From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 536AF480968 for ; Tue, 14 Jul 2026 14:54:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784040894; cv=none; b=Yuwf9v1tXO6hKiugNdJPOh+SbwPx0AO7g2ZVEGsIWCf/wURDIB2eVChIsCqP9DxzEOMHGtN9kV1Wa5Dn20BpCftTA4ZCO/GumRhyZJg+14oZpqIR/nt66sjfaH78jw7mrFZHSzh8EJgC1QGoGzk9sxgVvro6UJTC4yhBHAMOcqY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784040894; c=relaxed/simple; bh=MvofQzrsbJtJmlwyY5gJB+PEmE/XPVrnWIbOjUSkjhg=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=ORLYalghauQ8ioqU41glaE5ZQDq6YX3M5H63hr8QzEgxyPckWcxpqr27zKqM/wUGw1HLE/Zr5KMYAjyikYqaJu+/IyS2gsMgG0DTbqysLU/0dghYyHTc3pXzbf5JgXObgm9YaYMH5g8wqFCDdjvU2wv5Las74oBUoCYSNGZPlos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TnKQwCjA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TnKQwCjA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B83A61F000E9; Tue, 14 Jul 2026 14:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784040893; bh=nQBbSLbW+NXSRTwtnkhi6tvjgH+s/vxR2x9I+XCX4bk=; h=Subject:To:Cc:From:Date; b=TnKQwCjAIYOyoagPV9lEd0+hS9CbZHvjkrihuLP8Eqff7f1RdIHMQiJXzeum8y4sM K0Ft5U+5aV3SjPPe7THvR7YYyTjaK3iQGcL6OMbas56Jn/RHYBt4IvqiqyFwh3EUvX u9FR0g2BkmrQ+ZwWlwNf2dmsDQvRVnj2udSIfTu0= Subject: FAILED: patch "[PATCH] HID: appleir: fix UAF on pending key_up_timer in remove()" failed to apply to 5.10-stable tree To: maskmemanish@gmail.com,jkosina@suse.com Cc: From: Date: Tue, 14 Jul 2026 16:54:31 +0200 Message-ID: <2026071431-undefined-extenuate-7534@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 75fe87e19d8aff81eb2c64d15d244ab8da4de945 # git commit -s git send-email --to '' --in-reply-to '2026071431-undefined-extenuate-7534@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 75fe87e19d8aff81eb2c64d15d244ab8da4de945 Mon Sep 17 00:00:00 2001 From: Manish Khadka Date: Fri, 15 May 2026 23:17:52 +0545 Subject: [PATCH] HID: appleir: fix UAF on pending key_up_timer in remove() appleir_remove() runs hid_hw_stop() before timer_delete_sync(). hid_hw_stop() synchronously unregisters the HID input device via hid_disconnect() -> hidinput_disconnect() -> input_unregister_device(), which drops the last reference and frees the underlying input_dev when no userspace handle holds it open. key_up_tick() reads appleir->input_dev and calls input_report_key() / input_sync() on it. The timer is armed from appleir_raw_event() with a HZ/8 (~125 ms) timeout on every keydown and key-repeat report. If a key was pressed shortly before the device is disconnected, the timer can fire after hid_hw_stop() has freed input_dev but before the teardown drains it. A simple reorder is not sufficient. Putting the timer drain first still leaves a window where a USB URB completion (raw_event) running during hid_hw_stop() can call mod_timer() and re-arm the timer, which then fires after hidinput_disconnect() has freed input_dev. The same URB-completion window also lets raw_event() reach key_up(), key_down() and battery_flat() directly, all of which dereference appleir->input_dev. Introduce a 'removing' flag on struct appleir, gated by the existing spinlock. appleir_remove() sets the flag under the lock and then shuts down the timer with timer_shutdown_sync(), which both drains any in-flight callback and permanently disables further mod_timer() calls. appleir_raw_event() and key_up_tick() bail out early if the flag is set, so no path can arm or run the timer, or dereference appleir->input_dev, after remove() has started tearing down. The keyrepeat and flatbattery branches of appleir_raw_event() previously called into the input layer without