[PATCH v2 1/3] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error

[PATCH v2 1/3] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error

[Christophe JAILLET]

If clk_get_rate() fails, the clk that has just been allocated needs to be
freed.

Cc: <stable@vger.kernel.org> # v3.3+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
v2: Add an error message    [Andi Shyti]
    Add Cc: stable          [Andi Shyti]
    Add R-b tags

v1: https://lore.kernel.org/all/e4359d5ef206f5b349c1d15a515a1205e78dda55.1686285892.git.christophe.jaillet@wanadoo.fr/

Slightly unsure if Krzysztof's R-b should be kept or not.
v2 is not the same as v1, but the change looks small.
Sorry if I did wrong.
---
 drivers/tty/serial/samsung_tty.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 2a7520ad3abd..a92a23e1964e 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1459,8 +1459,12 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			continue;
 
 		rate = clk_get_rate(clk);
-		if (!rate)
+		if (!rate) {
+			dev_err(ourport->port.dev,
+				"Failed to get clock rate for %s.\n", clkname);
+			clk_put(clk);
 			continue;
+		}
 
 		if (ourport->info->has_divslot) {
 			unsigned long div = rate / req_baud;
-- 
2.34.1

[PATCH v2 2/3] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk

[Christophe JAILLET]

When the best clk is searched, we iterate over all possible clk.

If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.

Cc: <stable@vger.kernel.org> # v3.3+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
I think that some clk_put() are also missing somewhere else in the driver
but won't be able to investigate further.

v2: No code change
    Add Cc: stable          [Andi Shyti, as suggested for patch 1/2]
    Add R-b tags

v1: https://lore.kernel.org/all/93bf8f574310256fcea50e5c5a62b5c37e20bb14.1686285892.git.christophe.jaillet@wanadoo.fr/
---
 drivers/tty/serial/samsung_tty.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index a92a23e1964e..0b37019820b4 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1490,10 +1490,18 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			calc_deviation = -calc_deviation;
 
 		if (calc_deviation < deviation) {
+			/*
+			 * If we find a better clk, release the previous one, if
+			 * any.
+			 */
+			if (!IS_ERR(*best_clk))
+				clk_put(*best_clk);
 			*best_clk = clk;
 			best_quot = quot;
 			*clk_num = cnt;
 			deviation = calc_deviation;
+		} else {
+			clk_put(clk);
 		}
 	}
 
-- 
2.34.1

[PATCH v2 3/3] tty: serial: samsung_tty: Use abs() to simplify some code

[Christophe JAILLET]

Use abs() instead of hand-writing it.

Suggested-by: Walter Harms <wharms@bfs.de>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
v2: new patch
---
 drivers/tty/serial/samsung_tty.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 0b37019820b4..b29e9dfd81a6 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -24,6 +24,7 @@
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
+#include <linux/math.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
@@ -1485,9 +1486,7 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 		}
 		quot--;
 
-		calc_deviation = req_baud - baud;
-		if (calc_deviation < 0)
-			calc_deviation = -calc_deviation;
+		calc_deviation = abs(req_baud - baud);
 
 		if (calc_deviation < deviation) {
 			/*
-- 
2.34.1

Re: [PATCH v2 3/3] tty: serial: samsung_tty: Use abs() to simplify some code

[Andi Shyti]

Hi Christophe,

On Sat, Jun 10, 2023 at 05:59:27PM +0200, Christophe JAILLET wrote:
> Use abs() instead of hand-writing it.
> 
> Suggested-by: Walter Harms <wharms@bfs.de>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Andi Shyti <andi.shyti@kernel.org> 

Andi

Re: [PATCH v2 3/3] tty: serial: samsung_tty: Use abs() to simplify some code

[Jiri Slaby]

On 10. 06. 23, 17:59, Christophe JAILLET wrote:
> Use abs() instead of hand-writing it.
> 
> Suggested-by: Walter Harms <wharms@bfs.de>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> v2: new patch
> ---
>   drivers/tty/serial/samsung_tty.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index 0b37019820b4..b29e9dfd81a6 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -24,6 +24,7 @@
>   #include <linux/dmaengine.h>
>   #include <linux/dma-mapping.h>
>   #include <linux/slab.h>
> +#include <linux/math.h>
>   #include <linux/module.h>
>   #include <linux/ioport.h>
>   #include <linux/io.h>
> @@ -1485,9 +1486,7 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
>   		}
>   		quot--;
>   
> -		calc_deviation = req_baud - baud;
> -		if (calc_deviation < 0)
> -			calc_deviation = -calc_deviation;
> +		calc_deviation = abs(req_baud - baud);

