kdb: fix crash when KDB_BASE_CMD_MAX is exceeded
When the number of dyanmic kdb commands exceeds KDB_BASE_CMD_MAX, the
kernel will fault.
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 3ab3fee..a6e7297 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -82,7 +82,7 @@
#define for_each_kdbcmd(cmd, num) \
for ((cmd) = kdb_base_commands, (num) = 0; \
num < kdb_max_commands; \
- num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++, num++)
+ num++, num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++)
typedef struct _kdbmsg {
int km_diag; /* kdb diagnostic */
@@ -646,7 +646,7 @@
}
if (!s->usable)
return KDB_NOTIMP;
- s->command = kmalloc((s->count + 1) * sizeof(*(s->command)), GFP_KDB);
+ s->command = kzalloc((s->count + 1) * sizeof(*(s->command)), GFP_KDB);
if (!s->command) {
kdb_printf("Could not allocate new kdb_defcmd table for %s\n",
cmdstr);
@@ -2740,13 +2740,13 @@
}
if (kdb_commands) {
memcpy(new, kdb_commands,
- kdb_max_commands * sizeof(*new));
+ (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
kfree(kdb_commands);
}
memset(new + kdb_max_commands, 0,
kdb_command_extend * sizeof(*new));
kdb_commands = new;
- kp = kdb_commands + kdb_max_commands;
+ kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
kdb_max_commands += kdb_command_extend;
}