Re: [BUG] ALSA: core: seq: a possible double-lock bug in snd_seq_midisynth_remove()
On Mon, 29 Jul 2019 05:54:07 +0200, Jia-Ju Bai wrote: > > In snd_seq_midisynth_remove(), there is a possible double-lock bug: > snd_seq_midisynth_remove() > mutex_lock(_mutex); -- line 421 > snd_seq_delete_kernel_client() --- line 436 > seq_free_client() -- line 2244 > mutex_lock(_mutex); -- line 294 > > This bug is found by a static analysis tool STCheck written by us. No, it's a false-positive report. Both register_mutex's are static, hence they are local to each file. That is, you're looking at two different mutexes. Takashi
[BUG] ALSA: core: seq: a possible double-lock bug in snd_seq_midisynth_remove()
In snd_seq_midisynth_remove(), there is a possible double-lock bug: snd_seq_midisynth_remove() mutex_lock(_mutex); -- line 421 snd_seq_delete_kernel_client() --- line 436 seq_free_client() -- line 2244 mutex_lock(_mutex); -- line 294 This bug is found by a static analysis tool STCheck written by us. I do not know how to correctly fix this bug, so I only report it. A possible fix is to release the mutex lock before calling seq_free_client() in snd_seq_delete_kernel_client() and then acquiring the lock again after calling seq_free_client(). Best wishes, Jia-Ju Bai
