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 18E39472F67 for ; Tue, 25 Aug 2026 13:16:24 +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=1787663786; cv=none; b=KqBm7yPVyOqETGzFlsFNzc1fm+JNlm2MNrW9GL+WIYOaGCEzjBHrTzi/4SHUrxQOzZZUYVNGvqzcrQbbB+lMd4DQOZgcGcBvEPKmmgaeRqeROPlpQHPSngkaIrotLuEzSY5h1m0o+zU9QIrlpl6M59I223gzo36b2voUN2ZFCtk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787663786; c=relaxed/simple; bh=3Zv6SBLe8LE9P4b0xt7gwZe3HRhqTcI223JkEElwIG0=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=nQ/oaTXCdjOqQBSv8SVvhYw1GPHzSGGIRg/YCY9JseWHH0SHh1phU1/ptFC73irQ83HYhHWjwAt6CLUls0/bu69xhJ7adxKyVECDJq9g/LW8dOaB901CdB8XgXDRHnJl8rr1jFsJ/02Ru731H+cUGJ82DJYkhaU82M6DdiJ1h3A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nyRF/+YS; 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="nyRF/+YS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 774531F000E9; Tue, 25 Aug 2026 13:16:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787663784; bh=ZB5z4JDqsIsOHHZOFfgI6SsggELYhuZwyFjZevZQImA=; h=Subject:To:Cc:From:Date; b=nyRF/+YS3gMc7xvPfisBYeASJR34Q0fMaSFBfW6vesdbCEXe71f7kNnlkfXrbaUxN JakiuoBcKtsqQZ+mdG+zGBrxj0fMnY7fZqiXl9whsxwqdJTyD9xApNqLhc9pLn5SEl vkEOerppISjBl6P+OEuBpInb3FYt+GyipyO6V1Rk= Subject: FAILED: patch "[PATCH] HID: uclogic: fix use-after-free of inrange_timer on remove" failed to apply to 5.15-stable tree To: security@auditcode.ai,jkosina@suse.com Cc: From: Date: Tue, 25 Aug 2026 15:15:57 +0200 Message-ID: <2026082557-kindling-coping-1767@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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x 506fd50a9027340f0e9dcc587d10ccb03312dba6 # git commit -s git send-email --to '' --in-reply-to '2026082557-kindling-coping-1767@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 506fd50a9027340f0e9dcc587d10ccb03312dba6 Mon Sep 17 00:00:00 2001 From: Ibrahim Hashimov Date: Tue, 14 Jul 2026 19:39:46 +0200 Subject: [PATCH] HID: uclogic: fix use-after-free of inrange_timer on remove uclogic_remove() cancels the pen in-range timer and then stops the device: timer_delete_sync(&drvdata->inrange_timer); hid_hw_stop(hdev); timer_delete_sync() only guarantees the timer is idle at that instant. uclogic_raw_event_pen() keeps delivering pen reports until hid_hw_stop() stops the transport several lines later, and every report with pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE re-arms the timer: mod_timer(&drvdata->inrange_timer, jiffies + msecs_to_jiffies(100)); A report landing between the timer_delete_sync() call and the transport teardown in hid_hw_stop() re-arms inrange_timer after it was cancelled. uclogic_remove() then returns and the devm drvdata is freed, while hid_hw_stop() has already freed the input device drvdata->pen_input points at, so when the timer fires ~100 ms later uclogic_inrange_timeout() dereferences freed memory -- a use-after-free in timer-softirq context. Swapping the two calls is not a fix: stopping the device first frees drvdata->pen_input via hidinput_disconnect() while the timer may still be pending, so a timer already armed before removal fires on the freed input device in the window before timer_delete_sync() runs. Use timer_shutdown_sync() before hid_hw_stop() instead. It cancels the timer, waits for a running callback while pen_input is still valid, and prevents any further re-arming -- a later mod_timer() from an in-flight report is silently ignored -- so the timer is provably dead before hid_hw_stop() frees the inputs. This is the ordering the timer core documents for this "timer re-armed from another path" teardown case. Fixes: 01309e29eb95 ("HID: uclogic: Support in-range reporting emulation") Cc: stable@vger.kernel.org Signed-off-by: Ibrahim Hashimov Assisted-by: AuditCode-AI:2026.07 Signed-off-by: Jiri Kosina diff --git a/drivers/hid/hid-uclogic-core.c b/drivers/hid/hid-uclogic-core.c index b73f09d26688..0b8a83fa6c5b 100644 --- a/drivers/hid/hid-uclogic-core.c +++ b/drivers/hid/hid-uclogic-core.c @@ -548,7 +548,17 @@ static void uclogic_remove(struct hid_device *hdev) { struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev); - timer_delete_sync(&drvdata->inrange_timer); + /* + * Shut the in-range timer down before stopping the device. + * uclogic_raw_event_pen() re-arms inrange_timer on every pen report + * and keeps running until hid_hw_stop() stops the transport, so a + * plain timer_delete_sync() here can be undone by a report landing in + * the window before hid_hw_stop(). timer_shutdown_sync() cancels the + * timer and makes any later re-arm a no-op, so it is provably dead + * before hid_hw_stop() frees the input device drvdata->pen_input + * points at. + */ + timer_shutdown_sync(&drvdata->inrange_timer); hid_hw_stop(hdev); kfree(drvdata->desc_ptr); uclogic_params_cleanup(&drvdata->params);