holding the spinlock; take it now so the flag check is well-defined. This incidentally closes a pre-existing read-side race on appleir->current_key in the keyrepeat branch. This bug is structurally a sibling of commit 4db2af929279 ("HID: appletb-kbd: fix UAF in inactivity-timer cleanup path") and has been present since the driver was introduced. Fixes: 9a4a5574ce42 ("HID: appleir: add support for Apple ir devices") Cc: stable@vger.kernel.org Signed-off-by: Manish Khadka Signed-off-by: Jiri Kosina diff --git a/drivers/hid/hid-appleir.c b/drivers/hid/hid-appleir.c index 5e8ced7bc05a..adaa44a858ed 100644 --- a/drivers/hid/hid-appleir.c +++ b/drivers/hid/hid-appleir.c @@ -109,9 +109,10 @@ struct appleir { struct hid_device *hid; unsigned short keymap[ARRAY_SIZE(appleir_key_table)]; struct timer_list key_up_timer; /* timer for key up */ - spinlock_t lock; /* protects .current_key */ + spinlock_t lock; /* protects .current_key, .removing */ int current_key; /* the currently pressed key */ int prev_key_idx; /* key index in a 2 packets message */ + bool removing; /* set during teardown; gates input_dev access */ }; static int get_key(int data) @@ -172,7 +173,7 @@ static void key_up_tick(struct timer_list *t) unsigned long flags; spin_lock_irqsave(&appleir->lock, flags); - if (appleir->current_key) { + if (!appleir->removing && appleir->current_key) { key_up(hid, appleir, appleir->current_key); appleir->current_key = 0; } @@ -195,6 +196,10 @@ static int appleir_raw_event(struct hid_device *hid, struct hid_report *report, int index; spin_lock_irqsave(&appleir->lock, flags); + if (appleir->removing) { + spin_unlock_irqrestore(&appleir->lock, flags); + goto out; + } /* * If we already have a key down, take it up before marking * this one down @@ -229,17 +234,25 @@ static int appleir_raw_event(struct hid_device *hid, struct hid_report *report, appleir->prev_key_idx = 0; if (!memcmp(data, keyrepeat, sizeof(keyrepeat))) { - key_down(hid, appleir, appleir->current_key); - /* - * Remote doesn't do key up, either pull them up, in the test - * above, or here set a timer which pulls them up after 1/8 s - */ - mod_timer(&appleir->key_up_timer, jiffies + HZ / 8); + spin_lock_irqsave(&appleir->lock, flags); + if (!appleir->removing) { + key_down(hid, appleir, appleir->current_key); + /* + * Remote doesn't do key up, either pull them up, in + * the test above, or here set a timer which pulls them + * up after 1/8 s + */ + mod_timer(&appleir->key_up_timer, jiffies + HZ / 8); + } + spin_unlock_irqrestore(&appleir->lock, flags); goto out; } if (!memcmp(data, flatbattery, sizeof(flatbattery))) { - battery_flat(appleir); + spin_lock_irqsave(&appleir->lock, flags); + if (!appleir->removing) + battery_flat(appleir); + spin_unlock_irqrestore(&appleir->lock, flags); /* Fall through */ } @@ -318,8 +331,20 @@ static int appleir_probe(struct hid_device *hid, const struct hid_device_id *id) static void appleir_remove(struct hid_device *hid) { struct appleir *appleir = hid_get_drvdata(hid); + unsigned long flags; + + /* + * Mark the driver as tearing down so that any concurrent raw_event + * (e.g. from a USB URB completion that hid_hw_stop() has not yet + * killed) and the key_up_timer softirq stop touching input_dev + * before hid_hw_stop() frees it via hidinput_disconnect(). + */ + spin_lock_irqsave(&appleir->lock, flags); + appleir->removing = true; + spin_unlock_irqrestore(&appleir->lock, flags); + + timer_shutdown_sync(&appleir->key_up_timer); hid_hw_stop(hid); - timer_delete_sync(&appleir->key_up_timer); } static const struct hid_device_id appleir_devices[] = {