From: Wenwen Wang <wang6495@xxxxxxx> commit 91862cc7867bba4ee5c8fcf0ca2f1d30427b6129 upstream. In trace_pid_write(), the buffer for trace parser is allocated through kmalloc() in trace_parser_get_init(). Later on, after the buffer is used, it is then freed through kfree() in trace_parser_put(). However, it is possible that trace_pid_write() is terminated due to unexpected errors, e.g., ENOMEM. In that case, the allocated buffer will not be freed, which is a memory leak bug. To fix this issue, free the allocated buffer when an error is encountered. Link: http://lkml.kernel.org/r/1555726979-15633-1-git-send-email-wang6495@xxxxxxx Fixes: f4d34a87e9c10 ("tracing: Use pid bitmap instead of a pid array for set_event_pid") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Wenwen Wang <wang6495@xxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -496,8 +496,10 @@ int trace_pid_write(struct trace_pid_lis * not modified. */ pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); - if (!pid_list) + if (!pid_list) { + trace_parser_put(&parser); return -ENOMEM; + } pid_list->pid_max = READ_ONCE(pid_max); @@ -507,6 +509,7 @@ int trace_pid_write(struct trace_pid_lis pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); if (!pid_list->pids) { + trace_parser_put(&parser); kfree(pid_list); return -ENOMEM; }
