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authorDuoming Zhou <duoming@zju.edu.cn>2024-03-01 16:44:37 +0800
committerStephen Boyd <sboyd@kernel.org>2024-03-08 17:15:20 -0800
commit7938e9ce39d6779d2f85d822cc930f73420e54a6 (patch)
tree80f7a3ad4acb25ccce65ad8f7810c66e51d011bc /drivers/clk
parentc1ab111e62496d8c1232da767c2bc5cdc76596e5 (diff)
clk: zynq: Prevent null pointer dereference caused by kmalloc failure
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>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/zynq/clkc.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/clk/zynq/clkc.c b/drivers/clk/zynq/clkc.c
index 7bdeaff2bfd6..c28d3dacf0fb 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];
@@ -426,12 +427,10 @@ 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,
@@ -439,7 +438,6 @@ 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);