[PATCH v1] counter: fix NULL pointer dereference on counter_comp_u8_store()

From: Oleksij Rempel
Date: Thu Feb 03 2022 - 09:03:12 EST


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>
---
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