From nobody Sat Sep 26 22:58:21 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) (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 E8C903BE146; Fri, 28 Aug 2026 10:31:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787913113; cv=none; b=WiAGHwdfe6JygUXS2QsvN3KG0MwPydQlUavt5RYuZwAA+QGF7IsrzqoZeoa0GkZcKkw+FVew9hnJnsT4ZtS8+fhaHq1Zc/DO7cEcGo6tiFkv8QgjaTur3v3kQbdT1ePfopfbfJlXRnT+S1wHPL77q212MFIHjv/NemPJ83ma9Fw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787913113; c=relaxed/simple; bh=tycX6rDGVDnqUzXGzft8UrFrEKQ7OK0AvtUifPdMAF0=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=kjhQ4cHMvIY9fu6Sb6HzbZTyfLDjclwRY8Ez+/9rzKAaNIbKAZF3uvxOIdVplXG44ys1cmWbNEX9Ik5MkwThP7N2i/NjZiKm89aJlI1Wyp2FtahiD9Iq0sVCbygy4RvOFFMnfDxV9z47AsgAxVkrqycNMdNJcragFBrvUJOY1Kk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=ctmxte7V; arc=none smtp.client-ip=220.197.31.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="ctmxte7V" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=I4 N8gzh34TI4s9xtonIahAOEOyG3JFBd/5w0IEWxzdw=; b=ctmxte7VTqPZfHLDUH qSPlOfreNlz3vxDreQ9CQ7w4dognsWsVp83ezPsYhkSNh4aF3tvtRLKwfkaLP37t +LvNB1+AjJRcyctC4dkIQrHrkWNAMhJ30eyhcgs58+GBAaHN2pSbM9DSX7ZdT89C 53RzD6hQpvLn+zhaQPjjvQhSM= Received: from localhost.localdomain (unknown []) by gzsmtp4 (Coremail) with SMTP id PygvCgAnfhtxY5FqOxmtOg--.5497S2; Fri, 28 Aug 2026 18:31:13 +0800 (CST) From: oushixiong1025@163.com To: Chunfeng Yun Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, Shixiong Ou Subject: [PATCH] usb: mtu3: fix double dereference in mtu3_log_ep trace event Date: Fri, 28 Aug 2026 18:31:10 +0800 Message-Id: <20260828103110.893817-1-oushixiong1025@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: PygvCgAnfhtxY5FqOxmtOg--.5497S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxJw15CFyxXr1kWFW5Wr4Durg_yoW5Gr1fpa yfuF9rKF4ktwsFvF4kZ34FyFZ0vrWFvFyrKryxu3s5Z3WS9FnxtFs7tryF9ryqkrWrCFy7 JF1qkryrX3Wj937anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UKXd8UUUUU= X-CM-SenderInfo: xrxvxxx0lr0wirqskqqrwthudrp/xtbC-hHzA2qRY3FYVQAA37 Content-Type: text/plain; charset="utf-8" From: Shixiong Ou TP_printk() dereferences the gpd_ring pointer stored in the entry via &__entry->gpd_ring->dma, which may point to freed memory when the trace record is read later. Store the dma address in the entry and print that instead. This is detected at boot: TRACE EVENT ERROR: Event mtu3_gadget_ep_set_halt has double dereference i= n TP_printk: &REC->gpd_ring->dma ------------[ cut here ]------------ Event mtu3_gadget_ep_set_halt has double dereference in TP_printk: &REC->= gpd_ring->dma WARNING: kernel/trace/trace_events.c:420 at test_double_dereference+0x138= /0x140, CPU#0: swapper/0/0 Call trace: test_double_dereference+0x138/0x140 (P) trace_event_raw_init+0x350/0x5b8 event_init+0x38/0xb0 trace_event_init+0xf4/0x5c8 trace_init+0x30/0x6b8 start_kernel+0x4a4/0x8d8 __primary_switched+0x88/0x98 TRACE EVENT ERROR: Event mtu3_gadget_ep_disable has double dereference in= TP_printk: &REC->gpd_ring->dma TRACE EVENT ERROR: Event mtu3_gadget_ep_enable has double dereference in = TP_printk: &REC->gpd_ring->dma Fixes: 83374e035b62 ("usb: mtu3: add tracepoints to help debug") Signed-off-by: Shixiong Ou --- drivers/usb/mtu3/mtu3_trace.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/mtu3/mtu3_trace.h b/drivers/usb/mtu3/mtu3_trace.h index 89870175d635..041e730c88a6 100644 --- a/drivers/usb/mtu3/mtu3_trace.h +++ b/drivers/usb/mtu3/mtu3_trace.h @@ -224,6 +224,7 @@ DECLARE_EVENT_CLASS(mtu3_log_ep, __field(unsigned int, flags) __field(unsigned int, direction) __field(struct mtu3_gpd_ring *, gpd_ring) + __field(dma_addr_t, gpd_dma) ), TP_fast_assign( __assign_str(name); @@ -235,12 +236,13 @@ DECLARE_EVENT_CLASS(mtu3_log_ep, __entry->flags =3D mep->flags; __entry->direction =3D mep->is_in; __entry->gpd_ring =3D &mep->gpd_ring; + __entry->gpd_dma =3D mep->gpd_ring.dma; ), TP_printk("%s: type %s maxp %d slot %d mult %d burst %d ring %p/%pad flag= s %c:%c%c%c:%c", __get_str(name), usb_ep_type_string(__entry->type), __entry->maxp, __entry->slot, __entry->mult, __entry->maxburst, - __entry->gpd_ring, &__entry->gpd_ring->dma, + __entry->gpd_ring, &__entry->gpd_dma, __entry->flags & MTU3_EP_ENABLED ? 'E' : 'e', __entry->flags & MTU3_EP_STALL ? 'S' : 's', __entry->flags & MTU3_EP_WEDGE ? 'W' : 'w', --=20 2.25.1 No virus found Checked by Hillstone Network AntiVirus