[PATCH] ACPI: APEI: Fix num_ghes to unsigned int

[PATCH] ACPI: APEI: Fix num_ghes to unsigned int

[Ashish Kalra]

From: Ashish Kalra <ashish.kalra@amd.com>

Change num_ghes from int to unsigned int, preventing an overflow
and causing subsequent vmalloc to fail.

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 drivers/acpi/apei/ghes.c | 2 +-
 include/acpi/ghes.h      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index d91ad378c00d..6d7c202142a6 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -163,7 +163,7 @@ static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
 	clear_fixmap(fixmap_idx);
 }
 
-int ghes_estatus_pool_init(int num_ghes)
+int ghes_estatus_pool_init(unsigned int num_ghes)
 {
 	unsigned long addr, len;
 	int rc;
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 34fb3431a8f3..292a5c40bd0c 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -71,7 +71,7 @@ int ghes_register_vendor_record_notifier(struct notifier_block *nb);
 void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
 #endif
 
-int ghes_estatus_pool_init(int num_ghes);
+int ghes_estatus_pool_init(unsigned int num_ghes);
 
 /* From drivers/edac/ghes_edac.c */
 
-- 
2.25.1

Re: [PATCH] ACPI: APEI: Fix num_ghes to unsigned int

[Rafael J. Wysocki]

On Wed, Oct 5, 2022 at 1:06 AM Ashish Kalra <Ashish.Kalra@amd.com> wrote:
>
> From: Ashish Kalra <ashish.kalra@amd.com>
>
> Change num_ghes from int to unsigned int, preventing an overflow
> and causing subsequent vmalloc to fail.

So do you have a system where int is not sufficient?

> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> ---
>  drivers/acpi/apei/ghes.c | 2 +-
>  include/acpi/ghes.h      | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index d91ad378c00d..6d7c202142a6 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -163,7 +163,7 @@ static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
>         clear_fixmap(fixmap_idx);
>  }
>
> -int ghes_estatus_pool_init(int num_ghes)
> +int ghes_estatus_pool_init(unsigned int num_ghes)
>  {
>         unsigned long addr, len;
>         int rc;
> diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
> index 34fb3431a8f3..292a5c40bd0c 100644
> --- a/include/acpi/ghes.h
> +++ b/include/acpi/ghes.h
> @@ -71,7 +71,7 @@ int ghes_register_vendor_record_notifier(struct notifier_block *nb);
>  void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
>  #endif
>
> -int ghes_estatus_pool_init(int num_ghes);
> +int ghes_estatus_pool_init(unsigned int num_ghes);
>
>  /* From drivers/edac/ghes_edac.c */
>
> --
> 2.25.1
>

[PATCH] ACPI: APEI: Fix num_ghes to unsigned int

[Ashish Kalra]

Yes, on one of our AMD EPYC processors, num_ghes is 32776 and we get the following call trace due to vmalloc() failure beacuse of the overflow:

[    9.317108] swapper/0: vmalloc error: size 18446744071562596352, exceeds total pages, mode:0xcc0(GFP_KERNEL), nodemask=(null),cpuset=/,mems_allowed=0-1
[    9.317125] CPU: 256 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc6-snp-host-61a51248451b #1
[    9.317129] Hardware name: AMD Corporation QUARTZ/QUARTZ, BIOS TQZ1002E 09/28/2022
[    9.317131] Call Trace:
[    9.317134]  <TASK>
[    9.317137]  dump_stack_lvl+0x49/0x5f
[    9.317145]  dump_stack+0x10/0x12
[    9.317146]  warn_alloc.cold+0x7b/0xdf
[    9.317150]  ? __device_attach+0x16a/0x1b0
[    9.317155]  __vmalloc_node_range+0x702/0x740
[    9.317160]  ? device_add+0x17f/0x920
[    9.317164]  ? dev_set_name+0x53/0x70
[    9.317166]  ? platform_device_add+0xf9/0x240
[    9.317168]  __vmalloc_node+0x49/0x50
[    9.317170]  ? ghes_estatus_pool_init+0x43/0xa0
[    9.317176]  vmalloc+0x21/0x30
[    9.317177]  ghes_estatus_pool_init+0x43/0xa0
[    9.317179]  acpi_hest_init+0x129/0x19c
[    9.317185]  acpi_init+0x434/0x4a4
[    9.317188]  ? acpi_sleep_proc_init+0x2a/0x2a
[    9.317190]  do_one_initcall+0x48/0x200
[    9.317195]  kernel_init_freeable+0x221/0x284
[    9.317200]  ? rest_init+0xe0/0xe0
[    9.317204]  kernel_init+0x1a/0x130
[    9.317205]  ret_from_fork+0x22/0x30
[    9.317208]  </TASK>

Thanks,
Ashish

Re: [PATCH] ACPI: APEI: Fix num_ghes to unsigned int

[Rafael J. Wysocki]

On Wed, Oct 5, 2022 at 5:41 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote:
>
> Yes, on one of our AMD EPYC processors, num_ghes is 32776 and we get the following call trace due to vmalloc() failure beacuse of the overflow:

But int should be more than sufficient to accommodate that number.

I think that the overflow takes place during the execution of this statement:

len += (num_ghes * GHES_ESOURCE_PREALLOC_MAX_SIZE);

because the right-hand side of it is of type int, because both
multiplication operands are int.

You should say that in the changelog.