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[PATCH v2] hw/acpi/erst.c: Fix memory handling issues

Christian A. Ehrhardt posted 1 patch 3 years, 3 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20221024154233.1043347-1-lk@c--e.de
Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Ani Sinha <ani@anisinha.ca>
hw/acpi/erst.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
[PATCH v2] hw/acpi/erst.c: Fix memory handling issues
Posted by Christian A. Ehrhardt 3 years, 3 months ago 
- Fix memset argument order: The second argument is
  the value, the length goes last.
- Fix an integer overflow reported by Alexander Bulekov.

Both issues allow the guest to overrun the host buffer
allocated for the ERST memory device.

Cc: Eric DeVolder <eric.devolder@oracle.com
Cc: Alexander Bulekov <alxndr@bu.edu>
Cc: qemu-stable@nongnu.org
Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
Tested-by: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
---
 hw/acpi/erst.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
index df856b2669..aefcc03ad6 100644
--- a/hw/acpi/erst.c
+++ b/hw/acpi/erst.c
@@ -635,7 +635,7 @@ static unsigned read_erst_record(ERSTDeviceState *s)
         if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
             rc = STATUS_FAILED;
         }
-        if ((s->record_offset + record_length) > exchange_length) {
+        if (record_length > exchange_length - s->record_offset) {
             rc = STATUS_FAILED;
         }
         /* If all is ok, copy the record to the exchange buffer */
@@ -684,7 +684,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
     if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
         return STATUS_FAILED;
     }
-    if ((s->record_offset + record_length) > exchange_length) {
+    if (record_length > exchange_length - s->record_offset) {
         return STATUS_FAILED;
     }
 
@@ -716,7 +716,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
     if (nvram) {
         /* Write the record into the slot */
         memcpy(nvram, exchange, record_length);
-        memset(nvram + record_length, exchange_length - record_length, 0xFF);
+        memset(nvram + record_length, 0xFF, exchange_length - record_length);
         /* If a new record, increment the record_count */
         if (!record_found) {
             uint32_t record_count;
-- 
2.34.1
Re: [PATCH v2] hw/acpi/erst.c: Fix memory handling issues
Posted by Eric DeVolder 3 years, 3 months ago 

On 10/24/22 10:42, Christian A. Ehrhardt wrote:
> - Fix memset argument order: The second argument is
>    the value, the length goes last.
> - Fix an integer overflow reported by Alexander Bulekov.
> 
> Both issues allow the guest to overrun the host buffer
> allocated for the ERST memory device.
> 
> Cc: Eric DeVolder <eric.devolder@oracle.com
> Cc: Alexander Bulekov <alxndr@bu.edu>
> Cc: qemu-stable@nongnu.org
> Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
> Tested-by: Alexander Bulekov <alxndr@bu.edu>
> Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>

Reviewed-by: Eric DeVolder <eric.devolder@oracle.com>

Thanks Christian!
eric

> ---
>   hw/acpi/erst.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> index df856b2669..aefcc03ad6 100644
> --- a/hw/acpi/erst.c
> +++ b/hw/acpi/erst.c
> @@ -635,7 +635,7 @@ static unsigned read_erst_record(ERSTDeviceState *s)
>           if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
>               rc = STATUS_FAILED;
>           }
> -        if ((s->record_offset + record_length) > exchange_length) {
> +        if (record_length > exchange_length - s->record_offset) {
>               rc = STATUS_FAILED;
>           }
>           /* If all is ok, copy the record to the exchange buffer */
> @@ -684,7 +684,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
>       if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
>           return STATUS_FAILED;
>       }
> -    if ((s->record_offset + record_length) > exchange_length) {
> +    if (record_length > exchange_length - s->record_offset) {
>           return STATUS_FAILED;
>       }
>   
> @@ -716,7 +716,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
>       if (nvram) {
>           /* Write the record into the slot */
>           memcpy(nvram, exchange, record_length);
> -        memset(nvram + record_length, exchange_length - record_length, 0xFF);
> +        memset(nvram + record_length, 0xFF, exchange_length - record_length);
>           /* If a new record, increment the record_count */
>           if (!record_found) {
>               uint32_t record_count;
>
Re: [PATCH v2] hw/acpi/erst.c: Fix memory handling issues
Posted by Michael S. Tsirkin 3 years, 3 months ago 
On Mon, Oct 24, 2022 at 05:42:33PM +0200, Christian A. Ehrhardt wrote:
> - Fix memset argument order: The second argument is
>   the value, the length goes last.
> - Fix an integer overflow reported by Alexander Bulekov.
> 
> Both issues allow the guest to overrun the host buffer
> allocated for the ERST memory device.
> 
> Cc: Eric DeVolder <eric.devolder@oracle.com
> Cc: Alexander Bulekov <alxndr@bu.edu>
> Cc: qemu-stable@nongnu.org
> Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
> Tested-by: Alexander Bulekov <alxndr@bu.edu>
> Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>


queued, thanks!

