From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: linux-input@vger.kernel.org
Cc: Karlos Abel <kabel@voidship.net>,
Benjamin Tissoires <bentiss@kernel.org>,
linux-kernel@vger.kernel.org, Jiri Kosina <jikos@kernel.org>
Subject: [PATCH] Input: always accept EV_SYN in input_event()
Date: Sun, 11 Oct 2026 23:12:40 -0700 [thread overview]
Message-ID: <asx50uz6iafsyAd5@google.com> (raw)
Commit 0cd587735205 ("Input: preallocate memory to hold event values")
moved allocation of dev->vals into input_allocate_device(), which caused
input core to accumulate events reported while seeding initial device
state before input_register_device().
However, because EV_SYN is only set in dev->evbit during
input_register_device() (and some drivers also overwrite dev->evbit
directly before registration), any EV_SYN/SYN_REPORT events sent before
registration were dropped by is_event_supported(), leaving those seeded
events stuck in dev->vals until the next SYN_REPORT after registration.
Always accept EV_SYN in input_event() and input_inject_event() without
checking dev->evbit so input_sync() flushes dev->vals as intended.
Reported-by: Karlos Abel <kabel@voidship.net>,
Fixes: 0cd587735205 ("Input: preallocate memory to hold event values")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/input/input.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 76ed9ff40584..fae508d280db 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -452,7 +452,7 @@ void input_handle_event(struct input_dev *dev,
void input_event(struct input_dev *dev,
unsigned int type, unsigned int code, int value)
{
- if (is_event_supported(type, dev->evbit, EV_MAX)) {
+ if (type == EV_SYN || is_event_supported(type, dev->evbit, EV_MAX)) {
guard(spinlock_irqsave)(&dev->event_lock);
input_handle_event(dev, type, code, value);
}
@@ -476,7 +476,7 @@ void input_inject_event(struct input_handle *handle,
struct input_dev *dev = handle->dev;
struct input_handle *grab;
- if (is_event_supported(type, dev->evbit, EV_MAX)) {
+ if (type == EV_SYN || is_event_supported(type, dev->evbit, EV_MAX)) {
guard(spinlock_irqsave)(&dev->event_lock);
guard(rcu)();
--
2.56.0.385.gd3acb90ef8-goog
--
Dmitry
reply other threads:[~2026-10-12 6:12 UTC|newest]
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