This patch fixes the following issues:
1. memstick_free_host() will free the host, so the use of ms_dev(host) after
it will be a problem. To fix this, move memstick_free_host() after when we
are done with ms_dev(host).
2. if something bad happens in memstick_add_host() and we end up taking
err_out in rtsx_usb_ms_drv_probe(), we'd better avoid running rtsx_usb_ms_drv_remove()
3. In rtsx_usb_ms_drv_remove(), pm need to be disabled before we remove
and free host otherwise memstick_check will be called and UAF will
happen.
[ 11.351173] BUG: KASAN: use-after-free in rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
[ 11.357077] rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
[ 11.357376] platform_remove+0x2a/0x50
[ 11.367531] Freed by task 298:
[ 11.368537] kfree+0xa4/0x2a0
[ 11.368711] device_release+0x51/0xe0
[ 11.368905] kobject_put+0xa2/0x120
[ 11.369090] rtsx_usb_ms_drv_remove+0x8c/0x140 [rtsx_usb_ms]
[ 11.369386] platform_remove+0x2a/0x50
[ 12.038408] BUG: KASAN: use-after-free in __mutex_lock.isra.0+0x3ec/0x7c0
[ 12.045432] mutex_lock+0xc9/0xd0
[ 12.046080] memstick_check+0x6a/0x578 [memstick]
[ 12.046509] process_one_work+0x46d/0x750
[ 12.052107] Freed by task 297:
[ 12.053115] kfree+0xa4/0x2a0
[ 12.053272] device_release+0x51/0xe0
[ 12.053463] kobject_put+0xa2/0x120
[ 12.053647] rtsx_usb_ms_drv_remove+0xc4/0x140 [rtsx_usb_ms]
[ 12.053939] platform_remove+0x2a/0x50
Signed-off-by: Tong Zhang <[email protected]>
---
drivers/memstick/host/rtsx_usb_ms.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c
index 102dbb8080da..851643d007b7 100644
--- a/drivers/memstick/host/rtsx_usb_ms.c
+++ b/drivers/memstick/host/rtsx_usb_ms.c
@@ -799,9 +799,10 @@ static int rtsx_usb_ms_drv_probe(struct platform_device *pdev)
return 0;
err_out:
- memstick_free_host(msh);
pm_runtime_disable(ms_dev(host));
pm_runtime_put_noidle(ms_dev(host));
+ memstick_free_host(msh);
+ platform_set_drvdata(pdev, NULL);
return err;
}
@@ -811,6 +812,8 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
struct memstick_host *msh = host->msh;
int err;
+ if (!host)
+ return 0;
host->eject = true;
cancel_work_sync(&host->handle_req);
@@ -828,9 +831,6 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
}
mutex_unlock(&host->host_mutex);
- memstick_remove_host(msh);
- memstick_free_host(msh);
-
/* Balance possible unbalanced usage count
* e.g. unconditional module removal
*/
@@ -838,10 +838,11 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
pm_runtime_put(ms_dev(host));
pm_runtime_disable(ms_dev(host));
- platform_set_drvdata(pdev, NULL);
-
+ memstick_remove_host(msh);
dev_dbg(ms_dev(host),
": Realtek USB Memstick controller has been removed\n");
+ memstick_free_host(msh);
+ platform_set_drvdata(pdev, NULL);
return 0;
}
--
2.25.1
On Sun, 9 May 2021 at 23:54, Tong Zhang <[email protected]> wrote:
>
> This patch fixes the following issues:
> 1. memstick_free_host() will free the host, so the use of ms_dev(host) after
> it will be a problem. To fix this, move memstick_free_host() after when we
> are done with ms_dev(host).
> 2. if something bad happens in memstick_add_host() and we end up taking
> err_out in rtsx_usb_ms_drv_probe(), we'd better avoid running rtsx_usb_ms_drv_remove()
If the ->probe() function returns a negative error code, the driver
core will not invoke the corresponding ->remove() callback.
Looks like you may want to double check that ->probe() doesn't return
0, even in case of failure.
> 3. In rtsx_usb_ms_drv_remove(), pm need to be disabled before we remove
> and free host otherwise memstick_check will be called and UAF will
> happen.
