* [PATCH] clk: vc5: Fix use after free in vc5_probe
@ 2020-07-19 14:33 trix
2020-07-21 9:17 ` Stephen Boyd
0 siblings, 1 reply; 2+ messages in thread
From: trix @ 2020-07-19 14:33 UTC (permalink / raw)
To: marek.vasut, mturquette, sboyd, aford173; +Cc: linux-clk, linux-kernel, Tom Rix
From: Tom Rix <trix@redhat.com>
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.
Fixes: f491276a5168 ("clk: vc5: Allow Versaclock driver to support multiple instances")
Signed-off-by: Tom Rix <trix@redhat.com>
---
drivers/clk/clk-versaclock5.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
index 9a5fb3834b9a..72c9ae460a01 100644
--- a/drivers/clk/clk-versaclock5.c
+++ b/drivers/clk/clk-versaclock5.c
@@ -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]);
--
2.18.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] clk: vc5: Fix use after free in vc5_probe
2020-07-19 14:33 [PATCH] clk: vc5: Fix use after free in vc5_probe trix
@ 2020-07-21 9:17 ` Stephen Boyd
0 siblings, 0 replies; 2+ messages in thread
From: Stephen Boyd @ 2020-07-21 9:17 UTC (permalink / raw)
To: aford173, marek.vasut, mturquette, trix; +Cc: linux-clk, linux-kernel, Tom Rix
Quoting trix@redhat.com (2020-07-19 07:33:24)
> From: Tom Rix <trix@redhat.com>
>
> 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.
>
> Fixes: f491276a5168 ("clk: vc5: Allow Versaclock driver to support multiple instances")
>
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
There's another patch on the mailing list for this.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-07-19 14:33 [PATCH] clk: vc5: Fix use after free in vc5_probe trix
2020-07-21 9:17 ` Stephen Boyd
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