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 732943FFE; Tue, 23 Jan 2024 00:11:35 +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=1705968695; cv=none; b=BodpA0BRaz4zHezqdVr4NlEdtOFRngGFx1WcexOxSp30vRhnjAnYgdY1exAkmrzy4IddY3k8whvV1/ivcB7GB7tuDfoKpZ7j84emTbk3MV6GTdC5OpC6cuw77X0Qi6a9B1usFPHvjHBB1Te9Uxx/UfMhJSLl6PV953QL2XqXDws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705968695; c=relaxed/simple; bh=sgTQDqZhLt9pksrZs2MP1RcoDJkJlO4X+YtUe80qDCM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NfXreVbdTcZSkIrHi7R5SJPswB0m+y13Z/awlykvqjFBdp3a7M3oy7ttBOwzJJHAoiMyuf9Q+cqXpn2d4REiMwXWYrZ5SfhSDj3AtY4wbcGoWl3kh5AqImal4Ppvb9gBqkUV6xlJW+4mUp3KNy2l6yaU8NPiUGIOeUX/W4vYcAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CysK21aH; 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="CysK21aH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3292FC433F1; Tue, 23 Jan 2024 00:11:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705968695; bh=sgTQDqZhLt9pksrZs2MP1RcoDJkJlO4X+YtUe80qDCM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CysK21aHTaNQx+WmOdDV1RUvzOixq6y58cmgwosRh3oT9J4Vi5Y0pzhOjR5c4PyRa hhz/+KrYLAtoyKukgXiXI9A3P0MlRfYEwfgCF1R92/aRSjavnVRjKSdN8dAN8jvUfF x1UUsVz0aAddvCobQXxEfxMmKb5tkyajjt8bBH68= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christophe JAILLET , Douglas Anderson , Sasha Levin Subject: [PATCH 4.19 144/148] kdb: Fix a potential buffer overflow in kdb_local() Date: Mon, 22 Jan 2024 15:58:20 -0800 Message-ID: <20240122235718.442439718@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235712.442097787@linuxfoundation.org> References: <20240122235712.442097787@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christophe JAILLET [ Upstream commit 4f41d30cd6dc865c3cbc1a852372321eba6d4e4c ] When appending "[defcmd]" to 'kdb_prompt_str', the size of the string already in the buffer should be taken into account. An option could be to switch from strncat() to strlcat() which does the correct test to avoid such an overflow. However, this actually looks as dead code, because 'defcmd_in_progress' can't be true here. See a more detailed explanation at [1]. [1]: https://lore.kernel.org/all/CAD=FV=WSh7wKN7Yp-3wWiDgX4E3isQ8uh0LCzTmd1v9Cg9j+nQ@mail.gmail.com/ Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Christophe JAILLET Reviewed-by: Douglas Anderson Signed-off-by: Sasha Levin --- kernel/debug/kdb/kdb_main.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 8f31d472384f..7f78657dfa00 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1309,8 +1309,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, /* PROMPT can only be set if we have MEM_READ permission. */ snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"), raw_smp_processor_id()); - if (defcmd_in_progress) - strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN); /* * Fetch command from keyboard -- 2.43.0