[PATCH 4.19 223/271] x86/boot: Fix memory leak in default_get_smp_config()

From: Greg Kroah-Hartman
Date: Thu Jul 25 2019 - 11:02:46 EST


From: David Rientjes <rientjes@xxxxxxxxxx>

commit e74bd96989dd42a51a73eddb4a5510a6f5e42ac3 upstream.

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@xxxxxxxxxx>
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907091942570.28240@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kernel/mpparse.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -547,17 +547,15 @@ void __init default_get_smp_config(unsig
* 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(unsig
/*
* Only use the first configuration found.
*/
-
+out:
early_memunmap(mpf, sizeof(*mpf));
}