From b2a297dc9c19650359dd544c2c5f1fcaae436895 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 21 Mar 2017 13:56:04 +0100 Subject: [PATCH] ALSA: seq: Fix racy cell insertions during snd_seq_pool_done() commit c520ff3d03f0b5db7146d9beed6373ad5d2a5e0e upstream. When snd_seq_pool_done() is called, it marks the closing flag to refuse the further cell insertions. But snd_seq_pool_done() itself doesn't clear the cells but just waits until all cells are cleared by the caller side. That is, it's racy, and this leads to the endless stall as syzkaller spotted. This patch addresses the racy by splitting the setup of pool->closing flag out of snd_seq_pool_done(), and calling it properly before snd_seq_pool_done(). BugLink: http://lkml.kernel.org/r/CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.com Reported-and-tested-by: Dmitry Vyukov Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings --- Reading git-format-patch failed