From: Duoming Zhou duoming@zju.edu.cn
[ Upstream commit 7938e9ce39d6779d2f85d822cc930f73420e54a6 ]
The kmalloc() in zynq_clk_setup() will return null if the physical memory has run out. As a result, if we use snprintf() to write data to the null address, the null pointer dereference bug will happen.
This patch uses a stack variable to replace the kmalloc().
Fixes: 0ee52b157b8e ("clk: zynq: Add clock controller driver") Suggested-by: Michal Simek michal.simek@amd.com Suggested-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Duoming Zhou duoming@zju.edu.cn Link: https://lore.kernel.org/r/20240301084437.16084-1-duoming@zju.edu.cn Acked-by: Michal Simek michal.simek@amd.com Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/zynq/clkc.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/clk/zynq/clkc.c b/drivers/clk/zynq/clkc.c index 204b83d911b90..c615664505a55 100644 --- a/drivers/clk/zynq/clkc.c +++ b/drivers/clk/zynq/clkc.c @@ -42,6 +42,7 @@ static void __iomem *zynq_clkc_base; #define SLCR_SWDT_CLK_SEL (zynq_clkc_base + 0x204)
#define NUM_MIO_PINS 54 +#define CLK_NAME_LEN 16
#define DBG_CLK_CTRL_CLKACT_TRC BIT(0) #define DBG_CLK_CTRL_CPU_1XCLKACT BIT(1) @@ -215,7 +216,7 @@ static void __init zynq_clk_setup(struct device_node *np) int i; u32 tmp; int ret; - char *clk_name; + char clk_name[CLK_NAME_LEN]; unsigned int fclk_enable = 0; const char *clk_output_name[clk_max]; const char *cpu_parents[4]; @@ -425,12 +426,10 @@ static void __init zynq_clk_setup(struct device_node *np) "gem1_emio_mux", CLK_SET_RATE_PARENT, SLCR_GEM1_CLK_CTRL, 0, 0, &gem1clk_lock);
- tmp = strlen("mio_clk_00x"); - clk_name = kmalloc(tmp, GFP_KERNEL); for (i = 0; i < NUM_MIO_PINS; i++) { int idx;
- snprintf(clk_name, tmp, "mio_clk_%2.2d", i); + snprintf(clk_name, CLK_NAME_LEN, "mio_clk_%2.2d", i); idx = of_property_match_string(np, "clock-names", clk_name); if (idx >= 0) can_mio_mux_parents[i] = of_clk_get_parent_name(np, @@ -438,7 +437,6 @@ static void __init zynq_clk_setup(struct device_node *np) else can_mio_mux_parents[i] = dummy_nm; } - kfree(clk_name); clk_register_mux(NULL, "can_mux", periph_parents, 4, CLK_SET_RATE_NO_REPARENT, SLCR_CAN_CLK_CTRL, 4, 2, 0, &canclk_lock);