[patch] x86/boot: Fix memory leak in default_get_smp_config()

From: David Rientjes <rientjes@google.com>
To: Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
	linux-kernel@vger.kernel.org, x86@kernel.org
Subject: [patch] x86/boot: Fix memory leak in default_get_smp_config()
Date: Tue, 9 Jul 2019 19:44:03 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.21.1907091942570.28240@chino.kir.corp.google.com> (raw)

When default_get_smp_config() is called with early == 1 and mpf->feature1
is non-zero, mpf is leaked because the return path does not do
early_memunmap().

Fix this and share a common exit routine.

Fixes: 5997efb96756 ("x86/boot: Use memremap() to map the MPF and MPC
data")
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
---
 arch/x86/kernel/mpparse.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index f1c5eb99d445..7a7055056b0d 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -547,17 +547,15 @@ void __init default_get_smp_config(unsigned int early)
 			 * local APIC has default address
 			 */
 			mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
-			return;
+			goto out;
 		}
 
 		pr_info("Default MP configuration #%d\n", mpf->feature1);
 		construct_default_ISA_mptable(mpf->feature1);
 
 	} else if (mpf->physptr) {
-		if (check_physptr(mpf, early)) {
-			early_memunmap(mpf, sizeof(*mpf));
-			return;
-		}
+		if (check_physptr(mpf, early))
+			goto out;
 	} else
 		BUG();
 
@@ -566,7 +564,7 @@ void __init default_get_smp_config(unsigned int early)
 	/*
 	 * Only use the first configuration found.
 	 */
-
+out:
 	early_memunmap(mpf, sizeof(*mpf));
 }
 
