This is a note to let you know that I've just added the patch titled
x86/mm: Fix use of uninitialized buffer in sme_enable()
to the 6.2-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:
x86-mm-fix-use-of-uninitialized-buffer-in-sme_enable.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cbebd68f59f03633469f3ecf9bea99cd6cce3854 Mon Sep 17 00:00:00 2001
From: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
Date: Mon, 6 Mar 2023 08:06:56 -0800
Subject: x86/mm: Fix use of uninitialized buffer in sme_enable()
From: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
commit cbebd68f59f03633469f3ecf9bea99cd6cce3854 upstream.
cmdline_find_option() may fail before doing any initialization of
the buffer array. This may lead to unpredictable results when the same
buffer is used later in calls to strncmp() function. Fix the issue by
returning early if cmdline_find_option() returns an error.
Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.
Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: <stable@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230306160656.14844-1-n.zhandarovich@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/mem_encrypt_identity.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -600,7 +600,8 @@ void __init sme_enable(struct boot_param
cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
((u64)bp->ext_cmd_line_ptr << 32));
- cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+ if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0)
+ return;
if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
sme_me_mask = me_mask;
Patches currently in stable-queue which might be from n.zhandarovich@xxxxxxxxxx are
queue-6.2/x86-mm-fix-use-of-uninitialized-buffer-in-sme_enable.patch
