diff mbox series

[1/2] clk: Fix clk_core_get NULL dereference

Message ID 20240302-linux-next-24-03-01-simple-clock-fixes-v1-1-25f348a5982b@linaro.org
State New
Headers
Series clk: Fix a core error path and missing qcom camcc-x1e80100 enum |

Commit Message

Bryan O'Donoghue March 2, 2024, 12:52 a.m. UTC 
  It is possible for clk_core_get to dereference a NULL in the following
sequence:

clk_core_get()
    of_clk_get_hw_from_clkspec()
        __of_clk_get_hw_from_provider()
            __clk_get_hw()

__clk_get_hw() can return NULL which is dereferenced by clk_core_get() at
hw->core.

Prior to commit dde4eff47c82 ("clk: Look for parents with clkdev based
clk_lookups") the check IS_ERR_OR_NULL() was performed which would have
caught the NULL.

Reading the description of this function it talks about returning NULL but
that cannot be so at the moment.

Update the function to check for hw before dereferencing it and return NULL
if hw is NULL.

Fixes: dde4eff47c82 ("clk: Look for parents with clkdev based clk_lookups")
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 drivers/clk/clk.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index a3bc7fb90d0f..25371c91a58f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -418,6 +418,9 @@  static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
 	if (IS_ERR(hw))
 		return ERR_CAST(hw);
 
+	if (!hw)
+		return NULL;
+
 	return hw->core;
 }