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 5.10-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-.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7806a2d37dd3220a1aa94e587bd5b0ca2958f951 Author: Ding Hui <dinghui@xxxxxxxxxxxxxx> Date: Tue Dec 27 23:09:36 2022 +0800 efi: fix userspace infinite retry read efivars after EFI runtime services page fault [ Upstream commit e006ac3003080177cf0b673441a4241f77aaecce ] 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: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index f3e54f6616f0..60075e0e4943 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; \ } \ \