From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794590251; b=fVvgWs0X/jj41eNb+yScdl0mn2Cd1ZPm4NTEL7x25tI0Bt0r9DDMkXVKzfm5cDuHkt35 nIKJ6vBkrQHefoR1qR0BE+NBArIXRQdorZsGpAd6rFq4JIXsOtfU++/YyOIBBZqsZmglp y2KFCRJjvv3qtofvk8Jj2sbl6Ui2w+DFvIEq2tIOusRwoH8rLwN20TBTufatDGjGiFhTm YGGclA7+nbNF0UP/V+U9FgQ8ogAldbIzEd7gAuX4xGIY94yfdhX+7BBNAEJvCFW8WlrB3 sPPtN0SOjDHta9L5T2KgxlP9Gh2dAKRGKxeR7zLFPa3NPN1ue4ljwFfEYou25tvFdVA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590251; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=m7IZqHGynimGLpY25LT9vDhmTu25e1wiRh0jMM8XB0Y=; b=tusWW8/0Tvzby1OjQn7BTkescdkZyodzLtxEQFb3XsW9BHGRgPaL5z59tiEKjPwXxXxt Tb0Oxip0gbAdtVZjsLvYICtEj3/Sb1pPJMDdCTY40X2eHzJI7iuTY7HqLlYBBjWxV9p7b 5IxY244afEQQYIDB6k3dssj+KktXiovRAD+At0xIuzHKmZzvR9vL9KVO5k6tmxSwkmfnC z+F0gCCwOj70p9qWG/vR/pz2xrhZLCpf44PeiVibCxHzFp8C1+JLhGS0p451gqQz/U8sL yPJ7GS+st/mYwO23S8I6B/Yjcvqjt6XAavhc+6KbsV/EEniL727jdrINlU/wp0ZBsKw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=lcX38Hyw; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CEA8360A263D; Fri, 13 Nov 2026 17:17:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=lcX38Hyw Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B8CA1F000C4; Fri, 13 Nov 2026 17:17:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590251; bh=m7IZqHGynimGLpY25LT9vDhmTu25e1wiRh0jMM8XB0Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lcX38HywCSex9YVsvSdYOTfCIKU7wGHVUQKtJBGqA8zVymzaVRuP49aR3TpSSXpqm ugOUspkIcH2xGZTVtdIBBeXRMjZbJ61dY94PLk7isNDB8y4mU1R+ikwfuNx2Qce0iE gJ/pcpG2QPAH9cdmIPLO5iRte+3Pvk31e+SBm+2s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bin Yu , Cheng Wen , YuanZhe Liu <25031212351@stu.xidian.edu.cn>, Takashi Iwai , Sasha Levin Subject: [PATCH 6.18 230/686] ALSA: us122l: Fix NULL dereference at hwdep open and release Date: Fri, 13 Nov 2026 10:46:03 -0500 Message-ID: <20261113153828.844400176@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: YuanZhe Liu <25031212351@stu.xidian.edu.cn> [ Upstream commit 820e0050866942b5498488496462d12c6ce1c7a9 ] usb_stream_hwdep_open() and usb_stream_hwdep_release() pass the result of usb_ifnum_to_if() straight to usb_autopm_get_interface() and usb_autopm_put_interface(), without checking it for NULL. usb_ifnum_to_if() returns NULL once the device is gone, since usb_disable_device() clears udev->actconfig on disconnect. The hwdep file can outlive the disconnect: the card is released with snd_card_free_when_closed(), so a process that keeps the character device open reaches the driver's release callback after the USB configuration has been dropped, and interface_to_usbdev() then dereferences the NULL interface at offsetof(struct device, parent). The open callback has the same problem when it races with the disconnect. Check both lookups and fail the open with -ENODEV; in release, skip the runtime PM put when the interface is already gone and still run the rest of the per-file cleanup. Move the us122l->first bookkeeping after the checks so that a failed open no longer leaves a stale file pointer behind. Fixes: 030a07e44129 ("ALSA: Add USB US122L driver") Cc: stable@vger.kernel.org Co-developed-by: Bin Yu Signed-off-by: Bin Yu Co-developed-by: Cheng Wen Signed-off-by: Cheng Wen Signed-off-by: YuanZhe Liu <25031212351@stu.xidian.edu.cn> Link: https://patch.msgid.link/20261028074143.14440-1-25031212351@stu.xidian.edu.cn Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/usb/usx2y/us122l.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/sound/usb/usx2y/us122l.c b/sound/usb/usx2y/us122l.c index 50975b7ef1b8b..46dbf9ea1fb70 100644 --- a/sound/usb/usx2y/us122l.c +++ b/sound/usb/usx2y/us122l.c @@ -129,19 +129,26 @@ static const struct vm_operations_struct usb_stream_hwdep_vm_ops = { static int usb_stream_hwdep_open(struct snd_hwdep *hw, struct file *file) { struct us122l *us122l = hw->private_data; - struct usb_interface *iface; + struct usb_interface *iface, *iface0 = NULL; if (hw->used >= 2) return -EBUSY; - if (!us122l->first) - us122l->first = file; - if (us122l->is_us144) { - iface = usb_ifnum_to_if(us122l->dev, 0); - usb_autopm_get_interface(iface); + iface0 = usb_ifnum_to_if(us122l->dev, 0); + if (!iface0) + return -ENODEV; } + iface = usb_ifnum_to_if(us122l->dev, 1); + if (!iface) + return -ENODEV; + + if (!us122l->first) + us122l->first = file; + + if (iface0) + usb_autopm_get_interface(iface0); usb_autopm_get_interface(iface); return 0; } @@ -153,10 +160,12 @@ static int usb_stream_hwdep_release(struct snd_hwdep *hw, struct file *file) if (us122l->is_us144) { iface = usb_ifnum_to_if(us122l->dev, 0); - usb_autopm_put_interface(iface); + if (iface) + usb_autopm_put_interface(iface); } iface = usb_ifnum_to_if(us122l->dev, 1); - usb_autopm_put_interface(iface); + if (iface) + usb_autopm_put_interface(iface); if (us122l->first == file) us122l->first = NULL; guard(mutex)(&us122l->mutex); -- 2.53.0