Ihor and Kumar reported splat from ftrace_get_addr_curr [1], which happened because of the missing ftrace_lock in update_ftrace_direct_add/del functions allowing concurrent access to ftrace internals. The ftrace_update_ops function must be guarded by ftrace_lock, adding that. Fixes: 05dc5e9c1fe1 ("ftrace: Add update_ftrace_direct_add function") Fixes: 8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function") Reported-by: Ihor Solodrai Reported-by: Kumar Kartikeya Dwivedi Closes: https://lore.kernel.org/bpf/1b58ffb2-92ae-433a-ba46-95294d6edea2@linux.dev/ Tested-by: Ihor Solodrai Signed-off-by: Jiri Olsa --- kernel/trace/ftrace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 827fb9a0bf0d..8baf61c9be6d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6404,6 +6404,7 @@ int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash) new_filter_hash = old_filter_hash; } } else { + guard(mutex)(&ftrace_lock); err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH); /* * new_filter_hash is dup-ed, so we need to release it anyway, @@ -6530,6 +6531,7 @@ int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash) ops->func_hash->filter_hash = NULL; } } else { + guard(mutex)(&ftrace_lock); err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH); /* * new_filter_hash is dup-ed, so we need to release it anyway, -- 2.53.0