* Re: [RESEND PATCH] memstick: fix memory leak if card device is never registered
2023-04-01 20:03 [RESEND PATCH] memstick: fix memory leak if card device is never registered Greg Kroah-Hartman
@ 2023-04-03 14:14 ` Mirsad Goran Todorovac
2023-04-04 11:54 ` Ulf Hansson
1 sibling, 0 replies; 4+ messages in thread
From: Mirsad Goran Todorovac @ 2023-04-03 14:14 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-mmc
Cc: linux-kernel, Maxim Levitsky, Alex Dubov, Ulf Hansson,
Rafael J. Wysocki, Hans de Goede, Kay Sievers, stable,
Bagas Sanjaya, Linux Kbuild mailing list
On 1.4.2023. 22:03, Greg Kroah-Hartman wrote:
> When calling dev_set_name() memory is allocated for the name for the
> struct device. Once that structure device is registered, or attempted
> to be registerd, with the driver core, the driver core will handle
> cleaning up that memory when the device is removed from the system.
>
> Unfortunatly for the memstick code, there is an error path that causes
> the struct device to never be registered, and so the memory allocated in
> dev_set_name will be leaked. Fix that leak by manually freeing it right
> before the memory for the device is freed.
>
> Cc: Maxim Levitsky <maximlevitsky@gmail.com>
> Cc: Alex Dubov <oakad@yahoo.com>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Hans de Goede <hdegoede@redhat.com>
> Cc: Kay Sievers <kay.sievers@vrfy.org>
> Cc: linux-mmc@vger.kernel.org
> Fixes: 0252c3b4f018 ("memstick: struct device - replace bus_id with dev_name(),
> Cc: stable <stable@kernel.org>
> Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Co-developed-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
> ---
> RESEND as the first version had a corrupted message id and never made it
> to the mailing lists or lore.kernel.org
>
> drivers/memstick/core/memstick.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/memstick/core/memstick.c b/drivers/memstick/core/memstick.c
> index bf7667845459..bbfaf6536903 100644
> --- a/drivers/memstick/core/memstick.c
> +++ b/drivers/memstick/core/memstick.c
> @@ -410,6 +410,7 @@ static struct memstick_dev *memstick_alloc_card(struct memstick_host *host)
> return card;
> err_out:
> host->card = old_card;
> + kfree_const(card->dev.kobj.name);
> kfree(card);
> return NULL;
> }
> @@ -468,8 +469,10 @@ static void memstick_check(struct work_struct *work)
> put_device(&card->dev);
> host->card = NULL;
> }
> - } else
> + } else {
> + kfree_const(card->dev.kobj.name);
> kfree(card);
> + }
> }
>
> out_power_off:
FYI, the applied patch tested OK, no memstick leaks:
[root@pc-mtodorov kernel]# uname -rms
Linux 6.3.0-rc5-mt-20230401-00007-g268a637be362 x86_64
[root@pc-mtodorov kernel]# echo scan > /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# cat /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# echo scan > /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# cat /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# echo scan > /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# cat /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# echo scan > /sys/kernel/debug/kmemleak
[root@pc-mtodorov kernel]# cat /sys/kernel/debug/kmemleak
What was applied is:
mtodorov@domac:~/linux/kernel/linux_torvalds$ git diff master..origin/master | head -24
diff --git a/drivers/memstick/core/memstick.c b/drivers/memstick/core/memstick.c
index bbfaf6536903..bf7667845459 100644
--- a/drivers/memstick/core/memstick.c
+++ b/drivers/memstick/core/memstick.c
@@ -410,7 +410,6 @@ static struct memstick_dev *memstick_alloc_card(struct memstick_host *host)
return card;
err_out:
host->card = old_card;
- kfree_const(card->dev.kobj.name);
kfree(card);
return NULL;
}
@@ -469,10 +468,8 @@ static void memstick_check(struct work_struct *work)
put_device(&card->dev);
host->card = NULL;
}
- } else {
- kfree_const(card->dev.kobj.name);
+ } else
kfree(card);
- }
}
out_power_off:
APPENDIX
However, please note that the patch SHA-1's truncated to 12 chars might not
be the same on the other systems, so the build ID says nothing about which
mainline kernel had the patches been applied against. So `uname -rms` is
telling pretty nothing about which kernel I'm running, except that it helps
me distinguish between the builds.
