On Thu, Feb 03, 2022 at 02:54:18PM +0100, Oleksij Rempel wrote:
> Current kernel will report NULL pointer dereference with following
> back trace:
> interrupt_cnt_enable_write from counter_comp_u8_store+0xc0/0xf4
> counter_comp_u8_store from dev_attr_store+0x24/0x30
> dev_attr_store from sysfs_kf_write+0x48/0x54
> sysfs_kf_write from kernfs_fop_write_iter+0x128/0x1c8
> kernfs_fop_write_iter from vfs_write+0x124/0x1b4
> vfs_write from ksys_write+0x88/0xe0
> ksys_write from sys_write+0x18/0x1c
> sys_write from ret_fast_syscall+0x0/0x1c
>
> Add missing dev_set_drvdata() to fix it.
>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Hi Oleksij,
This dev_set_drvdata() was removed in commit b56346ddbd82 ("counter: Use
container_of instead of drvdata to track counter_device"). It looks like
we overlooked the counter-sysfs.c file when we made that change.
Would you instead replace the dev_get_drvdata() calls in counter-sysfs.c
with respective container_of() calls? Add a Fixes tag referencing commit
b56346ddbd82 as well to your commit message.
Thanks,
William Breathitt Gray
> ---
> drivers/counter/counter-core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
> index 7e0957eea094..1de16d5e9fbc 100644
> --- a/drivers/counter/counter-core.c
> +++ b/drivers/counter/counter-core.c
> @@ -98,6 +98,8 @@ struct counter_device *counter_alloc(size_t sizeof_priv)
> counter = &ch->counter;
> dev = &counter->dev;
>
> + dev_set_drvdata(dev, counter);
> +
> /* Acquire unique ID */
> err = ida_alloc(&counter_ida, GFP_KERNEL);
> if (err < 0)
> --
> 2.30.2
>
Attachment:
signature.asc
Description: PGP signature
