clk: visconti: prevent array overflow in visconti_clk_register_gates()

This code was using -1 to represent that there was no reset function.
Unfortunately, the -1 was stored in u8 so the if (clks[i].rs_id >= 0)
condition was always true.  This lead to an out of bounds access in
visconti_clk_register_gates().

Fixes: b4cbe606dc36 ("clk: visconti: Add support common clock driver and reset driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220316083533.GA30941@kili
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/visconti/clkc-tmpv770x.c b/drivers/clk/visconti/clkc-tmpv770x.c
index c2b2f41..6c753b2 100644 (file)
--- a/drivers/clk/visconti/clkc-tmpv770x.c
+++ b/drivers/clk/visconti/clkc-tmpv770x.c
@@ -176,7 +176,7 @@ static const struct visconti_clk_gate_table clk_gate_tables[] = {
        { TMPV770X_CLK_WRCK, "wrck",
                clks_parent_data, ARRAY_SIZE(clks_parent_data),
                0, 0x68, 0x168, 9, 32,
-               -1, }, /* No reset */
+               NO_RESET, },
        { TMPV770X_CLK_PICKMON, "pickmon",
                clks_parent_data, ARRAY_SIZE(clks_parent_data),
                0, 0x10, 0x110, 8, 4,

diff --git a/drivers/clk/visconti/clkc.c b/drivers/clk/visconti/clkc.c
index 56a8a4f..d0b193b 100644 (file)
--- a/drivers/clk/visconti/clkc.c
+++ b/drivers/clk/visconti/clkc.c
@@ -147,7 +147,7 @@ int visconti_clk_register_gates(struct visconti_clk_provider *ctx,
                if (!dev_name)
                        return -ENOMEM;
 
-               if (clks[i].rs_id >= 0) {
+               if (clks[i].rs_id != NO_RESET) {
                        rson_offset = reset[clks[i].rs_id].rson_offset;
                        rsoff_offset = reset[clks[i].rs_id].rsoff_offset;
                        rs_idx = reset[clks[i].rs_id].rs_idx;

diff --git a/drivers/clk/visconti/clkc.h b/drivers/clk/visconti/clkc.h
index 09ed82f..8756a1e 100644 (file)
--- a/drivers/clk/visconti/clkc.h
+++ b/drivers/clk/visconti/clkc.h
@@ -73,4 +73,7 @@ int visconti_clk_register_gates(struct visconti_clk_provider *data,
                                 int num_gate,
                                 const struct visconti_reset_data *reset,
                                 spinlock_t *lock);
+
+#define NO_RESET 0xFF
+
 #endif /* _VISCONTI_CLKC_H_ */