From 1fb810576f0e92451a5d46774bbd593946ca3526 Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Tue, 27 Dec 2011 11:25:46 +0100 Subject: [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 Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/early.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'arch/s390') 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); -- cgit v1.2.2