Commit f7c82d5a authored Dec 10, 2012 by John Blackwood Committed by Jason Wessel Mar 02, 2013

kdb: A fix for kdb command table expansion

When locally adding in some additional kdb commands, I stumbled
across an issue with the dynamic expansion of the kdb command table.
When the number of kdb commands exceeds the size of the statically
allocated kdb_base_commands[] array, additional space is allocated in
the kdb_register_repeat() routine.

The unused portion of the newly allocated array was not being initialized
to zero properly and this would result in segfaults when help '?' was
executed or when a search for a non-existing command would traverse the
command table beyond the end of valid command entries and then attempt
to use the non-zeroed area as actual command entries.

Signed-off-by: John Blackwood <john.blackwood@ccur.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

parent 19f949f5

kernel/debug/kdb/kdb_main.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2739,7 +2739,7 @@ int kdb_register_repeat(char *cmd,
		(kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
		kfree(kdb_commands);
		}
		memset(new + kdb_max_commands, 0,
		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
		kdb_command_extend * sizeof(*new));
		kdb_commands = new;
		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;