* [PATCH] [v2] clk: fix slab-use-after-free when clk_core_populate_parent_map failed
@ 2025-10-02 6:12 Yun Zhou
2025-10-16 1:25 ` Zhou, Yun
0 siblings, 1 reply; 4+ messages in thread
From: Yun Zhou @ 2025-10-02 6:12 UTC (permalink / raw)
To: bmasney, mturquette, sboyd, dianders, yun.zhou; +Cc: linux-clk, linux-kernel
If clk_core_populate_parent_map() fails, core->parents will be immediately
released within clk_core_populate_parent_map(). Therefore it is can't be
released in __clk_release() again.
This fixes the following KASAN reported issue:
==================================================================
BUG: KASAN: slab-use-after-free in __clk_release+0x80/0x160
Read of size 8 at addr ffffff8043fd0980 by task kworker/u6:0/27
CPU: 1 PID: 27 Comm: kworker/u6:0 Tainted: G W 6.6.69-yocto-standard+ #7
Hardware name: Raspberry Pi 4 Model B (DT)
Workqueue: events_unbound deferred_probe_work_func
Call trace:
dump_backtrace+0x98/0xf8
show_stack+0x20/0x38
dump_stack_lvl+0x48/0x60
print_report+0xf8/0x5d8
kasan_report+0xb4/0x100
__asan_load8+0x9c/0xc0
__clk_release+0x80/0x160
__clk_register+0x6dc/0xfb8
devm_clk_hw_register+0x70/0x108
bcm2835_register_clock+0x284/0x358
bcm2835_clk_probe+0x2c4/0x438
platform_probe+0x98/0x110
really_probe+0x1e4/0x3e8
__driver_probe_device+0xc0/0x1a0
driver_probe_device+0x110/0x1e8
__device_attach_driver+0xf0/0x1a8
bus_for_each_drv+0xf8/0x178
__device_attach+0x120/0x240
device_initial_probe+0x1c/0x30
bus_probe_device+0xdc/0xe8
deferred_probe_work_func+0xe8/0x130
process_one_work+0x2a4/0x698
worker_thread+0x53c/0x708
kthread+0x1b4/0x1c8
ret_from_fork+0x10/0x20
Allocated by task 27:
kasan_save_stack+0x3c/0x68
kasan_set_track+0x2c/0x40
kasan_save_alloc_info+0x24/0x38
__kasan_kmalloc+0xd4/0xd8
__kmalloc+0x74/0x238
__clk_register+0x718/0xfb8
devm_clk_hw_register+0x70/0x108
bcm2835_register_clock+0x284/0x358
bcm2835_clk_probe+0x2c4/0x438
platform_probe+0x98/0x110
really_probe+0x1e4/0x3e8
__driver_probe_device+0xc0/0x1a0
driver_probe_device+0x110/0x1e8
__device_attach_driver+0xf0/0x1a8
bus_for_each_drv+0xf8/0x178
__device_attach+0x120/0x240
device_initial_probe+0x1c/0x30
bus_probe_device+0xdc/0xe8
deferred_probe_work_func+0xe8/0x130
process_one_work+0x2a4/0x698
worker_thread+0x53c/0x708
kthread+0x1b4/0x1c8
ret_from_fork+0x10/0x20
Freed by task 27:
kasan_save_stack+0x3c/0x68
kasan_set_track+0x2c/0x40
kasan_save_free_info+0x38/0x60
__kasan_slab_free+0x100/0x170
slab_free_freelist_hook+0xcc/0x218
__kmem_cache_free+0x158/0x210
kfree+0x88/0x140
__clk_register+0x9d0/0xfb8
devm_clk_hw_register+0x70/0x108
bcm2835_register_clock+0x284/0x358
bcm2835_clk_probe+0x2c4/0x438
platform_probe+0x98/0x110
really_probe+0x1e4/0x3e8
__driver_probe_device+0xc0/0x1a0
driver_probe_device+0x110/0x1e8
__device_attach_driver+0xf0/0x1a8
bus_for_each_drv+0xf8/0x178
__device_attach+0x120/0x240
device_initial_probe+0x1c/0x30
bus_probe_device+0xdc/0xe8
deferred_probe_work_func+0xe8/0x130
process_one_work+0x2a4/0x698
worker_thread+0x53c/0x708
kthread+0x1b4/0x1c8
ret_from_fork+0x10/0x20
The buggy address belongs to the object at ffffff8043fd0800
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 384 bytes inside of
freed 512-byte region [ffffff8043fd0800, ffffff8043fd0a00)
The buggy address belongs to the physical page:
page:fffffffe010ff400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffffff8043fd0e00 pfn:0x43fd0
head:fffffffe010ff400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4000000000000840(slab|head|zone=1)
page_type: 0xffffffff()
raw: 4000000000000840 ffffff8040002f40 ffffff8040000a50 ffffff8040000a50
raw: ffffff8043fd0e00 0000000000150002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffffff8043fd0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffffff8043fd0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffffff8043fd0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffffff8043fd0a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffffff8043fd0a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Fixes: fc0c209c147f ("clk: Allow parents to be specified without string names")
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
---
drivers/clk/clk.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index b821b2cdb155..b93f38de4cac 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4254,7 +4254,6 @@ static int clk_core_populate_parent_map(struct clk_core *core,
* having a cache of names/clk_hw pointers to clk_core pointers.
