linux-kernel - [PATCH v4 10/10] x86/microcode/AMD: Be more tolerant of late parse failures in late loader

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 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:   Fri, 16 Mar 2018 00:08:30 +0100
From:   "Maciej S. Szmigiero" <mail@...iej.szmigiero.name>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v4 10/10] x86/microcode/AMD: Be more tolerant of late parse
 failures in late loader

The early loader just ends its microcode container file processing when it
is unable to parse some patch section, but keeps the already read patches
from this file for their eventual application.

We can do the same in the late loader - we'll just return an error if we
are unable to parse any patches.
Note that we already do silently skip patches in the late loader for
smaller issues like lack of an equivalence table entry, family-size
mismatch or an unsupported chipset match type.

Signed-off-by: Maciej S. Szmigiero <mail@...iej.szmigiero.name>
---
 arch/x86/kernel/cpu/microcode/amd.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 6e25a63a0a3d..f9278d9a2f9b 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -738,13 +738,15 @@ static enum ucode_state __load_microcode_amd(u8 family, const u8 *data,
 	while (leftover) {
 		crnt_size = verify_and_add_patch(family, fw, leftover);
 		if (crnt_size < 0)
-			return ret;
+			break;
 
 		fw	 += crnt_size;
 		leftover -= crnt_size;
+
+		ret = UCODE_OK;
 	}
 
-	return UCODE_OK;
+	return ret;
 }
 
 static enum ucode_state