> ---
>  hw/acpi/erst.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> index df856b2669..aefcc03ad6 100644
> --- a/hw/acpi/erst.c
> +++ b/hw/acpi/erst.c
> @@ -635,7 +635,7 @@ static unsigned read_erst_record(ERSTDeviceState *s)
>          if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
>              rc = STATUS_FAILED;
>          }
> -        if ((s->record_offset + record_length) > exchange_length) {
> +        if (record_length > exchange_length - s->record_offset) {
>              rc = STATUS_FAILED;
>          }
>          /* If all is ok, copy the record to the exchange buffer */
> @@ -684,7 +684,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
>      if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
>          return STATUS_FAILED;
>      }
> -    if ((s->record_offset + record_length) > exchange_length) {
> +    if (record_length > exchange_length - s->record_offset) {
>          return STATUS_FAILED;
>      }
>  
> @@ -716,7 +716,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
>      if (nvram) {
>          /* Write the record into the slot */
>          memcpy(nvram, exchange, record_length);
> -        memset(nvram + record_length, exchange_length - record_length, 0xFF);
> +        memset(nvram + record_length, 0xFF, exchange_length - record_length);
>          /* If a new record, increment the record_count */
>          if (!record_found) {
>              uint32_t record_count;
> -- 
> 2.34.1
Re: [PATCH v2] hw/acpi/erst.c: Fix memory handling issues
Posted by Alexander Bulekov 3 years, 3 months ago 
On 221024 1742, Christian A. Ehrhardt wrote:
> - Fix memset argument order: The second argument is
>   the value, the length goes last.
> - Fix an integer overflow reported by Alexander Bulekov.
> 
> Both issues allow the guest to overrun the host buffer
> allocated for the ERST memory device.
> 
> Cc: Eric DeVolder <eric.devolder@oracle.com
> Cc: Alexander Bulekov <alxndr@bu.edu>
> Cc: qemu-stable@nongnu.org
> Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
> Tested-by: Alexander Bulekov <alxndr@bu.edu>

Reviewed-by: Alexander Bulekov <alxndr@bu.edu>

> Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
> ---
>  hw/acpi/erst.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> index df856b2669..aefcc03ad6 100644
> --- a/hw/acpi/erst.c
> +++ b/hw/acpi/erst.c
> @@ -635,7 +635,7 @@ static unsigned read_erst_record(ERSTDeviceState *s)
>          if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
>              rc = STATUS_FAILED;
>          }
> -        if ((s->record_offset + record_length) > exchange_length) {
> +        if (record_length > exchange_length - s->record_offset) {
>              rc = STATUS_FAILED;
>          }
>          /* If all is ok, copy the record to the exchange buffer */
> @@ -684,7 +684,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
>      if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
>          return STATUS_FAILED;
>      }
> -    if ((s->record_offset + record_length) > exchange_length) {
> +    if (record_length > exchange_length - s->record_offset) {
>          return STATUS_FAILED;
>      }
>  
> @@ -716,7 +716,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
>      if (nvram) {
>          /* Write the record into the slot */
>          memcpy(nvram, exchange, record_length);
> -        memset(nvram + record_length, exchange_length - record_length, 0xFF);
> +        memset(nvram + record_length, 0xFF, exchange_length - record_length);
>          /* If a new record, increment the record_count */
>          if (!record_found) {
>              uint32_t record_count;
> -- 
> 2.34.1
> 
>
Re: [PATCH v2] hw/acpi/erst.c: Fix memory handling issues
Posted by Alexander Bulekov 3 years, 3 months ago 
On 221024 1224, Alexander Bulekov wrote:
> On 221024 1742, Christian A. Ehrhardt wrote:
> > - Fix memset argument order: The second argument is
> >   the value, the length goes last.
> > - Fix an integer overflow reported by Alexander Bulekov.
> > 
> > Both issues allow the guest to overrun the host buffer
> > allocated for the ERST memory device.
> > 
> > Cc: Eric DeVolder <eric.devolder@oracle.com
> > Cc: Alexander Bulekov <alxndr@bu.edu>
> > Cc: qemu-stable@nongnu.org
> > Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
> > Tested-by: Alexander Bulekov <alxndr@bu.edu>
> 

Also:
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1268

> Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
> 
> > Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
> > ---
> >  hw/acpi/erst.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> > index df856b2669..aefcc03ad6 100644
> > --- a/hw/acpi/erst.c
> > +++ b/hw/acpi/erst.c
> > @@ -635,7 +635,7 @@ static unsigned read_erst_record(ERSTDeviceState *s)
> >          if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
> >              rc = STATUS_FAILED;
> >          }
> > -        if ((s->record_offset + record_length) > exchange_length) {
> > +        if (record_length > exchange_length - s->record_offset) {
> >              rc = STATUS_FAILED;
> >          }
> >          /* If all is ok, copy the record to the exchange buffer */
> > @@ -684,7 +684,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
> >      if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
> >          return STATUS_FAILED;
> >      }
> > -    if ((s->record_offset + record_length) > exchange_length) {
> > +    if (record_length > exchange_length - s->record_offset) {
> >          return STATUS_FAILED;
> >      }
> >  
> > @@ -716,7 +716,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
> >      if (nvram) {
> >          /* Write the record into the slot */
> >          memcpy(nvram, exchange, record_length);
> > -        memset(nvram + record_length, exchange_length - record_length, 0xFF);
> > +        memset(nvram + record_length, 0xFF, exchange_length - record_length);
> >          /* If a new record, increment the record_count */
> >          if (!record_found) {
> >              uint32_t record_count;
> > -- 
> > 2.34.1
> > 
> >

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