From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82E571F4170; Sun, 24 Mar 2024 22:59:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321150; cv=none; b=aGhY38dtH75H1DOJsgGfWZrcCkTkU3UwPSo86EPCEyA6xGhV1MaccpqqEgjwD3+JO3zciez7MVtbcDx3qZhqIqRhffzcObtICbekl2CFpEabG7tFpkLzxCdlkj0gP4zcpaI30C9jOMsvXRdduGUuTVJMhVX9d1EJs8o64rJR++c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321150; c=relaxed/simple; bh=B1d+cpeaseJ9PKr34K6i49gWQpYLzfuoLU2uD9m2fMs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WPNNi++iUbW0cVameaoftMLXNK3TIHDKv7E3/npJcKCOrE7pCDNfvvcjUUvYYpF5HjZjvMMDZ9pmIYk3tRqbSRRHo/CxElyHSkrhT+bYTtEqBFdA6dxFEjV3dpLm0ZRcMqLerun/beQRj5L57gk8Q1C1cu4ihLN8hVXgP8sKvU8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b6Q/VYCg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="b6Q/VYCg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D630AC433F1; Sun, 24 Mar 2024 22:59:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711321150; bh=B1d+cpeaseJ9PKr34K6i49gWQpYLzfuoLU2uD9m2fMs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b6Q/VYCgOjssQ66ZtsX1vuMUFJ8mKgunAjf5u6IhTFj5BcAzF3GFZyBWb6EYOglXY 2tZ9gZFvwaaFoJsJurHgzT5xdKMt1luCrK1U5jSxBWZhTIl+AP9uVGUdd54d2UMGyQ KAnlbSd+HQWNsVPXZllbR45muFLG9B4nFnyv835kTGusFguBQCW6AwNWNBCM7i/m1J iZ4ko17LLmYi3MD96QnNX+MVGFu7qzZgY5zDqHYxo/qkGQmfCS7pZO5VolaCLvTHCT 8DTnmtz2CpBWdKA6kIgZuxu3KSg2SukKys5v5uKYf6cOsva4biHBPYt7N82Tvrjig2 FhGFYNdgIkPMA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ard Biesheuvel , Sasha Levin Subject: [PATCH 6.7 712/713] x86/efistub: Don't clear BSS twice in mixed mode Date: Sun, 24 Mar 2024 18:47:18 -0400 Message-ID: <20240324224720.1345309-713-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324224720.1345309-1-sashal@kernel.org> References: <20240324224720.1345309-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Ard Biesheuvel [ Upstream commit df7ecce842b846a04d087ba85fdb79a90e26a1b0 ] Clearing BSS should only be done once, at the very beginning. efi_pe_entry() is the entrypoint from the firmware, which may not clear BSS and so it is done explicitly. However, efi_pe_entry() is also used as an entrypoint by the mixed mode startup code, in which case BSS will already have been cleared, and doing it again at this point will corrupt global variables holding the firmware's GDT/IDT and segment selectors. So make the memset() conditional on whether the EFI stub is running in native mode. Fixes: b3810c5a2cc4a666 ("x86/efistub: Clear decompressor BSS in native EFI entrypoint") Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin --- drivers/firmware/efi/libstub/x86-stub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 681f576ec02a0..c9857ee3880c2 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -467,7 +467,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, efi_status_t status; char *cmdline_ptr; - memset(_bss, 0, _ebss - _bss); + if (efi_is_native()) + memset(_bss, 0, _ebss - _bss); efi_system_table = sys_table_arg; -- 2.43.0