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=1794590238; b=pnDVAz2uKq56Z3yrBGPsgIBYlJkUclGDSARqSNK8bD3hbIJahwUtbiGnxhAxD/JUI/fZ FLnjBk0ureeW7Z5Ui1IUXMkriJVjOp2sprrN6jNTcr0UuaRwGqPS3sM5/wIzWu00avD76 LSHnax8ZRXyuDscQKibQ8pq9oi3OrXa14ev5dJnP7H2j81I+SSpItlWpZ8ZoWPENTxGGv 9KZAOI+ywDKp8asd5h7P/2stq37trSOutYmDDwr7oKAdQheU/+4aK3pcYJ2Eb0Ih0315K mlO82ke5aaNT6uIFbEeTdSkCE/JEd2n4Lb66Bk+PjGhk0DtQ2tUd4K0z2x9RmHOnuaA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590238; 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=vY9TIm/zOdhpTK1bQVKNfwRkTrUygiepos9ehMfGPN0=; b=csbYdAgK+tNSRebB3pLVY/eXpnrSZ/9Fn89mDAlUGcHmbrn1SZK8fRV4TSY2zqMdqRWv OJAL+mLac5EaueXmT8tcJGFNFa3KfBwwdIBvjD9Ul6gi6AYe5BuDrSzofUY0QbEL3dnE4 sFh1yhjIeHTzdy9KGzrA0+ED30E7Zy+4AkaRGF5fyWc4kZ4wBV/U0k15YkrFyTi+ou+2N 8m6l66fjktrmNqRXYIZi93hy2Cqh18BW0NByW0WaDJSBisJ9XXDF7zNWbPuQLN8CqfdHd zo3MHIh3TQ8V3dDen/8CLBrvk1gh6qdT3kHeSlqHXPVViQdjlTAGs5F0dEBZyO86u7g== 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=CdRhCQ00; 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 2CE1F6075E26; Fri, 13 Nov 2026 17:17:18 +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=CdRhCQ00 Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC6DC1F000C6; Fri, 13 Nov 2026 17:17:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590238; bh=vY9TIm/zOdhpTK1bQVKNfwRkTrUygiepos9ehMfGPN0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CdRhCQ00gECMoqRahAEhMB42npbqvts6+E5rfLfBSwt+wuCLxHVxv4C9L5cev/UVR 8jmryL0hH4vL1nJ9RcKYIXPex7YgZ986Gm5KzPts7WyyK0mwGOcGbdvF1rcKdc2yrg Xfaj6nfXPfdDFoVTAXty2EC7lNAv6bHU9lC+SIsM= 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 6.18 229/686] ALSA: us122l: Add missing NULL check in usb_stream_hwdep_mmap() Date: Fri, 13 Nov 2026 10:46:02 -0500 Message-ID: <20261113153828.778113968@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 f5d3eb483fed59fc0f3b059b8b6a32cedc922360 ] usb_stream_hwdep_mmap() reads us122l->sk.s and dereferences it without checking for NULL. The stream object is released by usb_stream_free(), which is reached through us122l_stop() both when the device is disconnected and when us122l_start() fails, and it leaves us122l->sk.s set to NULL. The hwdep file stays usable after that, so a later mmap() KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:usb_stream_hwdep_mmap+0x107/0x890 sound/usb/usx2y/us122l.c:182 crashes while reading s->read_size, which sits at offset 0x10. That NULL is an expected state for this field: usb_stream_hwdep_vm_fault(), usb_stream_hwdep_poll(), usb_stream_hwdep_ioctl(), usb_stream_stop() and usb_stream_free() all test it before use. Only the mmap callback misses the check, so let it return -ENODEV, matching what the other hwdep mapping in usx2yhwdeppcm.c does when its shared buffer has not been allocated. Fixes: 030a07e441296c372f946cd4065b5d831d8dc40c ("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/20261028042525.8737-1-25031212351@stu.xidian.edu.cn Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/usb/usx2y/us122l.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/usb/usx2y/us122l.c b/sound/usb/usx2y/us122l.c index aaeae099b5f2e..50975b7ef1b8b 100644 --- a/sound/usb/usx2y/us122l.c +++ b/sound/usb/usx2y/us122l.c @@ -179,6 +179,8 @@ static int usb_stream_hwdep_mmap(struct snd_hwdep *hw, offset = area->vm_pgoff << PAGE_SHIFT; guard(mutex)(&us122l->mutex); s = us122l->sk.s; + if (!s) + return -ENODEV; read = offset < s->read_size; if (read) { if (area->vm_flags & VM_WRITE) -- 2.53.0