[PATCH 5.5 322/399] driver core: platform: fix u32 greater or equal to zero comparison

Greg Kroah-Hartman
2020-02-21T08:40:23Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit 0707cfa5c3ef58effb143db9db6d6e20503f9dec ]

Currently the check that a u32 variable i is >= 0 is always true because
the unsigned variable will never be negative, causing the loop to run
forever. Fix this by changing the pre-decrement check to a zero check on
i followed by a decrement of i.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 39cc539f90d0 ("driver core: platform: Prevent resouce overflow from causing infinite loops")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200116175758.88396-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/platform.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 864b53b3d5980..7fa654f1288b8 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -571,7 +571,7 @@ int platform_device_add(struct platform_device *pdev)
pdev->id = PLATFORM_DEVID_AUTO;
}

- while (--i >= 0) {
+ while (i--) {
struct resource *r = &pdev->resource[i];
if (r->parent)
release_resource(r);
--
2.20.1