* [PATCH] efi: fix panic in kdump kernel
@ 2024-03-22 1:08 Oleksandr Tymoshenko
2024-03-22 8:00 ` Johan Hovold
0 siblings, 1 reply; 2+ messages in thread
From: Oleksandr Tymoshenko @ 2024-03-22 1:08 UTC (permalink / raw)
To: Ard Biesheuvel; +Cc: ovt, johan+linaro, linux-efi, linux-kernel
Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.
Tested with QEMU and OVMF firmware.
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
---
drivers/firmware/efi/efi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 8859fb0b006d..800b85807a02 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -203,6 +203,8 @@ static bool generic_ops_supported(void)
name_size = sizeof(name);
+ if (efi.get_next_variable == NULL)
+ return false;
status = efi.get_next_variable(&name_size, &name, &guid);
if (status == EFI_UNSUPPORTED)
return false;
--
2.44.0.396.g6e790dbe36-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] efi: fix panic in kdump kernel
2024-03-22 1:08 [PATCH] efi: fix panic in kdump kernel Oleksandr Tymoshenko
@ 2024-03-22 8:00 ` Johan Hovold
0 siblings, 0 replies; 2+ messages in thread
From: Johan Hovold @ 2024-03-22 8:00 UTC (permalink / raw)
To: Oleksandr Tymoshenko
Cc: Ard Biesheuvel, johan+linaro, linux-efi, linux-kernel
On Fri, Mar 22, 2024 at 01:08:45AM +0000, Oleksandr Tymoshenko wrote:
> Check if get_next_variable() is actually valid pointer before
> calling it. In kdump kernel this method is set to NULL that causes
> panic during the kexec-ed kernel boot.
>
> Tested with QEMU and OVMF firmware.
Sounds like you want a Fixes and CC stable tag here as well.
> Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
> ---
> drivers/firmware/efi/efi.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 8859fb0b006d..800b85807a02 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -203,6 +203,8 @@ static bool generic_ops_supported(void)
>
> name_size = sizeof(name);
>
> + if (efi.get_next_variable == NULL)
> + return false;
Please move this check above the name_size initialisation and make sure
you have a new line before and after.
I'd also suggest rewriting this as:
if (!efi.get_next_variable)
return false;
> status = efi.get_next_variable(&name_size, &name, &guid);
> if (status == EFI_UNSUPPORTED)
> return false;
Johan
^ permalink raw reply [flat|nested] 2+ messages in thread
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2024-03-22 8:00 ` Johan Hovold
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