>
> [ 11.351173] BUG: KASAN: use-after-free in rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
> [ 11.357077] rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
> [ 11.357376] platform_remove+0x2a/0x50
> [ 11.367531] Freed by task 298:
> [ 11.368537] kfree+0xa4/0x2a0
> [ 11.368711] device_release+0x51/0xe0
> [ 11.368905] kobject_put+0xa2/0x120
> [ 11.369090] rtsx_usb_ms_drv_remove+0x8c/0x140 [rtsx_usb_ms]
> [ 11.369386] platform_remove+0x2a/0x50
>
> [ 12.038408] BUG: KASAN: use-after-free in __mutex_lock.isra.0+0x3ec/0x7c0
> [ 12.045432] mutex_lock+0xc9/0xd0
> [ 12.046080] memstick_check+0x6a/0x578 [memstick]
> [ 12.046509] process_one_work+0x46d/0x750
> [ 12.052107] Freed by task 297:
> [ 12.053115] kfree+0xa4/0x2a0
> [ 12.053272] device_release+0x51/0xe0
> [ 12.053463] kobject_put+0xa2/0x120
> [ 12.053647] rtsx_usb_ms_drv_remove+0xc4/0x140 [rtsx_usb_ms]
> [ 12.053939] platform_remove+0x2a/0x50
>
> Signed-off-by: Tong Zhang <[email protected]>
> ---
> drivers/memstick/host/rtsx_usb_ms.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c
> index 102dbb8080da..851643d007b7 100644
> --- a/drivers/memstick/host/rtsx_usb_ms.c
> +++ b/drivers/memstick/host/rtsx_usb_ms.c
> @@ -799,9 +799,10 @@ static int rtsx_usb_ms_drv_probe(struct platform_device *pdev)
>
> return 0;
> err_out:
> - memstick_free_host(msh);
> pm_runtime_disable(ms_dev(host));
> pm_runtime_put_noidle(ms_dev(host));
> + memstick_free_host(msh);
> + platform_set_drvdata(pdev, NULL);
> return err;
> }
>
> @@ -811,6 +812,8 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> struct memstick_host *msh = host->msh;
> int err;
>
> + if (!host)
> + return 0;
According to my comment above. You should not reach this point, unless
->probe() was successful and returned 0.
> host->eject = true;
> cancel_work_sync(&host->handle_req);
>
> @@ -828,9 +831,6 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> }
> mutex_unlock(&host->host_mutex);
>
> - memstick_remove_host(msh);
> - memstick_free_host(msh);
> -
> /* Balance possible unbalanced usage count
> * e.g. unconditional module removal
> */
> @@ -838,10 +838,11 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> pm_runtime_put(ms_dev(host));
>
> pm_runtime_disable(ms_dev(host));
> - platform_set_drvdata(pdev, NULL);
> -
> + memstick_remove_host(msh);
> dev_dbg(ms_dev(host),
> ": Realtek USB Memstick controller has been removed\n");
> + memstick_free_host(msh);
> + platform_set_drvdata(pdev, NULL);
>
> return 0;
> }
> --
> 2.25.1
>
Besides the above, the change looks reasonable to me.
Kind regards
Uffe
This patch fixes the following issues:
1. memstick_free_host() will free the host, so the use of ms_dev(host) after
it will be a problem. To fix this, move memstick_free_host() after when we
are done with ms_dev(host).
2. In rtsx_usb_ms_drv_remove(), pm need to be disabled before we remove
and free host otherwise memstick_check will be called and UAF will
happen.
[ 11.351173] BUG: KASAN: use-after-free in rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
[ 11.357077] rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
[ 11.357376] platform_remove+0x2a/0x50
[ 11.367531] Freed by task 298:
[ 11.368537] kfree+0xa4/0x2a0
[ 11.368711] device_release+0x51/0xe0
[ 11.368905] kobject_put+0xa2/0x120
[ 11.369090] rtsx_usb_ms_drv_remove+0x8c/0x140 [rtsx_usb_ms]
[ 11.369386] platform_remove+0x2a/0x50
[ 12.038408] BUG: KASAN: use-after-free in __mutex_lock.isra.0+0x3ec/0x7c0
[ 12.045432] mutex_lock+0xc9/0xd0
[ 12.046080] memstick_check+0x6a/0x578 [memstick]
[ 12.046509] process_one_work+0x46d/0x750
[ 12.052107] Freed by task 297:
[ 12.053115] kfree+0xa4/0x2a0
[ 12.053272] device_release+0x51/0xe0
[ 12.053463] kobject_put+0xa2/0x120
[ 12.053647] rtsx_usb_ms_drv_remove+0xc4/0x140 [rtsx_usb_ms]
[ 12.053939] platform_remove+0x2a/0x50
Signed-off-by: Tong Zhang <[email protected]>
Co-Developed-by: Ulf Hansson <[email protected]>
---
v2: remove useless code in err_out label
drivers/memstick/host/rtsx_usb_ms.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c
index 102dbb8080da..29271ad4728a 100644
--- a/drivers/memstick/host/rtsx_usb_ms.c
+++ b/drivers/memstick/host/rtsx_usb_ms.c
@@ -799,9 +799,9 @@ static int rtsx_usb_ms_drv_probe(struct platform_device *pdev)
return 0;
err_out:
- memstick_free_host(msh);
pm_runtime_disable(ms_dev(host));
pm_runtime_put_noidle(ms_dev(host));
+ memstick_free_host(msh);
return err;
}
@@ -828,9 +828,6 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
}
mutex_unlock(&host->host_mutex);
- memstick_remove_host(msh);
- memstick_free_host(msh);
-
/* Balance possible unbalanced usage count
* e.g. unconditional module removal
*/
@@ -838,10 +835,11 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
pm_runtime_put(ms_dev(host));
pm_runtime_disable(ms_dev(host));
- platform_set_drvdata(pdev, NULL);
-
+ memstick_remove_host(msh);
dev_dbg(ms_dev(host),
": Realtek USB Memstick controller has been removed\n");
+ memstick_free_host(msh);
+ platform_set_drvdata(pdev, NULL);
return 0;
}
--
2.25.1
On Tue, May 11, 2021 at 3:40 AM Ulf Hansson <[email protected]> wrote:
>
> On Sun, 9 May 2021 at 23:54, Tong Zhang <[email protected]> wrote:
> >
> > This patch fixes the following issues:
> > 1. memstick_free_host() will free the host, so the use of ms_dev(host) after
> > it will be a problem. To fix this, move memstick_free_host() after when we
> > are done with ms_dev(host).
> > 2. if something bad happens in memstick_add_host() and we end up taking
> > err_out in rtsx_usb_ms_drv_probe(), we'd better avoid running rtsx_usb_ms_drv_remove()
>
> If the ->probe() function returns a negative error code, the driver
> core will not invoke the corresponding ->remove() callback.
>
> Looks like you may want to double check that ->probe() doesn't return
> 0, even in case of failure.
>
> > 3. In rtsx_usb_ms_drv_remove(), pm need to be disabled before we remove
> > and free host otherwise memstick_check will be called and UAF will
> > happen.
> >
> > [ 11.351173] BUG: KASAN: use-after-free in rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
> > [ 11.357077] rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
> > [ 11.357376] platform_remove+0x2a/0x50
> > [ 11.367531] Freed by task 298:
> > [ 11.368537] kfree+0xa4/0x2a0
> > [ 11.368711] device_release+0x51/0xe0
> > [ 11.368905] kobject_put+0xa2/0x120
> > [ 11.369090] rtsx_usb_ms_drv_remove+0x8c/0x140 [rtsx_usb_ms]
> > [ 11.369386] platform_remove+0x2a/0x50
> >
> > [ 12.038408] BUG: KASAN: use-after-free in __mutex_lock.isra.0+0x3ec/0x7c0
> > [ 12.045432] mutex_lock+0xc9/0xd0
> > [ 12.046080] memstick_check+0x6a/0x578 [memstick]
> > [ 12.046509] process_one_work+0x46d/0x750
> > [ 12.052107] Freed by task 297:
> > [ 12.053115] kfree+0xa4/0x2a0
> > [ 12.053272] device_release+0x51/0xe0
> > [ 12.053463] kobject_put+0xa2/0x120
> > [ 12.053647] rtsx_usb_ms_drv_remove+0xc4/0x140 [rtsx_usb_ms]
> > [ 12.053939] platform_remove+0x2a/0x50
> >
> > Signed-off-by: Tong Zhang <[email protected]>
> > ---
> > drivers/memstick/host/rtsx_usb_ms.c | 13 +++++++------
> > 1 file changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c
> > index 102dbb8080da..851643d007b7 100644
> > --- a/drivers/memstick/host/rtsx_usb_ms.c
> > +++ b/drivers/memstick/host/rtsx_usb_ms.c
> > @@ -799,9 +799,10 @@ static int rtsx_usb_ms_drv_probe(struct platform_device *pdev)
> >
> > return 0;
> > err_out:
> > - memstick_free_host(msh);
> > pm_runtime_disable(ms_dev(host));
> > pm_runtime_put_noidle(ms_dev(host));
> > + memstick_free_host(msh);
> > + platform_set_drvdata(pdev, NULL);
> > return err;
> > }
> >
> > @@ -811,6 +812,8 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> > struct memstick_host *msh = host->msh;
> > int err;
> >
> > + if (!host)
> > + return 0;
>
> According to my comment above. You should not reach this point, unless
> ->probe() was successful and returned 0.
>
> > host->eject = true;
> > cancel_work_sync(&host->handle_req);
> >
> > @@ -828,9 +831,6 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> > }
> > mutex_unlock(&host->host_mutex);
> >
> > - memstick_remove_host(msh);
> > - memstick_free_host(msh);
> > -
> > /* Balance possible unbalanced usage count
> > * e.g. unconditional module removal
> > */
> > @@ -838,10 +838,11 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> > pm_runtime_put(ms_dev(host));
> >
> > pm_runtime_disable(ms_dev(host));
> > - platform_set_drvdata(pdev, NULL);
> > -
> > + memstick_remove_host(msh);
> > dev_dbg(ms_dev(host),
> > ": Realtek USB Memstick controller has been removed\n");
> > + memstick_free_host(msh);
> > + platform_set_drvdata(pdev, NULL);
> >
> > return 0;
> > }
> > --
> > 2.25.1
> >
>
> Besides the above, the change looks reasonable to me.
>
> Kind regards
> Uffe
Thanks Uffe!
I modified the patch as suggested and sent as v2.
Best,
- Tong
On Tue, 11 May 2021 at 18:40, Tong Zhang <[email protected]> wrote:
>
> This patch fixes the following issues:
> 1. memstick_free_host() will free the host, so the use of ms_dev(host) after
> it will be a problem. To fix this, move memstick_free_host() after when we
> are done with ms_dev(host).
> 2. In rtsx_usb_ms_drv_remove(), pm need to be disabled before we remove
> and free host otherwise memstick_check will be called and UAF will
> happen.
>
> [ 11.351173] BUG: KASAN: use-after-free in rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
> [ 11.357077] rtsx_usb_ms_drv_remove+0x94/0x140 [rtsx_usb_ms]
> [ 11.357376] platform_remove+0x2a/0x50
> [ 11.367531] Freed by task 298:
> [ 11.368537] kfree+0xa4/0x2a0
> [ 11.368711] device_release+0x51/0xe0
> [ 11.368905] kobject_put+0xa2/0x120
> [ 11.369090] rtsx_usb_ms_drv_remove+0x8c/0x140 [rtsx_usb_ms]
> [ 11.369386] platform_remove+0x2a/0x50
>
> [ 12.038408] BUG: KASAN: use-after-free in __mutex_lock.isra.0+0x3ec/0x7c0
> [ 12.045432] mutex_lock+0xc9/0xd0
> [ 12.046080] memstick_check+0x6a/0x578 [memstick]
> [ 12.046509] process_one_work+0x46d/0x750
> [ 12.052107] Freed by task 297:
> [ 12.053115] kfree+0xa4/0x2a0
> [ 12.053272] device_release+0x51/0xe0
> [ 12.053463] kobject_put+0xa2/0x120
> [ 12.053647] rtsx_usb_ms_drv_remove+0xc4/0x140 [rtsx_usb_ms]
> [ 12.053939] platform_remove+0x2a/0x50
>
> Signed-off-by: Tong Zhang <[email protected]>
> Co-Developed-by: Ulf Hansson <[email protected]>
Applied for next, thanks!
Kind regards
Uffe
> ---
> v2: remove useless code in err_out label
>
> drivers/memstick/host/rtsx_usb_ms.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c
> index 102dbb8080da..29271ad4728a 100644
> --- a/drivers/memstick/host/rtsx_usb_ms.c
> +++ b/drivers/memstick/host/rtsx_usb_ms.c
> @@ -799,9 +799,9 @@ static int rtsx_usb_ms_drv_probe(struct platform_device *pdev)
>
> return 0;
> err_out:
> - memstick_free_host(msh);
> pm_runtime_disable(ms_dev(host));
> pm_runtime_put_noidle(ms_dev(host));
> + memstick_free_host(msh);
> return err;
> }
>
> @@ -828,9 +828,6 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> }
> mutex_unlock(&host->host_mutex);
>
> - memstick_remove_host(msh);
> - memstick_free_host(msh);
> -
> /* Balance possible unbalanced usage count
> * e.g. unconditional module removal
> */
> @@ -838,10 +835,11 @@ static int rtsx_usb_ms_drv_remove(struct platform_device *pdev)
> pm_runtime_put(ms_dev(host));
>
> pm_runtime_disable(ms_dev(host));
> - platform_set_drvdata(pdev, NULL);
> -
> + memstick_remove_host(msh);
> dev_dbg(ms_dev(host),
> ": Realtek USB Memstick controller has been removed\n");
> + memstick_free_host(msh);
> + platform_set_drvdata(pdev, NULL);
>
> return 0;
> }
> --
> 2.25.1
>