From: Shang XiaoJing shangxiaojing@huawei.com

test_gen_synth_cmd() only free buf in fail path, hence buf will leak when there is no failure. Add kfree(buf) to prevent the memleak. The same reason and solution in test_empty_synth_event().

unreferenced object 0xffff8881127de000 (size 2048): comm "modprobe", pid 247, jiffies 4294972316 (age 78.756s) hex dump (first 32 bytes): 20 67 65 6e 5f 73 79 6e 74 68 5f 74 65 73 74 20 gen_synth_test 20 70 69 64 5f 74 20 6e 65 78 74 5f 70 69 64 5f pid_t next_pid_ backtrace: [<000000004254801a>] kmalloc_trace+0x26/0x100 [<0000000039eb1cf5>] 0xffffffffa00083cd [<000000000e8c3bc8>] 0xffffffffa00086ba [<00000000c293d1ea>] do_one_initcall+0xdb/0x480 [<00000000aa189e6d>] do_init_module+0x1cf/0x680 [<00000000d513222b>] load_module+0x6a50/0x70a0 [<000000001fd4d529>] __do_sys_finit_module+0x12f/0x1c0 [<00000000b36c4c0f>] do_syscall_64+0x3f/0x90 [<00000000bbf20cf3>] entry_SYSCALL_64_after_hwframe+0x63/0xcd unreferenced object 0xffff8881127df000 (size 2048): comm "modprobe", pid 247, jiffies 4294972324 (age 78.728s) hex dump (first 32 bytes): 20 65 6d 70 74 79 5f 73 79 6e 74 68 5f 74 65 73 empty_synth_tes 74 20 20 70 69 64 5f 74 20 6e 65 78 74 5f 70 69 t pid_t next_pi backtrace: [<000000004254801a>] kmalloc_trace+0x26/0x100 [<00000000d4db9a3d>] 0xffffffffa0008071 [<00000000c31354a5>] 0xffffffffa00086ce [<00000000c293d1ea>] do_one_initcall+0xdb/0x480 [<00000000aa189e6d>] do_init_module+0x1cf/0x680 [<00000000d513222b>] load_module+0x6a50/0x70a0 [<000000001fd4d529>] __do_sys_finit_module+0x12f/0x1c0 [<00000000b36c4c0f>] do_syscall_64+0x3f/0x90 [<00000000bbf20cf3>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Link: https://lkml.kernel.org/r/20221117012346.22647-2-shangxiaojing@huawei.com

Cc: mhiramat@kernel.org Cc: zanussi@kernel.org Cc: fengguang.wu@intel.com Cc: stable@vger.kernel.org Fixes: 9fe41efaca08 ("tracing: Add synth event generation test module") Signed-off-by: Shang XiaoJing shangxiaojing@huawei.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- kernel/trace/synth_event_gen_test.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/synth_event_gen_test.c b/kernel/trace/synth_event_gen_test.c index 0b15e975d2c2..8d77526892f4 100644 --- a/kernel/trace/synth_event_gen_test.c +++ b/kernel/trace/synth_event_gen_test.c @@ -120,15 +120,13 @@ static int __init test_gen_synth_cmd(void)

/* Now generate a gen_synth_test event */ ret = synth_event_trace_array(gen_synth_test, vals, ARRAY_SIZE(vals)); - out: + free: + kfree(buf); return ret; delete: /* We got an error after creating the event, delete it */ synth_event_delete("gen_synth_test"); - free: - kfree(buf); - - goto out; + goto free; }

/* @@ -227,15 +225,13 @@ static int __init test_empty_synth_event(void)

/* Now trace an empty_synth_test event */ ret = synth_event_trace_array(empty_synth_test, vals, ARRAY_SIZE(vals)); - out: + free: + kfree(buf); return ret; delete: /* We got an error after creating the event, delete it */ synth_event_delete("empty_synth_test"); - free: - kfree(buf); - - goto out; + goto free; }

static struct synth_field_desc create_synth_test_fields[] = {