clk: vc5: Fix use after free in vc5_probe
Subsystems (2)
PATCH 1/1 clk: vc5: Fix use after free in vc5_probe
From: Tom Rix <[email protected]>
clang static analysis reports this error
clk-versaclock5.c:887:3: warning: Use of memory after it is freed
[unix.Malloc]
dev_err(&client->dev, "unable to register %s\n", init.name);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A representative problem block of code is
ret = devm_clk_hw_register(&client->dev, &vc5->clk_mux);
kfree(init.name); /* clock framework made a copy of the name */
if (ret) {
dev_err(&client->dev, "unable to register %s\n", init.name);
goto err_clk;
}init.name is freed and then used.
So reorder the free.
--- drivers/clk/clk-versaclock5.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)
drivers/clk/clk-versaclock5.c +14 -7
@@ -882,11 +882,12 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) init.parent_names = parent_names; vc5->clk_mux.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_mux); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ if (vc5->chip_info->flags &VC5_HAS_PFD_FREQ_DBL ) {/* Register frequency doubler */
@@ -900,12 +901,13 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) init.num_parents =1 ; vc5->clk_mul.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_mul); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ }/* Register PFD */
@@ -921,11 +923,12 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) init.num_parents =1 ; vc5->clk_pfd.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_pfd); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ /* Register PLL */ memset (&init,0 ,sizeof (init));
@@ -939,11 +942,12 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) vc5->clk_pll.vc5 = vc5; vc5->clk_pll.hw.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_pll.hw); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ /* Register FODs */ for (n =0 ; n < vc5->chip_info->clk_fod_cnt; n++) {
@@ -960,12 +964,13 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) vc5->clk_fod[n].vc5 = vc5; vc5->clk_fod[n].hw.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_fod[n].hw); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ }/* Register MUX-connected OUT0_I2C_SELB output */
@@ -981,11 +986,12 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) vc5->clk_out[0 ].vc5 = vc5; vc5->clk_out[0 ].hw.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_out[0 ].hw); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ /* Register FOD-connected OUTx outputs */ for (n =1 ; n < vc5->chip_info->clk_out_cnt; n++) {
@@ -1008,12 +1014,13 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id) vc5->clk_out[n].vc5 = vc5; vc5->clk_out[n].hw.init = &init; ret =devm_clk_hw_register (&client->dev, &vc5->clk_out[n].hw); -kfree (init.name);/* clock framework made a copy of the name */ if (ret) {dev_err (&client->dev,"unable to register %s\n" , init.name); +kfree (init.name); goto err_clk; } +kfree (init.name);/* clock framework made a copy of the name */ /* Fetch Clock Output configuration from DT (if specified) */ ret =vc5_get_output_config (client, &vc5->clk_out[n]);
Signature · 1 line
2.18.1
Stephen Boyd
maintainerQuoting [email protected] (2020-07-19 07:33:24)
Quoted 18 lines
From: Tom Rix <[email protected]>
clang static analysis reports this error
clk-versaclock5.c:887:3: warning: Use of memory after it is freed
[unix.Malloc]dev_err(&client->dev, "unable to register %s\n", init.name); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A representative problem block of code is
ret =
devm_clk_hw_register(&client->dev, &vc5->clk_mux);
kfree(init.name); /* clock framework made a copy of the name */if (ret) { dev_err(&client->dev, "unable to register %s\n", init.name); goto err_clk; }
Quoted 8 lines
init.name is freed and then used.
So reorder the free.
Fixes f491276a5168 ("clk: vc5: Allow Versaclock driver to support multiple instances")Signed-off-by Tom Rix <[email protected]>---
There's another patch on the mailing list for this.