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 166F912D75C; Sun, 24 Mar 2024 23:11:48 +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=1711321909; cv=none; b=TVnO6Ag67PGAsbKFJVgQo1s1Uek9i302D4xWsietvG38leMfsK/t55sdBE1FQ+et2G1qkvkdOkidLWcYG1L2rOj5RbhmbuCh5EBE1wrPvJFJywpIRPiUJoX1yawdySExfnNsCbVm1pglBP4lVn8Akh5nrsurk1PWLzsBzp/Hy1M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321909; c=relaxed/simple; bh=S4MCq1btvMlsLJir7xY09Oy+WFy5jVRxyUJY7arKk9U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TxgQoONK4ykuvmeoQJfJeSNhDLeKBvKskRqiiIMLozsoGYDoCu4vrh3G4wwsbs1ggkDt+w9emvBuuIWm4PhGPRa3lekmSUK6lhj5fqVAU5grZfNHoC1Fu29EZYyjkbpTg0LQShCTCpHyySJuCiGO4bTlGPz4b3FQpT5RflZRpPo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j9WjlUS0; 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="j9WjlUS0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A3F7C433F1; Sun, 24 Mar 2024 23:11:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711321908; bh=S4MCq1btvMlsLJir7xY09Oy+WFy5jVRxyUJY7arKk9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j9WjlUS0WLf6CwwtFb1nOx4Om/SQ3h8wpqBvcR1C6cBQ+lxZWZcz6R4D2ieE2Kx8q JHhPrTn3Jx8z/BOCTUum5/ai3jqJKxQKSYQdMzMzPCwULNtNr3Wp3HjQQvnk6gPcEV AVCr/8tq2I7t6xy63YXZY/8Lv4nBOWgktvclnfTcmUWEK5QS5QIyAdhotyFmowT8P2 0Ij4+wXHnsexBCmL+k0gOpbg+PLazX+s4FqFpuhpYxZB+aMsssdpkkFC/wUYYb/NHX QHYYhxaQidTpEJNNxKRmHE1EX1D/t9/VAd56RkT6KBNMnK2pm8e9mmENGRkWS0q4Rm 5pTcQn7Yyi5ow== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ard Biesheuvel , Sasha Levin Subject: [PATCH 6.6 637/638] x86/efistub: Don't clear BSS twice in mixed mode Date: Sun, 24 Mar 2024 19:01:14 -0400 Message-ID: <20240324230116.1348576-638-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324230116.1348576-1-sashal@kernel.org> References: <20240324230116.1348576-1-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 90f18315e0247..d186617a93f88 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