github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-12 04:23:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

s390/boot: Avoid IPL parameter append past command line

Browse Source 
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: 5ecb2da660 ("s390: support command lines longer than 896 bytes")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Vasily Gorbik 2026-08-19 12:30:33 +02:00 committed by Heiko Carstens
parent a0c798ed41
commit d76181dfab
1 changed files with 12 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
arch/s390/boot/ipl_parm.c
View File

@ -23,6 +23,7 @@ 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);
@ -135,31 +136,29 @@ 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);
}
}
}
@ -245,7 +244,6 @@ 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;