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 80C9126B971; Mon, 13 Apr 2026 16:37:13 +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=1776098233; cv=none; b=FBhPfKfSUObHMKFuDiForDg6cceGpkiIb1sDQ55YEfDWnkUBZmbruBy+WKtiqCwG6KpZ063oEOGLgO2cfvyYd6qb8S7vDJFe6JeYunmkUi5x4yxkYPe6kr3j/l1AxjUMOdU3RgN1g1UFnLISSQHvCSFhenIM7vItP7lbXhHUc0k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098233; c=relaxed/simple; bh=bxQ4RrwIKxtYSt6kiD8pj59FIdRDNKpEv0POt+q0MQ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Iz2rzUeMZQIQB4nGwM1L1/pKRfLpOdD7VjBRLmRUMfZCXxiNdRKyt4lTVfK8rerqVhGkz/bRLGpAVWpeKWoUUR+1ycnd8pFYPphiJYf8n1aIpdbvcjoFqHvALjkf3Yop82gelALDJpGOWGxwi0R/M13lptG58MxkxkuEmFOskTU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fBCNB3Ze; 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="fBCNB3Ze" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18AA7C2BCAF; Mon, 13 Apr 2026 16:37:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776098233; bh=bxQ4RrwIKxtYSt6kiD8pj59FIdRDNKpEv0POt+q0MQ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fBCNB3ZeH1qbTp7b0ad/hHaBpVplR3KiXwPHL4FRQ/+321Ffjk5QYN4eHoaPDASup D+a0Us+V8eC0LRcCK5hvKiq7uwiXW/HrBl4Ex7NtNmU+NeTSg8cT+8nsUa6OeUXS2u 0J069JeCPtJ0IlvCOhUBxiFC1hSeoIFa+S1QWRlg= 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 5.15 446/570] ALSA: caiaq: fix stack out-of-bounds read in init_card Date: Mon, 13 Apr 2026 17:59:37 +0200 Message-ID: <20260413155847.177631035@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155830.386096114@linuxfoundation.org> References: <20260413155830.386096114@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 5.15-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;