From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9DF012727F3; Wed, 8 Apr 2026 18:15:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672131; cv=none; b=MUyh/J48ME2MmXitUUBD5PnBiI6qpDsxKjrv8sBRqR20Ds6taGOhK5I77d3ENEhtGl8yR2jSflXLDD4GpYvmo5bgOfhYVREK272FRKuZKz52EG+i+XfXBW8Ja+h7e6RdlyQyAEW/eYVexrT4gMlgauE3n6X3OHqBgs8M8ez8KRA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672131; c=relaxed/simple; bh=70iZ0Qfh59XvX82e71h9Ikd9JZMvYxMi9HDhgPzIvtw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EPI4pEa+XjuN9mXNaxEmsMIiMmoqfCOw8JkoDAUL64mo/1sjhmqFx8DUc4gfTS3OVi/3TzYFkJmt6gGPf4kMrE0rY2P8hgvYVbRLgg3sljiCQyBG/G51MeannXOZ5Wejn+KMs39wkwNp5a/+g6vglUwPXcitslReSDwgxU00UDw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=h2ZqjVFr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="h2ZqjVFr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36619C19421; Wed, 8 Apr 2026 18:15:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775672131; bh=70iZ0Qfh59XvX82e71h9Ikd9JZMvYxMi9HDhgPzIvtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h2ZqjVFrNVTo5ybQ23l7Avl/d+yqJ54uzwn4taUWdzJzAq6jkBIIrc57FAzhwX6bl B5D129Lek9FzLD0P2KLeL9idiHMcCUW0aQCqPUrvhKbUM+z5wRF7XhKmRlWTlN+wtM uV2K+7sSizL1igY4N/jcs/JWQZzU9Rxzi5n/tc9w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andrey Konovalov , Berk Cem Goksel , Takashi Iwai Subject: [PATCH 6.1 202/312] ALSA: caiaq: fix stack out-of-bounds read in init_card Date: Wed, 8 Apr 2026 20:01:59 +0200 Message-ID: <20260408175941.305457743@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.715315542@linuxfoundation.org> References: <20260408175933.715315542@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Berk Cem Goksel commit 45424e871abf2a152e247a9cff78359f18dd95c0 upstream. The loop creates a whitespace-stripped copy of the card shortname where `len < sizeof(card->id)` is used for the bounds check. Since sizeof(card->id) is 16 and the local id buffer is also 16 bytes, writing 16 non-space characters fills the entire buffer, overwriting the terminating nullbyte. When this non-null-terminated string is later passed to snd_card_set_id() -> copy_valid_id_string(), the function scans forward with `while (*nid && ...)` and reads past the end of the stack buffer, reading the contents of the stack. A USB device with a product name containing many non-ASCII, non-space characters (e.g. multibyte UTF-8) will reliably trigger this as follows: BUG: KASAN: stack-out-of-bounds in copy_valid_id_string sound/core/init.c:696 [inline] BUG: KASAN: stack-out-of-bounds in snd_card_set_id_no_lock+0x698/0x74c sound/core/init.c:718 The off-by-one has been present since commit bafeee5b1f8d ("ALSA: snd_usb_caiaq: give better shortname") from June 2009 (v2.6.31-rc1), which first introduced this whitespace-stripping loop. The original code never accounted for the null terminator when bounding the copy. Fix this by changing the loop bound to `sizeof(card->id) - 1`, ensuring at least one byte remains as the null terminator. Fixes: bafeee5b1f8d ("ALSA: snd_usb_caiaq: give better shortname") Cc: stable@vger.kernel.org Cc: Andrey Konovalov Reported-by: Berk Cem Goksel Signed-off-by: Berk Cem Goksel Link: https://patch.msgid.link/20260329133825.581585-1-berkcgoksel@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/caiaq/device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/usb/caiaq/device.c +++ b/sound/usb/caiaq/device.c @@ -488,7 +488,7 @@ static int init_card(struct snd_usb_caia memset(id, 0, sizeof(id)); for (c = card->shortname, len = 0; - *c && len < sizeof(card->id); c++) + *c && len < sizeof(card->id) - 1; c++) if (*c != ' ') id[len++] = *c;