clk: stm32: Fix out-by-one error path in the index lookup

If stm32f4_rcc_lookup() is called with primary == 0 and secondary == 192 then it will read beyond the end of the table array due to an out-by-one error in the range check. In addition to the fixing the inequality we also modify the r.h.s. to make it even more explicit that we are comparing against the size of table in bits. Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Daniel Thompson <[email protected]> Acked-by: Maxime Coquelin <[email protected]> Fixes: 358bdf8 ("clk: stm32: Add clock driver for STM32F4[23]xxx devices") Signed-off-by: Stephen Boyd <[email protected]>
TechNexion · Jul 2, 2015 · 15ab382 · 15ab382
1 parent 69916d9
commit 15ab382
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
@@ -268,7 +268,7 @@ static int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary)
 	memcpy(table, stm32f42xx_gate_map, sizeof(table));
 
 	/* only bits set in table can be used as indices */
-	if (WARN_ON(secondary > 8 * sizeof(table) ||
+	if (WARN_ON(secondary >= BITS_PER_BYTE * sizeof(table) ||
 		    0 == (table[BIT_ULL_WORD(secondary)] &
 			  BIT_ULL_MASK(secondary))))
 		return -EINVAL;