From 8fbaa51d43ef2c6a72849ec34060910723a0365f Mon Sep 17 00:00:00 2001 From: Andrew Donnellan Date: Fri, 15 Jul 2016 17:20:36 +1000 Subject: [PATCH] cxl: fix potential NULL dereference in free_adapter() If kzalloc() fails when allocating adapter->guest in cxl_guest_init_adapter(), we call free_adapter() before erroring out. free_adapter() in turn attempts to dereference adapter->guest, which in this case is NULL. In free_adapter(), skip the adapter->guest cleanup if adapter->guest is NULL. Fixes: 14baf4d9c739 ("cxl: Add guest-specific code") Reported-by: Dan Carpenter Signed-off-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/guest.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c index ee7148e78ca7..9aa58a77a24d 100644 --- a/drivers/misc/cxl/guest.c +++ b/drivers/misc/cxl/guest.c @@ -1055,16 +1055,18 @@ static void free_adapter(struct cxl *adapter) struct irq_avail *cur; int i; - if (adapter->guest->irq_avail) { - for (i = 0; i < adapter->guest->irq_nranges; i++) { - cur = &adapter->guest->irq_avail[i]; - kfree(cur->bitmap); + if (adapter->guest) { + if (adapter->guest->irq_avail) { + for (i = 0; i < adapter->guest->irq_nranges; i++) { + cur = &adapter->guest->irq_avail[i]; + kfree(cur->bitmap); + } + kfree(adapter->guest->irq_avail); } - kfree(adapter->guest->irq_avail); + kfree(adapter->guest->status); + kfree(adapter->guest); } - kfree(adapter->guest->status); cxl_remove_adapter_nr(adapter); - kfree(adapter->guest); kfree(adapter); } -- 2.30.2