[PATCH 3/4] regulator: avoid resolve_supply() infinite recursion

From: Michał Mirosław
Date: Thu Nov 12 2020 - 19:16:57 EST


When a regulator's name equals its supply's name the
regulator_resolve_supply() recurses indefinitely. Add a check
so that debugging the problem is easier. The "fixed" commit
just exposed the problem.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
---
drivers/regulator/core.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index ad36f03d7ee6..ab922ed273f3 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1841,6 +1841,12 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
}
}

+ if (r == rdev) {
+ dev_err(dev, "Supply for %s (%s) resolved to itself\n",
+ rdev->desc->name, rdev->supply_name);
+ return -EINVAL;
+ }
+
/*
* If the supply's parent device is not the same as the
* regulator's parent device, then ensure the parent device
--
2.20.1