*/
parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
- core->parents = parents;
if (!parents)
return -ENOMEM;
@@ -4295,6 +4294,8 @@ static int clk_core_populate_parent_map(struct clk_core *core,
}
}
+ core->parents = parents;
+
return 0;
}
@@ -4302,7 +4303,7 @@ static void clk_core_free_parent_map(struct clk_core *core)
{
int i = core->num_parents;
- if (!core->num_parents)
+ if (!core->parents)
return;
while (--i >= 0) {
--
2.27.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] [v2] clk: fix slab-use-after-free when clk_core_populate_parent_map failed
2025-10-02 6:12 [PATCH] [v2] clk: fix slab-use-after-free when clk_core_populate_parent_map failed Yun Zhou
@ 2025-10-16 1:25 ` Zhou, Yun
2025-10-16 19:33 ` Brian Masney
0 siblings, 1 reply; 4+ messages in thread
From: Zhou, Yun @ 2025-10-16 1:25 UTC (permalink / raw)
To: bmasney, mturquette, sboyd, dianders; +Cc: linux-clk, linux-kernel
Hi Brian,
Can you help me check if there are any issues with this new patch?
Thanks,
Yun
On 10/2/25 14:12, Yun Zhou wrote:
> If clk_core_populate_parent_map() fails, core->parents will be immediately
> released within clk_core_populate_parent_map(). Therefore it is can't be
> released in __clk_release() again.
>
> This fixes the following KASAN reported issue:
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in __clk_release+0x80/0x160
> Read of size 8 at addr ffffff8043fd0980 by task kworker/u6:0/27
>
> CPU: 1 PID: 27 Comm: kworker/u6:0 Tainted: G W 6.6.69-yocto-standard+ #7
> Hardware name: Raspberry Pi 4 Model B (DT)
> Workqueue: events_unbound deferred_probe_work_func
> Call trace:
> dump_backtrace+0x98/0xf8
> show_stack+0x20/0x38
> dump_stack_lvl+0x48/0x60
> print_report+0xf8/0x5d8
> kasan_report+0xb4/0x100
> __asan_load8+0x9c/0xc0
> __clk_release+0x80/0x160
> __clk_register+0x6dc/0xfb8
> devm_clk_hw_register+0x70/0x108
> bcm2835_register_clock+0x284/0x358
> bcm2835_clk_probe+0x2c4/0x438
> platform_probe+0x98/0x110
> really_probe+0x1e4/0x3e8
> __driver_probe_device+0xc0/0x1a0
> driver_probe_device+0x110/0x1e8
> __device_attach_driver+0xf0/0x1a8
> bus_for_each_drv+0xf8/0x178
> __device_attach+0x120/0x240
> device_initial_probe+0x1c/0x30
> bus_probe_device+0xdc/0xe8
> deferred_probe_work_func+0xe8/0x130
> process_one_work+0x2a4/0x698
> worker_thread+0x53c/0x708
> kthread+0x1b4/0x1c8
> ret_from_fork+0x10/0x20
>
> Allocated by task 27:
> kasan_save_stack+0x3c/0x68
> kasan_set_track+0x2c/0x40
> kasan_save_alloc_info+0x24/0x38
> __kasan_kmalloc+0xd4/0xd8
> __kmalloc+0x74/0x238
> __clk_register+0x718/0xfb8
> devm_clk_hw_register+0x70/0x108
> bcm2835_register_clock+0x284/0x358
> bcm2835_clk_probe+0x2c4/0x438
> platform_probe+0x98/0x110
> really_probe+0x1e4/0x3e8
> __driver_probe_device+0xc0/0x1a0
> driver_probe_device+0x110/0x1e8
> __device_attach_driver+0xf0/0x1a8
> bus_for_each_drv+0xf8/0x178
> __device_attach+0x120/0x240
> device_initial_probe+0x1c/0x30
> bus_probe_device+0xdc/0xe8
> deferred_probe_work_func+0xe8/0x130
> process_one_work+0x2a4/0x698
> worker_thread+0x53c/0x708
> kthread+0x1b4/0x1c8
> ret_from_fork+0x10/0x20
>
> Freed by task 27:
> kasan_save_stack+0x3c/0x68
> kasan_set_track+0x2c/0x40
> kasan_save_free_info+0x38/0x60
> __kasan_slab_free+0x100/0x170
> slab_free_freelist_hook+0xcc/0x218
> __kmem_cache_free+0x158/0x210
> kfree+0x88/0x140
> __clk_register+0x9d0/0xfb8
> devm_clk_hw_register+0x70/0x108
> bcm2835_register_clock+0x284/0x358
> bcm2835_clk_probe+0x2c4/0x438
> platform_probe+0x98/0x110
> really_probe+0x1e4/0x3e8
> __driver_probe_device+0xc0/0x1a0
> driver_probe_device+0x110/0x1e8
> __device_attach_driver+0xf0/0x1a8
> bus_for_each_drv+0xf8/0x178
> __device_attach+0x120/0x240
> device_initial_probe+0x1c/0x30
> bus_probe_device+0xdc/0xe8
> deferred_probe_work_func+0xe8/0x130
> process_one_work+0x2a4/0x698
> worker_thread+0x53c/0x708
> kthread+0x1b4/0x1c8
