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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2011-12-27 11:25:46 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2011-12-27 11:25:48 +0100
commit1fb810576f0e92451a5d46774bbd593946ca3526 (patch)
tree64916e26ab8b5773cc76d05260560a36bcf7a6a4 /arch/s390
parent272f01bf9b6da93f49fcca2656c24da8d2cfcc09 (diff)
downloadlinux-1fb810576f0e92451a5d46774bbd593946ca3526.tar.bz2
[S390] Check for NULL termination in command line setup
The current code in setup_boot_command_line() uses a heuristic to detect an EBCDIC command line. It checks if any of the bytes in the command line has bit one (0x80) set. In that case it is assumed that we have an EBCDIC string and the complete command line is converted. On s390 there are cases where the boot loader provides a kernel command line that is NULL terminated, but has random data after the NULL termination. In that case, setup_boot_command_line() might misinterpret an ASCII string for an EBCDIC string. A subsequent string conversion can then damage the ASCII string. This patch solves the problem by checking for NULL termination. If no EBCDIC character has been found until the the NULL termination has been found, we now assume that we have an ASCII string. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/early.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index c9ffe0025197..52098d6dfaa7 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -434,18 +434,22 @@ static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
}
}
-static void __init setup_boot_command_line(void)
+static inline int has_ebcdic_char(const char *str)
{
int i;
- /* convert arch command line to ascii */
- for (i = 0; i < ARCH_COMMAND_LINE_SIZE; i++)
- if (COMMAND_LINE[i] & 0x80)
- break;
- if (i < ARCH_COMMAND_LINE_SIZE)
- EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
- COMMAND_LINE[ARCH_COMMAND_LINE_SIZE-1] = 0;
+ for (i = 0; str[i]; i++)
+ if (str[i] & 0x80)
+ return 1;
+ return 0;
+}
+static void __init setup_boot_command_line(void)
+{
+ COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
+ /* convert arch command line to ascii if necessary */
+ if (has_ebcdic_char(COMMAND_LINE))
+ EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
/* copy arch command line */
strlcpy(boot_command_line, strstrip(COMMAND_LINE),
ARCH_COMMAND_LINE_SIZE);