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.blackw...@ccur.com>
Index: b/kernel/debug/kdb/kdb_main.c
===================================================================
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -3341,7 +3341,7 @@ 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;
--
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