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 9487F146586; Thu, 13 Jun 2024 12:04:17 +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=1718280257; cv=none; b=dx100WhXmBfCShGDFRICdb8FsDcHYJf9bpYvSoLVHQMBJupvhYfGRXLYPqcN2s6aMtHEv1Ol+EoYDj48meKNE0Erej9fbVpLTiqxTwWFv/I/R9uPJZE8J13/KwmY9jCXwV7rJE5dPhNKLHBQjLF86nIgihiiljWZILTsOEsP/EQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718280257; c=relaxed/simple; bh=EkzQtEhpzGtlwfNv863lAZ/FN56nT2VJFMTSeRIITUQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=My8OLK4mmKbtv3gJvM04MhgsuXeRZw06gzr//62Pz9xi/UuJw9xYluiIlDfIRLyW8ftI9JIHCQwaPQhDvaXqH9QvjOs+AWWv6isgcopbF87L9vJeMAj5+bPLErdoz5TlPUVfoa0FOmDjGnlNSyItMgMjfGqBERL2vE3vZXI+WL4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zPiuWBXv; 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="zPiuWBXv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19D98C4AF1A; Thu, 13 Jun 2024 12:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718280257; bh=EkzQtEhpzGtlwfNv863lAZ/FN56nT2VJFMTSeRIITUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zPiuWBXvgNwjMGRyTmvRqvQ/Kc0oPpi+HO+ea7Kb3jmbGtepjwj5GYdgy/y+WNkdk MgxxVIjeMYwYjbfcZDuKZSSgKMNKEy0NZAjfXCdLxRk57cypMZOjOUJTgfP5o1g8Qh INA3z9CHzhIe3jRM/IIMYHnkMJbpWcACWHmJokcw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Douglas Anderson , Justin Stitt , Daniel Thompson Subject: [PATCH 5.4 196/202] kdb: Use format-specifiers rather than memset() for padding in kdb_read() Date: Thu, 13 Jun 2024 13:34:54 +0200 Message-ID: <20240613113235.304649660@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113227.759341286@linuxfoundation.org> References: <20240613113227.759341286@linuxfoundation.org> User-Agent: quilt/0.67 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 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Thompson commit c9b51ddb66b1d96e4d364c088da0f1dfb004c574 upstream. Currently when the current line should be removed from the display kdb_read() uses memset() to fill a temporary buffer with spaces. The problem is not that this could be trivially implemented using a format string rather than open coding it. The real problem is that it is possible, on systems with a long kdb_prompt_str, to write past the end of the tmpbuffer. Happily, as mentioned above, this can be trivially implemented using a format string. Make it so! Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson Tested-by: Justin Stitt Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-5-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman --- kernel/debug/kdb/kdb_io.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -315,11 +315,9 @@ poll_again: break; case 14: /* Down */ case 16: /* Up */ - memset(tmpbuffer, ' ', - strlen(kdb_prompt_str) + (lastchar-buffer)); - *(tmpbuffer+strlen(kdb_prompt_str) + - (lastchar-buffer)) = '\0'; - kdb_printf("\r%s\r", tmpbuffer); + kdb_printf("\r%*c\r", + (int)(strlen(kdb_prompt_str) + (lastchar - buffer)), + ' '); *lastchar = (char)key; *(lastchar+1) = '\0'; return lastchar;