[PATCH AUTOSEL 5.7 075/388] clk: zynqmp: fix memory leak in zynqmp_register_clocks

Sasha Levin
2020-06-18T02:49:05Z

From: Quanyang Wang <quanyang.wang@windriver.com>

[ Upstream commit 58b0fb86260063f86afecaebf4056c876fff2a19 ]

This is detected by kmemleak running on zcu102 board:

unreferenced object 0xffffffc877e48180 (size 128):
comm "swapper/0", pid 1, jiffies 4294892909 (age 315.436s)
hex dump (first 32 bytes):
64 70 5f 76 69 64 65 6f 5f 72 65 66 5f 64 69 76 dp_video_ref_div
31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1...............
backtrace:
[<00000000c9be883b>] __kmalloc_track_caller+0x200/0x380
[<00000000f02c3809>] kvasprintf+0x7c/0x100
[<00000000e51dde4d>] kasprintf+0x60/0x80
[<0000000092298b05>] zynqmp_register_clocks+0x29c/0x398
[<00000000faaff182>] zynqmp_clock_probe+0x3cc/0x4c0
[<000000005f5986f0>] platform_drv_probe+0x58/0xa8
[<00000000d5810136>] really_probe+0xd8/0x2a8
[<00000000f5b671be>] driver_probe_device+0x5c/0x100
[<0000000038f91fcf>] __device_attach_driver+0x98/0xb8
[<000000008a3f2ac2>] bus_for_each_drv+0x74/0xd8
[<000000001cb2783d>] __device_attach+0xe0/0x140
[<00000000c268031b>] device_initial_probe+0x24/0x30
[<000000006998de4b>] bus_probe_device+0x9c/0xa8
[<00000000647ae6ff>] device_add+0x3c0/0x610
[<0000000071c14bb8>] of_device_add+0x40/0x50
[<000000004bb5d132>] of_platform_device_create_pdata+0xbc/0x138

This is because that when num_nodes is larger than 1, clk_out is
allocated using kasprintf for these nodes but only the last node's
clk_out is freed.

Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lkml.kernel.org/r/1583185843-20707-5-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/zynqmp/clkc.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/zynqmp/clkc.c b/drivers/clk/zynqmp/clkc.c
index 10e89f23880b..b66c3a62233a 100644
--- a/drivers/clk/zynqmp/clkc.c
+++ b/drivers/clk/zynqmp/clkc.c
@@ -558,7 +558,7 @@ static struct clk_hw *zynqmp_register_clk_topology(int clk_id, char *clk_name,
{
int j;
u32 num_nodes, clk_dev_id;
- char *clk_out = NULL;
+ char *clk_out[MAX_NODES];
struct clock_topology *nodes;
struct clk_hw *hw = NULL;

@@ -572,16 +572,16 @@ static struct clk_hw *zynqmp_register_clk_topology(int clk_id, char *clk_name,
* Intermediate clock names are postfixed with type of clock.
*/
if (j != (num_nodes - 1)) {
- clk_out = kasprintf(GFP_KERNEL, "%s%s", clk_name,
+ clk_out[j] = kasprintf(GFP_KERNEL, "%s%s", clk_name,
clk_type_postfix[nodes[j].type]);
} else {
- clk_out = kasprintf(GFP_KERNEL, "%s", clk_name);
+ clk_out[j] = kasprintf(GFP_KERNEL, "%s", clk_name);
}

if (!clk_topology[nodes[j].type])
continue;

- hw = (*clk_topology[nodes[j].type])(clk_out, clk_dev_id,
+ hw = (*clk_topology[nodes[j].type])(clk_out[j], clk_dev_id,
parent_names,
num_parents,
&nodes[j]);
@@ -590,9 +590,12 @@ static struct clk_hw *zynqmp_register_clk_topology(int clk_id, char *clk_name,
__func__, clk_dev_id, clk_name,
PTR_ERR(hw));

- parent_names[0] = clk_out;
+ parent_names[0] = clk_out[j];
}
- kfree(clk_out);
+
+ for (j = 0; j < num_nodes; j++)
+ kfree(clk_out[j]);
+
return hw;
}

--
2.25.1