From: Michal Luczaj <mhal@rbox.co>
To: x86@kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, shuah@kernel.org, luto@kernel.org,
torvalds@linuxfoundation.org, linux-kernel@vger.kernel.org,
Michal Luczaj <mhal@rbox.co>
Subject: [PATCH 1/2] x86/traps: Attempt UMIP fixup only on #GP(0)
Date: Wed, 6 Dec 2023 01:43:44 +0100 [thread overview]
Message-ID: <20231206004654.2986026-2-mhal@rbox.co> (raw)
In-Reply-To: <20231206004654.2986026-1-mhal@rbox.co>
Do not allow for UMIP exception fixup if the exception did not come
directly from the user space. This excludes #GP due to a bad IRET.
Signed-off-by: Michal Luczaj <mhal@rbox.co>
---
arch/x86/kernel/traps.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c876f1d36a81..1daa7cd9a76c 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -651,7 +651,7 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
cond_local_irq_enable(regs);
if (static_cpu_has(X86_FEATURE_UMIP)) {
- if (user_mode(regs) && fixup_umip_exception(regs))
+ if (user_mode(regs) && !error_code && fixup_umip_exception(regs))
goto exit;
}
--
2.43.0
next prev parent reply other threads:[~2023-12-06 1:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-06 0:43 [PATCH 0/2] x86: UMIP emulation leaking kernel addresses Michal Luczaj
2023-12-06 0:43 ` Michal Luczaj [this message]
2023-12-06 0:43 ` [PATCH 2/2] selftests/x86: UMIP DPL=0 segment base address info leak test Michal Luczaj
2023-12-09 15:53 ` [PATCH 0/2] x86: UMIP emulation leaking kernel addresses Borislav Petkov
2023-12-10 17:08 ` Michal Luczaj
2023-12-09 17:16 ` Brian Gerst
2023-12-09 20:08 ` Linus Torvalds
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