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 917AD3624B0; Wed, 8 Apr 2026 18:44:20 +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=1775673860; cv=none; b=AOl9yBD4OsuOZajzte9CKD1PI6FV90Q2fL1dgCxIuwrNzFgsQ33TfqG/f8h8foQ9YjptxdFy9AObM/kK1LB2vxSi4/TeqjpKqoAtvE9KmKYF8+wq3d4Q6HkbzSakFNlR623S/8foimy31vbkl3F9EhEjIAVtbamCq8qU1R4KCnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673860; c=relaxed/simple; bh=tb9tDbKh7oyAsE39dDHPY0wUpvhiOYt47VBBL6rkizk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LqXepzwepNptYstaOJQ+TQJbFn0YkeN1xlh6AUKz/ijvDV+j/uPajU0onkaNq3VCP6rWfq1+lxmhnerBZ5PJnpbfl9k9YZV6dWDwwkV7ILzSWP9ryE0Sp70y5jGWsyU5GA1St9w3kSfeSQSHJbKgIf1ublNT7EKBKkyM1R9TVNk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vP32YE0B; 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="vP32YE0B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27CA4C2BCB1; Wed, 8 Apr 2026 18:44:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775673860; bh=tb9tDbKh7oyAsE39dDHPY0wUpvhiOYt47VBBL6rkizk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vP32YE0BJXwT0oXPPkqOATrmr39nfFo1mxfRD2sChEBffzl8hrjah+2bJHxQ2LUOU w1nk0E50wCbB5Mg+YdBsb5LoT7bgwiJorAtrui2KUSL6IFRymzQ7+kjbbQhSC6X4un j+4q2HwW1uLyR3m6xNUmqnp4gvDxFJE+qmBD7T+I= 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 6.12 118/242] ALSA: caiaq: fix stack out-of-bounds read in init_card Date: Wed, 8 Apr 2026 20:02:38 +0200 Message-ID: <20260408175931.503841714@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175927.064985309@linuxfoundation.org> References: <20260408175927.064985309@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 6.12-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;