diff options
| author | Lee Jones <lee.jones@linaro.org> | 2019-10-21 10:16:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-01 13:14:26 +0200 |
| commit | 66bde9c7f036cf7e6c36ec16f90f354df3e779ab (patch) | |
| tree | 2c375ce2cdc25f3c966ed03dc64eee7de7fd79c3 | |
| parent | 6edb956e3c9d7b6936a236b1647b1a1ea993ea5d (diff) | |
mfd: mfd-core: Protect against NULL call-back function pointer
[ Upstream commit b195e101580db390f50b0d587b7f66f241d2bc88 ]
If a child device calls mfd_cell_{en,dis}able() without an appropriate
call-back being set, we are likely to encounter a panic. Avoid this
by adding suitable checking.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/mfd/mfd-core.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 182973df1aed..77c965c6a65f 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -32,6 +32,11 @@ int mfd_cell_enable(struct platform_device *pdev) const struct mfd_cell *cell = mfd_get_cell(pdev); int err = 0; + if (!cell->enable) { + dev_dbg(&pdev->dev, "No .enable() call-back registered\n"); + return 0; + } + /* only call enable hook if the cell wasn't previously enabled */ if (atomic_inc_return(cell->usage_count) == 1) err = cell->enable(pdev); @@ -49,6 +54,11 @@ int mfd_cell_disable(struct platform_device *pdev) const struct mfd_cell *cell = mfd_get_cell(pdev); int err = 0; + if (!cell->disable) { + dev_dbg(&pdev->dev, "No .disable() call-back registered\n"); + return 0; + } + /* only disable if no other clients are using it */ if (atomic_dec_return(cell->usage_count) == 0) err = cell->disable(pdev); |