From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Aldo Ariel Panzardo <qwe.aldo@gmail.com>
Cc: jikos@kernel.org, bentiss@kernel.org,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [PATCH v8 2/2] HID: multitouch: fix use-after-free of haptic data on delayed input release
Date: Fri, 16 Oct 2026 11:27:12 -0700 [thread overview]
Message-ID: <atJrRjjgXZz5A-Lq@google.com> (raw)
In-Reply-To: <20261016173056.3397211-3-qwe.aldo@gmail.com>
On Fri, Oct 16, 2026 at 02:30:56PM -0300, Aldo Ariel Panzardo wrote:
> mt_probe() allocates td->haptic with devm_kzalloc() and hid_haptic_init()
> stores it in ff->private. When the HID device is removed while an evdev
> fd is still held, devres frees td->haptic at unbind but
> hid_haptic_destroy() runs later from input_dev_release() and dereferences
> the freed pointer. input_ff_destroy() then double-frees it via
> kfree(ff->private).
Right, so that is the root of the problem. We should not be allocating
memory assigned to ff->private with devm as its lifetime is not directly
tied to the time when device is bound to a driver.
Your initial approach was correct one.
Thanks.
--
Dmitry
prev parent reply other threads:[~2026-10-16 18:27 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20261009103333.2476105-1-qwe.aldo@gmail.com>
2026-10-16 13:55 ` [PATCH v5 0/2] HID: multitouch: fix use-after-free of haptic data on delayed input release Aldo Ariel Panzardo
2026-10-16 13:55 ` [PATCH v5 1/2] HID: haptic: reorder try_module_get/get_device before input_ff_create Aldo Ariel Panzardo
2026-10-16 14:06 ` sashiko-bot
2026-10-16 13:55 ` [PATCH v5 2/2] HID: multitouch: fix use-after-free of haptic data on delayed input release Aldo Ariel Panzardo
2026-10-16 14:12 ` sashiko-bot
2026-10-16 15:13 ` [PATCH v6 0/2] " Aldo Ariel Panzardo
2026-10-16 15:13 ` [PATCH v6 1/2] HID: haptic: reorder try_module_get/get_device before input_ff_create Aldo Ariel Panzardo
2026-10-16 15:35 ` sashiko-bot
2026-10-16 15:13 ` [PATCH v6 2/2] HID: multitouch: fix use-after-free of haptic data on delayed input release Aldo Ariel Panzardo
2026-10-16 16:33 ` [PATCH v7 0/2] " Aldo Ariel Panzardo
2026-10-16 16:33 ` [PATCH v7 1/2] HID: haptic: reorder try_module_get/get_device before input_ff_create Aldo Ariel Panzardo
2026-10-16 16:42 ` sashiko-bot
2026-10-16 18:16 ` Dmitry Torokhov
2026-10-16 16:33 ` [PATCH v7 2/2] HID: multitouch: fix use-after-free of haptic data on delayed input release Aldo Ariel Panzardo
2026-10-16 17:30 ` [PATCH v8 0/2] " Aldo Ariel Panzardo
2026-10-16 17:30 ` [PATCH v8 1/2] HID: haptic: reorder try_module_get/get_device before input_ff_create Aldo Ariel Panzardo
2026-10-16 17:30 ` [PATCH v8 2/2] HID: multitouch: fix use-after-free of haptic data on delayed input release Aldo Ariel Panzardo
2026-10-16 18:27 ` Dmitry Torokhov [this message]
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