> ret_from_fork+0x10/0x20
>
> The buggy address belongs to the object at ffffff8043fd0800
> which belongs to the cache kmalloc-512 of size 512
> The buggy address is located 384 bytes inside of
> freed 512-byte region [ffffff8043fd0800, ffffff8043fd0a00)
>
> The buggy address belongs to the physical page:
> page:fffffffe010ff400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffffff8043fd0e00 pfn:0x43fd0
> head:fffffffe010ff400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0x4000000000000840(slab|head|zone=1)
> page_type: 0xffffffff()
> raw: 4000000000000840 ffffff8040002f40 ffffff8040000a50 ffffff8040000a50
> raw: ffffff8043fd0e00 0000000000150002 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffffff8043fd0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffffff8043fd0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffffff8043fd0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffffff8043fd0a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffffff8043fd0a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ==================================================================
>
> Fixes: fc0c209c147f ("clk: Allow parents to be specified without string names")
> Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
> Reviewed-by: Brian Masney <bmasney@redhat.com>
> ---
> drivers/clk/clk.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index b821b2cdb155..b93f38de4cac 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -4254,7 +4254,6 @@ static int clk_core_populate_parent_map(struct clk_core *core,
> * having a cache of names/clk_hw pointers to clk_core pointers.
> */
> parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
> - core->parents = parents;
> if (!parents)
> return -ENOMEM;
>
> @@ -4295,6 +4294,8 @@ static int clk_core_populate_parent_map(struct clk_core *core,
> }
> }
>
> + core->parents = parents;
> +
> return 0;
> }
>
> @@ -4302,7 +4303,7 @@ static void clk_core_free_parent_map(struct clk_core *core)
> {
> int i = core->num_parents;
>
> - if (!core->num_parents)
> + if (!core->parents)
> return;
>
> while (--i >= 0) {
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] [v2] clk: fix slab-use-after-free when clk_core_populate_parent_map failed
2025-10-16 1:25 ` Zhou, Yun
@ 2025-10-16 19:33 ` Brian Masney
2025-10-29 8:30 ` Zhou, Yun
0 siblings, 1 reply; 4+ messages in thread
From: Brian Masney @ 2025-10-16 19:33 UTC (permalink / raw)
To: Zhou, Yun; +Cc: mturquette, sboyd, dianders, linux-clk, linux-kernel
Hi Yun,
On Thu, Oct 16, 2025 at 09:25:20AM +0800, Zhou, Yun wrote:
> Hi Brian,
>
> Can you help me check if there are any issues with this new patch?
The new patch looks good to me. Ultimately though it's up to Stephen.
Brian
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] [v2] clk: fix slab-use-after-free when clk_core_populate_parent_map failed
2025-10-16 19:33 ` Brian Masney
@ 2025-10-29 8:30 ` Zhou, Yun
0 siblings, 0 replies; 4+ messages in thread
From: Zhou, Yun @ 2025-10-29 8:30 UTC (permalink / raw)
To: sboyd; +Cc: mturquette, dianders, linux-clk, linux-kernel, Brian Masney
Hi Stephen,
Could you please take a moment to help me review the patch?
Thanks,
Yun
On 10/17/25 03:33, Brian Masney wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> Hi Yun,
>
> On Thu, Oct 16, 2025 at 09:25:20AM +0800, Zhou, Yun wrote:
>> Hi Brian,
>>
>> Can you help me check if there are any issues with this new patch?
> The new patch looks good to me. Ultimately though it's up to Stephen.
>
> Brian
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-10-29 8:30 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2025-10-02 6:12 [PATCH] [v2] clk: fix slab-use-after-free when clk_core_populate_parent_map failed Yun Zhou
2025-10-16 1:25 ` Zhou, Yun
2025-10-16 19:33 ` Brian Masney
2025-10-29 8:30 ` Zhou, Yun
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