Does this work provided req_baud and baud are unsigned?

thanks,
-- 
js
suse labs

Re: [PATCH v2 2/3] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk

[Jiri Slaby]

On 10. 06. 23, 17:59, Christophe JAILLET wrote:
> When the best clk is searched, we iterate over all possible clk.
> 
> If we find a better match, the previous one, if any, needs to be freed.
> If a better match has already been found, we still need to free the new
> one, otherwise it leaks.
> 
> Cc: <stable@vger.kernel.org> # v3.3+
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
> Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

thanks,
-- 
js
suse labs

Re: [PATCH v2 1/3] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error

[Jiri Slaby]

On 10. 06. 23, 17:59, Christophe JAILLET wrote:
> If clk_get_rate() fails, the clk that has just been allocated needs to be
> freed.
> 
> Cc: <stable@vger.kernel.org> # v3.3+
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
> Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

thanks,
-- 
js
suse labs

Re: [PATCH v2 3/3] tty: serial: samsung_tty: Use abs() to simplify some code

[Jiri Slaby]

On 12. 06. 23, 7:13, Jiri Slaby wrote:
> On 10. 06. 23, 17:59, Christophe JAILLET wrote:
>> Use abs() instead of hand-writing it.
>>
>> Suggested-by: Walter Harms <wharms@bfs.de>
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>> v2: new patch
>> ---
>>   drivers/tty/serial/samsung_tty.c | 5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/tty/serial/samsung_tty.c 
>> b/drivers/tty/serial/samsung_tty.c
>> index 0b37019820b4..b29e9dfd81a6 100644
>> --- a/drivers/tty/serial/samsung_tty.c
>> +++ b/drivers/tty/serial/samsung_tty.c
>> @@ -24,6 +24,7 @@
>>   #include <linux/dmaengine.h>
>>   #include <linux/dma-mapping.h>
>>   #include <linux/slab.h>
>> +#include <linux/math.h>
>>   #include <linux/module.h>
>>   #include <linux/ioport.h>
>>   #include <linux/io.h>
>> @@ -1485,9 +1486,7 @@ static unsigned int s3c24xx_serial_getclk(struct 
>> s3c24xx_uart_port *ourport,
>>           }
>>           quot--;
>> -        calc_deviation = req_baud - baud;
>> -        if (calc_deviation < 0)
>> -            calc_deviation = -calc_deviation;
>> +        calc_deviation = abs(req_baud - baud);
> 
> Does this work provided req_baud and baud are unsigned?

Oh, yes, it does, _hopefully_. A bit unexpectedly for me, but:
  * abs - return absolute value of an argument
  * @x: the value.  If it is unsigned type, it is converted to signed 
type first.

So:

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

It would help noting this in the commit log.

> thanks,-- 
js
suse labs

patch "tty: serial: samsung_tty: Fix a memory leak in" added to tty-testing

[gregkh]

This is a note to let you know that I've just added the patch titled

    tty: serial: samsung_tty: Fix a memory leak in

to my tty git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the tty-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


From a9c09546e903f1068acfa38e1ee18bded7114b37 Mon Sep 17 00:00:00 2001
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Sat, 10 Jun 2023 17:59:25 +0200
Subject: tty: serial: samsung_tty: Fix a memory leak in
 s3c24xx_serial_getclk() in case of error

If clk_get_rate() fails, the clk that has just been allocated needs to be
freed.

