linux-kernel - [RFC PATCH 25/47] mm: asi: Avoid warning from NMI userspace accesses in ASI context

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

Message-Id: <20220223052223.1202152-26-junaids@google.com>
Date:   Tue, 22 Feb 2022 21:22:01 -0800
From:   Junaid Shahid <junaids@...gle.com>
To:     linux-kernel@...r.kernel.org
Cc:     kvm@...r.kernel.org, pbonzini@...hat.com, jmattson@...gle.com,
        pjt@...gle.com, oweisse@...gle.com, alexandre.chartre@...cle.com,
        rppt@...ux.ibm.com, dave.hansen@...ux.intel.com,
        peterz@...radead.org, tglx@...utronix.de, luto@...nel.org,
        linux-mm@...ck.org
Subject: [RFC PATCH 25/47] mm: asi: Avoid warning from NMI userspace accesses
 in ASI context

nmi_uaccess_okay() emits a warning if current CR3 != mm->pgd.
Limit the warning to only when ASI is not active.

Signed-off-by: Junaid Shahid <junaids@...gle.com>


---
 arch/x86/mm/tlb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 25bee959d1d3..628f1cd904ac 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -1292,7 +1292,8 @@ bool nmi_uaccess_okay(void)
 	if (loaded_mm != current_mm)
 		return false;
 
-	VM_WARN_ON_ONCE(current_mm->pgd != __va(read_cr3_pa()));
+	VM_WARN_ON_ONCE(current_mm->pgd != __va(read_cr3_pa()) &&
+			!is_asi_active());
 
 	return true;
 }
-- 
2.35.1.473.g83b2b277ed-goog