This is a note to let you know that I've just added the patch titled
efi: fix userspace infinite retry read efivars after EFI runtime services page fault
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-fix-userspace-infinite-retry-read-efivars-after-efi-runtime-services-page-fault.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e006ac3003080177cf0b673441a4241f77aaecce Mon Sep 17 00:00:00 2001
From: Ding Hui <dinghui@xxxxxxxxxxxxxx>
Date: Tue, 27 Dec 2022 23:09:36 +0800
Subject: efi: fix userspace infinite retry read efivars after EFI runtime services page fault
From: Ding Hui <dinghui@xxxxxxxxxxxxxx>
commit e006ac3003080177cf0b673441a4241f77aaecce upstream.
After [1][2], if we catch exceptions due to EFI runtime service, we will
clear EFI_RUNTIME_SERVICES bit to disable EFI runtime service, then the
subsequent routine which invoke the EFI runtime service should fail.
But the userspace cat efivars through /sys/firmware/efi/efivars/ will stuck
and infinite loop calling read() due to efivarfs_file_read() return -EINTR.
The -EINTR is converted from EFI_ABORTED by efi_status_to_err(), and is
an improper return value in this situation, so let virt_efi_xxx() return
EFI_DEVICE_ERROR and converted to -EIO to invoker.
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 3425d934fc03 ("efi/x86: Handle page faults occurring while running EFI runtime services")
Fixes: 23715a26c8d8 ("arm64: efi: Recover from synchronous exceptions occurring in firmware")
Signed-off-by: Ding Hui <dinghui@xxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/firmware/efi/runtime-wrappers.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index 7feee3d9c2bf..1fba4e09cdcf 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -62,6 +62,7 @@ struct efi_runtime_work efi_rts_work;
\
if (!efi_enabled(EFI_RUNTIME_SERVICES)) { \
pr_warn_once("EFI Runtime Services are disabled!\n"); \
+ efi_rts_work.status = EFI_DEVICE_ERROR; \
goto exit; \
} \
\
--
2.39.0
Patches currently in stable-queue which might be from dinghui@xxxxxxxxxxxxxx are
queue-6.1/efi-fix-userspace-infinite-retry-read-efivars-after-efi-runtime-services-page-fault.patch