Cc: <stable@vger.kernel.org> # v3.3+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Message-ID: <e4baf6039368f52e5a5453982ddcb9a330fc689e.1686412569.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/samsung_tty.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 2a7520ad3abd..a92a23e1964e 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1459,8 +1459,12 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			continue;
 
 		rate = clk_get_rate(clk);
-		if (!rate)
+		if (!rate) {
+			dev_err(ourport->port.dev,
+				"Failed to get clock rate for %s.\n", clkname);
+			clk_put(clk);
 			continue;
+		}
 
 		if (ourport->info->has_divslot) {
 			unsigned long div = rate / req_baud;
-- 
2.41.0

patch "tty: serial: samsung_tty: Fix a memory leak in" added to tty-testing

[gregkh]

This is a note to let you know that I've just added the patch titled

    tty: serial: samsung_tty: Fix a memory leak in

to my tty git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the tty-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


From 832e231cff476102e8204a9e7bddfe5c6154a375 Mon Sep 17 00:00:00 2001
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Sat, 10 Jun 2023 17:59:26 +0200
Subject: tty: serial: samsung_tty: Fix a memory leak in
 s3c24xx_serial_getclk() when iterating clk

When the best clk is searched, we iterate over all possible clk.

If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.

Cc: <stable@vger.kernel.org> # v3.3+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Message-ID: <cf3e0053d2fc7391b2d906a86cd01a5ef15fb9dc.1686412569.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/samsung_tty.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index a92a23e1964e..0b37019820b4 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1490,10 +1490,18 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			calc_deviation = -calc_deviation;
 
 		if (calc_deviation < deviation) {
+			/*
+			 * If we find a better clk, release the previous one, if
+			 * any.
+			 */
+			if (!IS_ERR(*best_clk))
+				clk_put(*best_clk);
 			*best_clk = clk;
 			best_quot = quot;
 			*clk_num = cnt;
 			deviation = calc_deviation;
+		} else {
+			clk_put(clk);
 		}
 	}
 
-- 
2.41.0

patch "tty: serial: samsung_tty: Fix a memory leak in" added to tty-next

[gregkh]

This is a note to let you know that I've just added the patch titled

    tty: serial: samsung_tty: Fix a memory leak in

to my tty git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


From a9c09546e903f1068acfa38e1ee18bded7114b37 Mon Sep 17 00:00:00 2001
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Sat, 10 Jun 2023 17:59:25 +0200
Subject: tty: serial: samsung_tty: Fix a memory leak in
 s3c24xx_serial_getclk() in case of error

If clk_get_rate() fails, the clk that has just been allocated needs to be
freed.

Cc: <stable@vger.kernel.org> # v3.3+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Message-ID: <e4baf6039368f52e5a5453982ddcb9a330fc689e.1686412569.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/samsung_tty.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 2a7520ad3abd..a92a23e1964e 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1459,8 +1459,12 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			continue;
 
 		rate = clk_get_rate(clk);
-		if (!rate)
+		if (!rate) {
+			dev_err(ourport->port.dev,
+				"Failed to get clock rate for %s.\n", clkname);
+			clk_put(clk);
 			continue;
+		}
 
 		if (ourport->info->has_divslot) {
 			unsigned long div = rate / req_baud;
-- 
2.41.0

patch "tty: serial: samsung_tty: Fix a memory leak in" added to tty-next

[gregkh]

This is a note to let you know that I've just added the patch titled

    tty: serial: samsung_tty: Fix a memory leak in

to my tty git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


From 832e231cff476102e8204a9e7bddfe5c6154a375 Mon Sep 17 00:00:00 2001
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Sat, 10 Jun 2023 17:59:26 +0200
Subject: tty: serial: samsung_tty: Fix a memory leak in
 s3c24xx_serial_getclk() when iterating clk

When the best clk is searched, we iterate over all possible clk.

If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.

Cc: <stable@vger.kernel.org> # v3.3+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Message-ID: <cf3e0053d2fc7391b2d906a86cd01a5ef15fb9dc.1686412569.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/samsung_tty.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index a92a23e1964e..0b37019820b4 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1490,10 +1490,18 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			calc_deviation = -calc_deviation;
 
 		if (calc_deviation < deviation) {
+			/*
+			 * If we find a better clk, release the previous one, if
+			 * any.
+			 */
+			if (!IS_ERR(*best_clk))
+				clk_put(*best_clk);
 			*best_clk = clk;
 			best_quot = quot;
 			*clk_num = cnt;
 			deviation = calc_deviation;
+		} else {
+			clk_put(clk);
 		}
 	}
 
-- 
2.41.0