[PATCH] clk: samsung: Fix UBSAN panic in samsung_clk_init()

From: Will McVicker
Date: Wed Feb 12 2025 - 13:33:14 EST


With UBSAN_ARRAY_BOUNDS=y, I'm hitting the below panic due to
dereferencing `ctx->clk_data.hws` before setting
`ctx->clk_data.num = nr_clks`. Move that up to fix the crash.

UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP
<snip>
Call trace:
samsung_clk_init+0x110/0x124 (P)
samsung_clk_init+0x48/0x124 (L)
samsung_cmu_register_one+0x3c/0xa0
exynos_arm64_register_cmu+0x54/0x64
__gs101_cmu_top_of_clk_init_declare+0x28/0x60
...

Fixes: e620a1e061c4 ("drivers/clk: convert VL struct to struct_size")
Signed-off-by: Will McVicker <willmcvicker@xxxxxxxxxx>
---
drivers/clk/samsung/clk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk.c b/drivers/clk/samsung/clk.c
index 283c523763e6..8d440cf56bd4 100644
--- a/drivers/clk/samsung/clk.c
+++ b/drivers/clk/samsung/clk.c
@@ -74,12 +74,12 @@ struct samsung_clk_provider * __init samsung_clk_init(struct device *dev,
if (!ctx)
panic("could not allocate clock provider context.\n");

+ ctx->clk_data.num = nr_clks;
for (i = 0; i < nr_clks; ++i)
ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);

ctx->dev = dev;
ctx->reg_base = base;
- ctx->clk_data.num = nr_clks;
spin_lock_init(&ctx->lock);

return ctx;

base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
--
2.48.1.502.g6dc24dfdaf-goog