From 827b17c468b0dae69f82f852958d16f4bf6d6bf0 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Wed, 4 Oct 2017 11:02:31 +0200 Subject: [PATCH] spapr: sanity check size of the CAS buffer The CAS buffer is provided by SLOF. A broken SLOF could pass a silly size: either smaller than the diff header, in which case the current code will try to allocate 16 Exabytes of memory and g_malloc0() will abort, or bigger than the maximum memory provisioned for SLOF (ie, 40 Megabytes), which doesn't make sense. Both cases indicate that SLOF has a bug. Let's print out an explicit error message and exit since rebooting as we do with other errors would only result in a reset loop. Signed-off-by: Greg Kurz [dwg: Fix format specifier that broke 32-bit builds] Signed-off-by: David Gibson --- hw/ppc/spapr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index b284e0b9d4..079e493ef4 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -819,6 +819,13 @@ int spapr_h_cas_compose_response(sPAPRMachineState *spapr, return 1; } + if (size < sizeof(hdr) || size > FW_MAX_SIZE) { + error_report("SLOF provided an unexpected CAS buffer size " + TARGET_FMT_lu " (min: %zu, max: %u)", + size, sizeof(hdr), FW_MAX_SIZE); + exit(EXIT_FAILURE); + } + size -= sizeof(hdr); /* Create skeleton */