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| author | Dmitry Osipenko <digetx@gmail.com> | 2020-08-31 23:43:35 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-09-01 15:26:28 +0300 |
| commit | 0a7416f94707c60b9f66b01c0a505b7e41375f3a (patch) | |
| tree | 6df5115827f260e3ee84a4d8e218df2435743361 /drivers/regulator | |
| parent | 3bec5b6aae830355e786e204b20a7cea38c3a8ed (diff) | |
| download | linux-0a7416f94707c60b9f66b01c0a505b7e41375f3a.tar.xz | |
regulator: core: Fix slab-out-of-bounds in regulator_unlock_recursive()
The recent commit 7d8196641ee1 ("regulator: Remove pointer table
overallocation") changed the size of coupled_rdevs and now KASAN is able
to detect slab-out-of-bounds problem in regulator_unlock_recursive(),
which is a legit problem caused by a typo in the code. The recursive
unlock function uses n_coupled value of a parent regulator for unlocking
supply regulator, while supply's n_coupled should be used. In practice
problem may only affect platforms that use coupled regulators.
Cc: stable@vger.kernel.org # 5.0+
Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200831204335.19489-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/regulator')
| -rw-r--r-- | drivers/regulator/core.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 6789d1efdf5d..0e764596b0c0 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -236,8 +236,8 @@ static bool regulator_supply_is_couple(struct regulator_dev *rdev) static void regulator_unlock_recursive(struct regulator_dev *rdev, unsigned int n_coupled) { - struct regulator_dev *c_rdev; - int i; + struct regulator_dev *c_rdev, *supply_rdev; + int i, supply_n_coupled; for (i = n_coupled; i > 0; i--) { c_rdev = rdev->coupling_desc.coupled_rdevs[i - 1]; @@ -245,10 +245,13 @@ static void regulator_unlock_recursive(struct regulator_dev *rdev, if (!c_rdev) continue; - if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) - regulator_unlock_recursive( - c_rdev->supply->rdev, - c_rdev->coupling_desc.n_coupled); + if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) { + supply_rdev = c_rdev->supply->rdev; + supply_n_coupled = supply_rdev->coupling_desc.n_coupled; + + regulator_unlock_recursive(supply_rdev, + supply_n_coupled); + } regulator_unlock(c_rdev); } |