From c57016bcf6d0b57cda5579e5d6856bd9bbe52a77 Mon Sep 17 00:00:00 2001 From: Basavaraj Natikar Date: Mon, 3 Aug 2026 23:22:27 +0530 Subject: [PATCH] HID: amd_sfh: Serialize access to the shared emp2 pointer The SFH accessors reach the device through a file-global emp2 pointer that is published at probe and cleared on remove. amd_get_sfh_info() is exported and called from other modules on unrelated threads, so a reader can observe a non-NULL emp2 and then race a concurrent unbind that clears it and frees the device. Serialize the emp2 publish/clear and all readers under a mutex, so a reader either sees a live device for the whole access or sees NULL. Signed-off-by: Basavaraj Natikar Signed-off-by: Jiri Kosina --- drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c index 837d59e7a661..dd2720bae65c 100644 --- a/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c +++ b/drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c @@ -8,12 +8,14 @@ * Author: Basavaraj Natikar */ #include +#include #include #include #include "amd_sfh_interface.h" static struct amd_mp2_dev *emp2; +static DEFINE_MUTEX(emp2_lock); static int amd_sfh_wait_response(struct amd_mp2_dev *mp2, u8 sid, u32 cmd_id) { @@ -78,12 +80,14 @@ static struct amd_mp2_ops amd_sfh_ops = { void sfh_deinit_emp2(void) { + guard(mutex)(&emp2_lock); emp2 = NULL; } void sfh_interface_init(struct amd_mp2_dev *mp2) { mp2->mp2_ops = &amd_sfh_ops; + guard(mutex)(&emp2_lock); emp2 = mp2; } @@ -160,6 +164,8 @@ static int amd_sfh_als_info(u32 *ambient_light) int amd_get_sfh_info(struct amd_sfh_info *sfh_info, enum sfh_message_type op) { + guard(mutex)(&emp2_lock); + if (sfh_info) { switch (op) { case MT_HPD: