From: Suzuki K. Poulose <suzuki@xxxxxxxxxx>
Enforce size check for kernel command line to make sure it
doesn't overflow COMMAND_LINE_SIZE.
Reported-by: Nathan D. Miller <nathanm2 at us.ibm.com>
Signed-off-by: Suzuki K. Poulose <suzuki at in.ibm.com>
---
kexec/arch/ppc/kexec-elf-ppc.c | 29 ++++++++++++++++-------------
kexec/arch/ppc/kexec-uImage-ppc.c | 23 ++++++++++++++---------
2 files changed, 30 insertions(+), 22 deletions(-)
diff --git a/kexec/arch/ppc/kexec-elf-ppc.c b/kexec/arch/ppc/kexec-elf-ppc.c
index 3daca2d..98cae9c 100644
--- a/kexec/arch/ppc/kexec-elf-ppc.c
+++ b/kexec/arch/ppc/kexec-elf-ppc.c
@@ -157,7 +157,7 @@ int elf_ppc_load(int argc, char **argv, const char *buf, off_t len,
struct mem_ehdr ehdr;
char *command_line, *crash_cmdline, *cmdline_buf;
char *tmp_cmdline;
- int command_line_len;
+ int command_line_len, crash_cmdline_len;
char *dtb;
int result;
char *error_msg;
@@ -244,19 +244,10 @@ int elf_ppc_load(int argc, char **argv, const char *buf, off_t len,
} else {
command_line = get_command_line();
}
- command_line_len = strlen(command_line) + 1;
+ command_line_len = strlen(command_line);
fixup_nodes[cur_fixup] = NULL;
- /* Need to append some command line parameters internally in case of
- * taking crash dumps.
- */
- if (info->kexec_flags & KEXEC_ON_CRASH) {
- crash_cmdline = xmalloc(COMMAND_LINE_SIZE);
- memset((void *)crash_cmdline, 0, COMMAND_LINE_SIZE);
- } else
- crash_cmdline = NULL;
-
/* Parse the Elf file */
result = build_elf_exec_info(buf, len, &ehdr, 0);
if (result < 0) {
@@ -292,16 +283,23 @@ int elf_ppc_load(int argc, char **argv, const char *buf, off_t len,
goto out;
}
- /* If panic kernel is being loaded, additional segments need
- * to be created.
+ /*
+ * Need to append some command line parameters internally in case of
+ * taking crash dumps. Additional segments need to be created.
*/
if (info->kexec_flags & KEXEC_ON_CRASH) {
+ crash_cmdline = xmalloc(COMMAND_LINE_SIZE);
+ memset((void *)crash_cmdline, 0, COMMAND_LINE_SIZE);
result = load_crashdump_segments(info, crash_cmdline,
max_addr, 0);
if (result < 0) {
result = -1;
goto out;
}
+ crash_cmdline_len = strlen(crash_cmdline);
+ } else {
+ crash_cmdline = NULL;
+ crash_cmdline_len = 0;
}
/*
@@ -337,6 +335,11 @@ int elf_ppc_load(int argc, char **argv, const char *buf, off_t len,
info->entry = (void *)arg_base;
#else
+ if (crash_cmdline_len + command_line_len + 1 > COMMAND_LINE_SIZE) {
+ printf("Kernel command line exceeds size\n");
+ return -1;
+ }
+
cmdline_buf = xmalloc(COMMAND_LINE_SIZE);
memset((void *)cmdline_buf, 0, COMMAND_LINE_SIZE);
if (command_line)
diff --git a/kexec/arch/ppc/kexec-uImage-ppc.c b/kexec/arch/ppc/kexec-uImage-ppc.c
index 9113fbe..008463b 100644
--- a/kexec/arch/ppc/kexec-uImage-ppc.c
+++ b/kexec/arch/ppc/kexec-uImage-ppc.c
@@ -82,7 +82,7 @@ static int ppc_load_bare_bits(int argc, char **argv, const char *buf,
{
char *command_line, *cmdline_buf, *crash_cmdline;
char *tmp_cmdline;
- int command_line_len;
+ int command_line_len, crash_cmdline_len;
char *dtb;
unsigned int addr;
unsigned long dtb_addr;
@@ -178,29 +178,34 @@ static int ppc_load_bare_bits(int argc, char **argv, const char *buf,
add_segment(info, buf, len, load_addr, len + _1MiB);
+
if (info->kexec_flags & KEXEC_ON_CRASH) {
crash_cmdline = xmalloc(COMMAND_LINE_SIZE);
memset((void *)crash_cmdline, 0, COMMAND_LINE_SIZE);
- } else
- crash_cmdline = NULL;
-
- if (info->kexec_flags & KEXEC_ON_CRASH) {
ret = load_crashdump_segments(info, crash_cmdline,
max_addr, 0);
if (ret < 0) {
ret = -1;
goto out;
}
+ crash_cmdline_len = strlen(crash_cmdline);
+ } else {
+ crash_cmdline = NULL;
+ crash_cmdline_len = 0;
+ }
+
+ if (crash_cmdline_len + command_line_len + 1 > COMMAND_LINE_SIZE) {
+ printf("Kernel command line exceeds maximum possible length\n");
+ return -1;
}
cmdline_buf = xmalloc(COMMAND_LINE_SIZE);
memset((void *)cmdline_buf, 0, COMMAND_LINE_SIZE);
+
if (command_line)
- strncat(cmdline_buf, command_line, command_line_len);
+ strcpy(cmdline_buf, command_line);
if (crash_cmdline)
- strncat(cmdline_buf, crash_cmdline,
- sizeof(crash_cmdline) -
- strlen(crash_cmdline) - 1);
+ strncat(cmdline_buf, crash_cmdline, crash_cmdline_len);
elf_rel_build_load(info, &info->rhdr, (const char *)purgatory,
purgatory_size, 0, -1, -1, 0);
--
1.7.1
