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

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

[David Rientjes]

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));
 }
 

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

[tip-bot for David Rientjes]

Commit-ID:  e74bd96989dd42a51a73eddb4a5510a6f5e42ac3
Gitweb:     https://git.kernel.org/tip/e74bd96989dd42a51a73eddb4a5510a6f5e42ac3
Author:     David Rientjes <rientjes@google.com>
AuthorDate: Tue, 9 Jul 2019 19:44:03 -0700
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 16 Jul 2019 23:13:48 +0200

x86/boot: Fix memory leak in default_get_smp_config()

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>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907091942570.28240@chino.kir.corp.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 1bfe5c6e6cfe..afac7ccce72f 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -546,17 +546,15 @@ 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();
 
@@ -565,7 +563,7 @@ void __init default_get_smp_config(unsigned int early)
 	/*
 	 * Only use the first configuration found.
 	 */
-
+out:
 	early_memunmap(mpf, sizeof(*mpf));
 }