Ani Sinha <ani@anisinha.ca> wrote:

> Since change b3cddba9c14b034 ("hw/smbios: fix table memory corruption with large memory vms")
> we reserve additional space between handle numbers of tables 17 and 19 for
> large VMs. This may cause table 19 to collide with table 32 in their handle
> numbers for those large VMs. This change adds an assertion to ensure numbers
> do not collide. If they do, qemu crashes with useful debug information for
> taking additional steps.
> 
> Signed-off-by: Ani Sinha <ani@anisinha.ca>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/smbios/smbios.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> changelog:
> v3: reworded the commit log and comment in code.
> 
> diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
> index 44c53797a4..1f8d5c252f 100644
> --- a/hw/smbios/smbios.c
> +++ b/hw/smbios/smbios.c
> @@ -1048,6 +1048,12 @@ void smbios_get_tables(MachineState *ms,
>                                         mem_array[i].length);
>          }
>  
> +        /*
> +         * make sure 16 bit handle numbers in the headers of tables 19
> +         * and 32 do not overlap.
> +         */
> +        assert((mem_array_size + offset) < (T32_BASE - T19_BASE));
> +
>          smbios_build_type_32_table();
>          smbios_build_type_38_table();
>          smbios_build_type_41_table(errp);
diff mbox series

Patch

diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index 44c53797a4..1f8d5c252f 100644
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -1048,6 +1048,12 @@  void smbios_get_tables(MachineState *ms,
                                        mem_array[i].length);
         }
 
+        /*
+         * make sure 16 bit handle numbers in the headers of tables 19
+         * and 32 do not overlap.
+         */
+        assert((mem_array_size + offset) < (T32_BASE - T19_BASE));
+
         smbios_build_type_32_table();
         smbios_build_type_38_table();
         smbios_build_type_41_table(errp);