From 46d4be41b987a6b2d25a2ebdd94cafb44e21d6c5 Mon Sep 17 00:00:00 2001
From: Sam Bobroff <sbobroff@linux.ibm.com>
Date: Fri, 25 May 2018 13:11:30 +1000
Subject: [PATCH] powerpc/eeh: Fix use-after-release of EEH driver
References: bsc#1065729
Patch-mainline: v4.18-rc1
Git-commit: 46d4be41b987a6b2d25a2ebdd94cafb44e21d6c5
Correct two cases where eeh_pcid_get() is used to reference the driver's
module but the reference is dropped before the driver pointer is used.
In eeh_rmv_device() also refactor a little so that only two calls to
eeh_pcid_put() are needed, rather than three and the reference isn't
taken at all if it wasn't needed.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/eeh_driver.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 07e0a42035ce..54333f6c9d67 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -458,9 +458,11 @@ static void *eeh_add_virt_device(void *data, void *userdata)
driver = eeh_pcid_get(dev);
if (driver) {
- eeh_pcid_put(dev);
- if (driver->err_handler)
+ if (driver->err_handler) {
+ eeh_pcid_put(dev);
return NULL;
+ }
+ eeh_pcid_put(dev);
}
#ifdef CONFIG_PCI_IOV
@@ -497,17 +499,19 @@ static void *eeh_rmv_device(void *data, void *userdata)
if (eeh_dev_removed(edev))
return NULL;
- driver = eeh_pcid_get(dev);
- if (driver) {
- eeh_pcid_put(dev);
- if (removed &&
- eeh_pe_passed(edev->pe))
- return NULL;
- if (removed &&
- driver->err_handler &&
- driver->err_handler->error_detected &&
- driver->err_handler->slot_reset)
+ if (removed) {
+ if (eeh_pe_passed(edev->pe))
return NULL;
+ driver = eeh_pcid_get(dev);
+ if (driver) {
+ if (driver->err_handler &&
+ driver->err_handler->error_detected &&
+ driver->err_handler->slot_reset) {
+ eeh_pcid_put(dev);
+ return NULL;
+ }
+ eeh_pcid_put(dev);
+ }
}
/* Remove it from PCI subsystem */
--
2.39.2