Nothing to prove that:
- I am not testing the wrong kernel and
- that the right patches have been applied.
Changing CONFIG_LOCALVERSION causes copious recompilations, even with ccache
it takes about 4x the time needed to compile CONFIG_LOCALVERSION_AUTO=y.
Do I make any sense with this?
I am adding Cc: to Mr. Bagas, for we spoke already about kernel versioning
in the case of manually applied patches.
Regards,
Mirsad
--
Mirsad Todorovac
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb
Republic of Croatia, the European Union
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [RESEND PATCH] memstick: fix memory leak if card device is never registered
2023-04-01 20:03 [RESEND PATCH] memstick: fix memory leak if card device is never registered Greg Kroah-Hartman
2023-04-03 14:14 ` Mirsad Goran Todorovac
@ 2023-04-04 11:54 ` Ulf Hansson
2023-04-04 12:03 ` Greg Kroah-Hartman
1 sibling, 1 reply; 4+ messages in thread
From: Ulf Hansson @ 2023-04-04 11:54 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: linux-mmc, linux-kernel, Maxim Levitsky, Alex Dubov,
Rafael J. Wysocki, Hans de Goede, Kay Sievers, stable,
Mirsad Goran Todorovac
On Sat, 1 Apr 2023 at 22:03, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> When calling dev_set_name() memory is allocated for the name for the
> struct device. Once that structure device is registered, or attempted
> to be registerd, with the driver core, the driver core will handle
> cleaning up that memory when the device is removed from the system.
>
> Unfortunatly for the memstick code, there is an error path that causes
> the struct device to never be registered, and so the memory allocated in
> dev_set_name will be leaked. Fix that leak by manually freeing it right
> before the memory for the device is freed.
>
> Cc: Maxim Levitsky <maximlevitsky@gmail.com>
> Cc: Alex Dubov <oakad@yahoo.com>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Hans de Goede <hdegoede@redhat.com>
> Cc: Kay Sievers <kay.sievers@vrfy.org>
> Cc: linux-mmc@vger.kernel.org
> Fixes: 0252c3b4f018 ("memstick: struct device - replace bus_id with dev_name(),
> Cc: stable <stable@kernel.org>
> Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Co-developed-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Applied for fixes and by adding Mirsad's sob tag (according to the
other thread [1]), thanks!
Kind regards
Uffe
[1]
https://lore.kernel.org/lkml/c059f486-98a6-aecd-c135-c033612e6b4f@alu.unizg.hr/
> ---
> RESEND as the first version had a corrupted message id and never made it
> to the mailing lists or lore.kernel.org
>
> drivers/memstick/core/memstick.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/memstick/core/memstick.c b/drivers/memstick/core/memstick.c
> index bf7667845459..bbfaf6536903 100644
> --- a/drivers/memstick/core/memstick.c
> +++ b/drivers/memstick/core/memstick.c
> @@ -410,6 +410,7 @@ static struct memstick_dev *memstick_alloc_card(struct memstick_host *host)
> return card;
> err_out:
> host->card = old_card;
> + kfree_const(card->dev.kobj.name);
> kfree(card);
> return NULL;
> }
> @@ -468,8 +469,10 @@ static void memstick_check(struct work_struct *work)
> put_device(&card->dev);
> host->card = NULL;
> }
> - } else
> + } else {
> + kfree_const(card->dev.kobj.name);
> kfree(card);
> + }
> }
>
> out_power_off:
> --
> 2.40.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread