firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()

[PATCH v2] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()

Posted by Xinqi Zhang 1 month, 1 week ago

The scmi_dev->name is released prematurely in __scmi_device_destroy(),
which causes slab-use-after-free when accessing scmi_dev->name in
scmi_bus_notifier(). So move the release of scmi_dev->name to
scmi_device_release() to avoid slab-use-after-free.

==================================================================
BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1

CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1
Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT)
Call trace:
 dump_backtrace+0x94/0x114
 show_stack+0x18/0x24
 dump_stack_lvl+0x48/0x60
 print_report+0xf4/0x5b0
 kasan_report+0xa4/0xec
 __asan_report_load1_noabort+0x20/0x2c
 strncmp+0xe4/0xec
 scmi_bus_notifier+0x5c/0x54c
 notifier_call_chain+0xb4/0x31c
 blocking_notifier_call_chain+0x68/0x9c
 bus_notify+0x54/0x78
 device_del+0x1bc/0x840
 device_unregister+0x20/0xb4
 __scmi_device_destroy+0xac/0x280
 scmi_device_destroy+0x94/0xd0
 scmi_chan_setup+0x524/0x750
 scmi_probe+0x7fc/0x1508
 platform_probe+0xc4/0x19c
 really_probe+0x32c/0x99c
 __driver_probe_device+0x15c/0x3c4
 driver_probe_device+0x5c/0x170
 __driver_attach+0x1c8/0x440
 bus_for_each_dev+0xf4/0x178
 driver_attach+0x3c/0x58
 bus_add_driver+0x234/0x4d4
 driver_register+0xf4/0x3c0
 __platform_driver_register+0x60/0x88
 scmi_driver_init+0xb0/0x104
 do_one_initcall+0xb4/0x664
 kernel_init_freeable+0x3c8/0x894
 kernel_init+0x24/0x1e8
 ret_from_fork+0x10/0x20

Allocated by task 1:
 kasan_save_stack+0x2c/0x54
 kasan_set_track+0x2c/0x40
 kasan_save_alloc_info+0x24/0x34
 __kasan_kmalloc+0xa0/0xb8
 __kmalloc_node_track_caller+0x6c/0x104
 kstrdup+0x48/0x84
 kstrdup_const+0x34/0x40
 __scmi_device_create.part.0+0x8c/0x408
 scmi_device_create+0x104/0x370
 scmi_chan_setup+0x2a0/0x750
 scmi_probe+0x7fc/0x1508
 platform_probe+0xc4/0x19c
 really_probe+0x32c/0x99c
 __driver_probe_device+0x15c/0x3c4
 driver_probe_device+0x5c/0x170
 __driver_attach+0x1c8/0x440
 bus_for_each_dev+0xf4/0x178
 driver_attach+0x3c/0x58
 bus_add_driver+0x234/0x4d4
 driver_register+0xf4/0x3c0
 __platform_driver_register+0x60/0x88
 scmi_driver_init+0xb0/0x104
 do_one_initcall+0xb4/0x664
 kernel_init_freeable+0x3c8/0x894
 kernel_init+0x24/0x1e8
 ret_from_fork+0x10/0x20

Freed by task 1:
 kasan_save_stack+0x2c/0x54
 kasan_set_track+0x2c/0x40
 kasan_save_free_info+0x38/0x5c
 __kasan_slab_free+0xe8/0x164
 __kmem_cache_free+0x11c/0x230
 kfree+0x70/0x130
 kfree_const+0x20/0x40
 __scmi_device_destroy+0x70/0x280
 scmi_device_destroy+0x94/0xd0
 scmi_chan_setup+0x524/0x750
 scmi_probe+0x7fc/0x1508
 platform_probe+0xc4/0x19c
 really_probe+0x32c/0x99c
 __driver_probe_device+0x15c/0x3c4
 driver_probe_device+0x5c/0x170
 __driver_attach+0x1c8/0x440
 bus_for_each_dev+0xf4/0x178
 driver_attach+0x3c/0x58
 bus_add_driver+0x234/0x4d4
 driver_register+0xf4/0x3c0
 __platform_driver_register+0x60/0x88
 scmi_driver_init+0xb0/0x104
 do_one_initcall+0xb4/0x664
 kernel_init_freeable+0x3c8/0x894
 kernel_init+0x24/0x1e8
 ret_from_fork+0x10/0x20

Fixes: ee7a9c9f67c5 ("firmware: arm_scmi: Add support for multiple device per protocol")
Signed-off-by: Xinqi Zhang <quic_xinqzhan@quicinc.com>
---
Changes in v2:
- Standardize commit messages and add Fixes tags.
- Link to v1: https://lore.kernel.org/r/20241015-fix-arm-scmi-slab-use-after-free-v1-1-b006eba9c8df@quicinc.com
---
 drivers/firmware/arm_scmi/bus.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 96b2e5f9a8ef0386525f9d91d2925e7e6d48ac28..157172a5f2b577ce4f04425f967f548230c1ebed 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -325,7 +325,10 @@ EXPORT_SYMBOL_GPL(scmi_driver_unregister);
 
 static void scmi_device_release(struct device *dev)
 {
-	kfree(to_scmi_dev(dev));
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	kfree_const(scmi_dev->name);
+	kfree(scmi_dev);
 }
 
 static void __scmi_device_destroy(struct scmi_device *scmi_dev)
@@ -338,7 +341,6 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev)
 	if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
 		atomic_set(&scmi_syspower_registered, 0);
 
-	kfree_const(scmi_dev->name);
 	ida_free(&scmi_bus_id, scmi_dev->id);
 	device_unregister(&scmi_dev->dev);
 }
@@ -410,7 +412,6 @@ __scmi_device_create(struct device_node *np, struct device *parent,
 
 	return scmi_dev;
 put_dev:
-	kfree_const(scmi_dev->name);
 	put_device(&scmi_dev->dev);
 	ida_free(&scmi_bus_id, id);
 	return NULL;

---
base-commit: eca631b8fe808748d7585059c4307005ca5c5820
change-id: 20241015-fix-arm-scmi-slab-use-after-free-74e358b3c90c

Best regards,
-- 
Xinqi Zhang <quic_xinqzhan@quicinc.com>

Re: [PATCH v2] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()

Posted by Sudeep Holla 3 weeks, 5 days ago

On Wed, 16 Oct 2024 14:13:38 +0800, Xinqi Zhang wrote:
> The scmi_dev->name is released prematurely in __scmi_device_destroy(),
> which causes slab-use-after-free when accessing scmi_dev->name in
> scmi_bus_notifier(). So move the release of scmi_dev->name to
> scmi_device_release() to avoid slab-use-after-free.
> 
> ==================================================================
> BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
> Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1
> 
> [...]

Applied to sudeep.holla/linux (for-next/scmi/fixes), thanks!

[1/1] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()
      https://git.kernel.org/sudeep.holla/c/295416091e44
--
Regards,
Sudeep

Re: [PATCH v2] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()

Posted by Sudeep Holla 4 weeks, 1 day ago

On Wed, 16 Oct 2024 14:13:38 +0800, Xinqi Zhang wrote:
> The scmi_dev->name is released prematurely in __scmi_device_destroy(),
> which causes slab-use-after-free when accessing scmi_dev->name in
> scmi_bus_notifier(). So move the release of scmi_dev->name to
> scmi_device_release() to avoid slab-use-after-free.
> 
> ==================================================================
> BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
> Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1
> 
> [...]

Applied to sudeep.holla/linux (for-next/scmi/fixes), thanks!

[1/1] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()
      https://git.kernel.org/sudeep.holla/c/295416091e44
--
Regards,
Sudeep

Re: [PATCH v2] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()

Posted by Cristian Marussi 1 month, 1 week ago

On Wed, Oct 16, 2024 at 02:13:38PM +0800, Xinqi Zhang wrote:
> The scmi_dev->name is released prematurely in __scmi_device_destroy(),
> which causes slab-use-after-free when accessing scmi_dev->name in
> scmi_bus_notifier(). So move the release of scmi_dev->name to
> scmi_device_release() to avoid slab-use-after-free.

LGTM.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>

Thanks,
Cristian

Re: [PATCH v2] firmware: arm_scmi: fix slab-use-after-free in scmi_bus_notifier()

Posted by Bjorn Andersson 1 month, 1 week ago

On Wed, Oct 16, 2024 at 02:13:38PM GMT, Xinqi Zhang wrote:
> The scmi_dev->name is released prematurely in __scmi_device_destroy(),
> which causes slab-use-after-free when accessing scmi_dev->name in
> scmi_bus_notifier(). So move the release of scmi_dev->name to
> scmi_device_release() to avoid slab-use-after-free.
> 
> ==================================================================
> BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
> Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1
> 
> CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1
> Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT)
> Call trace:
>  dump_backtrace+0x94/0x114
>  show_stack+0x18/0x24
>  dump_stack_lvl+0x48/0x60
>  print_report+0xf4/0x5b0
>  kasan_report+0xa4/0xec
>  __asan_report_load1_noabort+0x20/0x2c
>  strncmp+0xe4/0xec
>  scmi_bus_notifier+0x5c/0x54c
>  notifier_call_chain+0xb4/0x31c
>  blocking_notifier_call_chain+0x68/0x9c
>  bus_notify+0x54/0x78
>  device_del+0x1bc/0x840
>  device_unregister+0x20/0xb4
>  __scmi_device_destroy+0xac/0x280
>  scmi_device_destroy+0x94/0xd0
>  scmi_chan_setup+0x524/0x750
>  scmi_probe+0x7fc/0x1508
>  platform_probe+0xc4/0x19c
>  really_probe+0x32c/0x99c
>  __driver_probe_device+0x15c/0x3c4
>  driver_probe_device+0x5c/0x170
>  __driver_attach+0x1c8/0x440
>  bus_for_each_dev+0xf4/0x178
>  driver_attach+0x3c/0x58
>  bus_add_driver+0x234/0x4d4
>  driver_register+0xf4/0x3c0
>  __platform_driver_register+0x60/0x88
>  scmi_driver_init+0xb0/0x104
>  do_one_initcall+0xb4/0x664
>  kernel_init_freeable+0x3c8/0x894
>  kernel_init+0x24/0x1e8
>  ret_from_fork+0x10/0x20
> 
> Allocated by task 1:
>  kasan_save_stack+0x2c/0x54
>  kasan_set_track+0x2c/0x40
>  kasan_save_alloc_info+0x24/0x34
>  __kasan_kmalloc+0xa0/0xb8
>  __kmalloc_node_track_caller+0x6c/0x104
>  kstrdup+0x48/0x84
>  kstrdup_const+0x34/0x40
>  __scmi_device_create.part.0+0x8c/0x408
>  scmi_device_create+0x104/0x370
>  scmi_chan_setup+0x2a0/0x750
>  scmi_probe+0x7fc/0x1508
>  platform_probe+0xc4/0x19c
>  really_probe+0x32c/0x99c
>  __driver_probe_device+0x15c/0x3c4
>  driver_probe_device+0x5c/0x170
>  __driver_attach+0x1c8/0x440
>  bus_for_each_dev+0xf4/0x178
>  driver_attach+0x3c/0x58
>  bus_add_driver+0x234/0x4d4
>  driver_register+0xf4/0x3c0
>  __platform_driver_register+0x60/0x88
>  scmi_driver_init+0xb0/0x104
>  do_one_initcall+0xb4/0x664
>  kernel_init_freeable+0x3c8/0x894
>  kernel_init+0x24/0x1e8
>  ret_from_fork+0x10/0x20
> 
> Freed by task 1:
>  kasan_save_stack+0x2c/0x54
>  kasan_set_track+0x2c/0x40
>  kasan_save_free_info+0x38/0x5c
>  __kasan_slab_free+0xe8/0x164
>  __kmem_cache_free+0x11c/0x230
>  kfree+0x70/0x130
>  kfree_const+0x20/0x40
>  __scmi_device_destroy+0x70/0x280
>  scmi_device_destroy+0x94/0xd0
>  scmi_chan_setup+0x524/0x750
>  scmi_probe+0x7fc/0x1508
>  platform_probe+0xc4/0x19c
>  really_probe+0x32c/0x99c
>  __driver_probe_device+0x15c/0x3c4
>  driver_probe_device+0x5c/0x170
>  __driver_attach+0x1c8/0x440
>  bus_for_each_dev+0xf4/0x178
>  driver_attach+0x3c/0x58
>  bus_add_driver+0x234/0x4d4
>  driver_register+0xf4/0x3c0
>  __platform_driver_register+0x60/0x88
>  scmi_driver_init+0xb0/0x104
>  do_one_initcall+0xb4/0x664
>  kernel_init_freeable+0x3c8/0x894
>  kernel_init+0x24/0x1e8
>  ret_from_fork+0x10/0x20
> 
> Fixes: ee7a9c9f67c5 ("firmware: arm_scmi: Add support for multiple device per protocol")
> Signed-off-by: Xinqi Zhang <quic_xinqzhan@quicinc.com>

Reviewed-by: Bjorn Andersson <andersson@kernel.org>

Regards,
Bjorn

> ---
> Changes in v2:
> - Standardize commit messages and add Fixes tags.
> - Link to v1: https://lore.kernel.org/r/20241015-fix-arm-scmi-slab-use-after-free-v1-1-b006eba9c8df@quicinc.com
> ---
>  drivers/firmware/arm_scmi/bus.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
> index 96b2e5f9a8ef0386525f9d91d2925e7e6d48ac28..157172a5f2b577ce4f04425f967f548230c1ebed 100644
> --- a/drivers/firmware/arm_scmi/bus.c
> +++ b/drivers/firmware/arm_scmi/bus.c
> @@ -325,7 +325,10 @@ EXPORT_SYMBOL_GPL(scmi_driver_unregister);
>  
>  static void scmi_device_release(struct device *dev)
>  {
> -	kfree(to_scmi_dev(dev));
> +	struct scmi_device *scmi_dev = to_scmi_dev(dev);
> +
> +	kfree_const(scmi_dev->name);
> +	kfree(scmi_dev);
>  }
>  
>  static void __scmi_device_destroy(struct scmi_device *scmi_dev)
> @@ -338,7 +341,6 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev)
>  	if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
>  		atomic_set(&scmi_syspower_registered, 0);
>  
> -	kfree_const(scmi_dev->name);
>  	ida_free(&scmi_bus_id, scmi_dev->id);
>  	device_unregister(&scmi_dev->dev);
>  }
> @@ -410,7 +412,6 @@ __scmi_device_create(struct device_node *np, struct device *parent,
>  
>  	return scmi_dev;
>  put_dev:
> -	kfree_const(scmi_dev->name);
>  	put_device(&scmi_dev->dev);
>  	ida_free(&scmi_bus_id, id);
>  	return NULL;
> 
> ---
> base-commit: eca631b8fe808748d7585059c4307005ca5c5820
> change-id: 20241015-fix-arm-scmi-slab-use-after-free-74e358b3c90c
> 
> Best regards,
> -- 
> Xinqi Zhang <quic_xinqzhan@quicinc.com>
> 
>