From: André Draszik Date: Fri, 9 Jan 2026 08:38:38 +0000 (+0000) Subject: regulator: core: fix locking in regulator_resolve_supply() error path X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=497330b203d2c59c5ff3fa4c34d14494d7203bc3;p=thirdparty%2Fkernel%2Flinux.git regulator: core: fix locking in regulator_resolve_supply() error path If late enabling of a supply regulator fails in regulator_resolve_supply(), the code currently triggers a lockdep warning: WARNING: drivers/regulator/core.c:2649 at _regulator_put+0x80/0xa0, CPU#6: kworker/u32:4/596 ... Call trace: _regulator_put+0x80/0xa0 (P) regulator_resolve_supply+0x7cc/0xbe0 regulator_register_resolve_supply+0x28/0xb8 as the regulator_list_mutex must be held when calling _regulator_put(). To solve this, simply switch to using regulator_put(). While at it, we should also make sure that no concurrent access happens to our rdev while we clear out the supply pointer. Add appropriate locking to ensure that. While the code in question will be removed altogether in a follow-up commit, I believe it is still beneficial to have this corrected before removal for future reference. Fixes: 36a1f1b6ddc6 ("regulator: core: Fix memory leak in regulator_resolve_supply()") Fixes: 8e5356a73604 ("regulator: core: Clear the supply pointer if enabling fails") Signed-off-by: André Draszik Link: https://patch.msgid.link/20260109-regulators-defer-v2-2-1a25dc968e60@linaro.org Signed-off-by: Mark Brown --- diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index a723bd00e1716..48c091de68d81 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2285,8 +2285,16 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) if (rdev->use_count) { ret = regulator_enable(rdev->supply); if (ret < 0) { - _regulator_put(rdev->supply); + struct regulator *supply; + + regulator_lock_two(rdev, rdev->supply->rdev, &ww_ctx); + + supply = rdev->supply; rdev->supply = NULL; + + regulator_unlock_two(rdev, supply->rdev, &ww_ctx); + + regulator_put(supply); goto out; } }