lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 29 May 2019 20:04:47 -0700
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Takashi Iwai <tiwai@...e.de>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        Peter Jones <pjones@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-efi@...r.kernel.org, Ingo Molnar <mingo@...nel.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.1 289/405] efifb: Omit memory map check on legacy boot

[ Upstream commit c2999c281ea2d2ebbdfce96cecc7b52e2ae7c406 ]

Since the following commit:

  38ac0287b7f4 ("fbdev/efifb: Honour UEFI memory map attributes when mapping the FB")

efifb_probe() checks its memory range via efi_mem_desc_lookup(),
and this leads to a spurious error message:

   EFI_MEMMAP is not enabled

at every boot on KVM.  This is quite annoying since the error message
appears even if you set "quiet" boot option.

Since this happens on legacy boot, which strangely enough exposes
a EFI framebuffer via screen_info, let's double check that we are
doing an EFI boot before attempting to access the EFI memory map.

Reported-by: Takashi Iwai <tiwai@...e.de>
Tested-by: Takashi Iwai <tiwai@...e.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Matt Fleming <matt@...eblueprint.co.uk>
Cc: Peter Jones <pjones@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: linux-efi@...r.kernel.org
Link: http://lkml.kernel.org/r/20190328193429.21373-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/video/fbdev/efifb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index fd02e8a4841d6..9f39f0c360e0c 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -464,7 +464,8 @@ static int efifb_probe(struct platform_device *dev)
 	info->apertures->ranges[0].base = efifb_fix.smem_start;
 	info->apertures->ranges[0].size = size_remap;
 
-	if (!efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
+	if (efi_enabled(EFI_BOOT) &&
+	    !efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
 		if ((efifb_fix.smem_start + efifb_fix.smem_len) >
 		    (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
 			pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
-- 
2.20.1



Powered by blists - more mailing lists