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 DDA4438E5C5; Thu, 17 Sep 2026 18:16:16 +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=1789668978; cv=none; b=KwfK0JDRUrKZ64/7MgRkfEdTDd/b4pHJQ4xsYygeXZS11a/yQU4ZsCPms4twah7NAk2VfnAoB4hUYS1Mx9KZbG46ra5J/ikmNHtGHdN2yGBXveQFKPs1eq7QTVi2Tvh8e1KTYTgkvEBAH8+V0Qz5i3+2ymHfyiVWnzQhc+FpLwM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789668978; c=relaxed/simple; bh=bHhOK2cod89G6bKpyX29ZIjGRCSh384GRDmKJJXw/zI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X1CnnzI1mlHD4Q5rhmqgbc6CYxR2yINNFgEPjP9nrrwEF/+1LDVEqYDICQ4exyIZZad7DPypBh/MSLBCVQHto+lwMqtY3zh5Dc4NujFmow1NChqWnGvpy/cTh0XSmDn/LUB9vPD2DdBxLWLgvAdIF4IV58Ts089QkKaFBruzvl8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xIygSpml; 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="xIygSpml" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81AB41F00893; Thu, 17 Sep 2026 18:16:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789668976; bh=NHsV2OP4rcUt+iq6va6ghIiXRJdwC7xy1BUmGjCUsHI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=xIygSpmlOxjRk25wPFAeRSshQ1i050RndV4DO5o8WEJq32u9R8qWNawt+mkhJP4p/ yrwTdaX7E9YyCXRD+IaxAbXdPvMpsvznjvM53Isi6Nlkz7Hu38R+y9W1gBp2gBt/ss 9CEjtwgEYdy69ceyOgV44xlXLnC26RxkzdI9oYtQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qingyu Zhang , Takashi Iwai , Sasha Levin Subject: [PATCH 6.12 0604/1102] ALSA: ump: do not touch legacy_rmidi before it exists Date: Thu, 17 Sep 2026 16:09:07 +0100 Message-ID: <20260917151555.178187100@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151539.408551884@linuxfoundation.org> References: <20260917151539.408551884@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qingyu Zhang [ Upstream commit adeee7187694719890aaffdc14b7e89cfd736f1d ] snd_ump_parse_endpoint() sets ump->parsed on every exit, including error, before the caller attaches the legacy rawmidi device. ump_handle_ep_name_msg() then treats parsed as "legacy_rmidi is live" and calls ump_legacy_set_rawmidi_name(), which snprintf()s into ump->legacy_rmidi->name. If a UMP packet arrives in that window (IRQ path from snd_ump_receive), legacy_rmidi is still NULL (KASAN null-ptr-deref in snprintf). Guard the legacy helpers. parsed only means endpoint info was parsed, not that legacy_rmidi exists. Fixes: 37e0e14128e0 ("ALSA: ump: Support UMP Endpoint and Function Block parsing") Signed-off-by: Qingyu Zhang Link: https://patch.msgid.link/20260902073918.880245-1-usupergate@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/ump.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sound/core/ump.c b/sound/core/ump.c index 820a86d4e159d..6542206747a3d 100644 --- a/sound/core/ump.c +++ b/sound/core/ump.c @@ -1316,6 +1316,8 @@ static void update_legacy_names(struct snd_ump_endpoint *ump) { struct snd_rawmidi *rmidi = ump->legacy_rmidi; + if (!rmidi) + return; update_legacy_substreams(ump, rmidi, SNDRV_RAWMIDI_STREAM_INPUT); update_legacy_substreams(ump, rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT); } @@ -1324,6 +1326,8 @@ static void ump_legacy_set_rawmidi_name(struct snd_ump_endpoint *ump) { struct snd_rawmidi *rmidi = ump->legacy_rmidi; + if (!rmidi) + return; snprintf(rmidi->name, sizeof(rmidi->name), "%.68s (MIDI 1.0)", ump->core.name); } -- 2.53.0