From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 835E0509EF9; Wed, 30 Sep 2026 17:09:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790788141; cv=none; b=W+h6G3gcl53QFOSpSzDG6eQKmexot2axU6Wk8eajqpXNiYIGZA1nZytCCUGEcfkPjjTo2tEbIudTmlGCPRWm55I/51JYy/dU/Iw207gcKhwCHd4ormmh/YmD+IcfKknDnLfTBbmM2hKjgbjxtxOpyDWq10F0zlhxkebmn6nD59c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790788141; c=relaxed/simple; bh=CgZ2FrKLZbY7U2Sn8WaMM/ZpPVT+OcaNIywIer5Yyvk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uB+HlQFs9gAqoej9/K15UOc35cp0nOD1CdUzbHuYfBheqe+Se64n3IVDnTeQKqEeRZ3OcXqlVkrDyGOADlPHfmCstnHg6GBeQ69jaD3/XWinluEDYZDdEZw6QYuXH8wANKD9cg8VnJK1v33sLEZ1UowczFejZO+JZfw354Boyy0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sJmxATPn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sJmxATPn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC1E91F000FF; Wed, 30 Sep 2026 17:08:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790788140; bh=nvdKeqi2NuFc1T7SI2Ij9LYUnaSAkuKSpzjo0i8n78Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sJmxATPnzLOXhDFczOrWBxCfeOJ9GP39X0ReNzIZKGQw11Lhsl8GbgszrfKAvyJef fVsNRhGCJwwYtBcJEYsivc7eoqKJZmW9lJc2WtqgFe+hxKeppB1PHwQ7tiEBJ3fz15 8ux5GIF78nqziClO5ko2vkSaZNmuAeapEo4waiZg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Heiko Carstens , Vasily Gorbik , Sasha Levin Subject: [PATCH 6.12 009/877] s390/boot: Avoid IPL parameter append past command line Date: Wed, 30 Sep 2026 17:15:20 +0200 Message-ID: <20260930152414.946814908@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152414.738996857@linuxfoundation.org> References: <20260930152414.738996857@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vasily Gorbik [ Upstream commit d76181dfabdaa720703167393704efacba343442 ] A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains. Fixes: 5ecb2da660ab ("s390: support command lines longer than 896 bytes") Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/boot/ipl_parm.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c index 557462e62cd73..6c77afb3b8a11 100644 --- a/arch/s390/boot/ipl_parm.c +++ b/arch/s390/boot/ipl_parm.c @@ -21,6 +21,7 @@ struct parmarea parmarea __section(".parmarea") = { }; char __bootdata(early_command_line)[COMMAND_LINE_SIZE]; +static char command_line_buf[COMMAND_LINE_SIZE]; unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL; struct ipl_parameter_block __bootdata_preserved(ipl_block); @@ -148,31 +149,29 @@ static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size, static void append_ipl_block_parm(void) { - char *parm, *delim; - size_t len, rc = 0; + size_t len, extra = 0; + char *delim; len = strlen(early_command_line); - - delim = early_command_line + len; /* '\0' character position */ - parm = early_command_line + len + 1; /* append right after '\0' */ + delim = early_command_line + len; /* '\0' character position */ switch (ipl_block.pb0_hdr.pbt) { case IPL_PBT_CCW: - rc = ipl_block_get_ascii_vmparm( - parm, COMMAND_LINE_SIZE - len - 1, &ipl_block); + extra = ipl_block_get_ascii_vmparm(command_line_buf, sizeof(command_line_buf), &ipl_block); break; case IPL_PBT_FCP: case IPL_PBT_NVME: case IPL_PBT_ECKD: - rc = ipl_block_get_ascii_scpdata( - parm, COMMAND_LINE_SIZE - len - 1, &ipl_block); + extra = ipl_block_get_ascii_scpdata(command_line_buf, sizeof(command_line_buf), &ipl_block); break; } - if (rc) { - if (*parm == '=') - memmove(early_command_line, parm + 1, rc); - else + if (extra) { + if (command_line_buf[0] == '=') { + memmove(early_command_line, command_line_buf + 1, extra); + } else if (len < COMMAND_LINE_SIZE - 2) { *delim = ' '; /* replace '\0' with space */ + sized_strscpy(delim + 1, command_line_buf, COMMAND_LINE_SIZE - len - 1); + } } } @@ -258,7 +257,6 @@ static void modify_fac_list(char *str) check_cleared_facilities(); } -static char command_line_buf[COMMAND_LINE_SIZE]; void parse_boot_command_line(void) { char *param, *val; -- 2.53.0