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authorTakashi Iwai <tiwai@suse.de>2018-01-08 13:58:31 +0100
committerTakashi Iwai <tiwai@suse.de>2018-01-08 15:16:52 +0100
commit29159a4ed7044c52e3e2cf1a9fb55cec4745c60b (patch)
tree84f30f823082ca2dc6b1ef39802b52deed27a3b8 /sound/core/oss
parent898dfe4687f460ba337a01c11549f87269a13fa2 (diff)
downloadlinux-29159a4ed7044c52e3e2cf1a9fb55cec4745c60b.tar.bz2
ALSA: pcm: Abort properly at pending signal in OSS read/write loops
The loops for read and write in PCM OSS emulation have no proper check of pending signals, and they keep processing even after user tries to break. This results in a very long delay, often seen as RCU stall when a huge unprocessed bytes remain queued. The bug could be easily triggered by syzkaller. As a simple workaround, this patch adds the proper check of pending signals and aborts the loop appropriately. Reported-by: syzbot+993cb4cfcbbff3947c21@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/oss')
-rw-r--r--sound/core/oss/pcm_oss.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index ceaa51f76591..e317964bd2ea 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1381,6 +1381,10 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha
tmp != runtime->oss.period_bytes)
break;
}
+ if (signal_pending(current)) {
+ tmp = -ERESTARTSYS;
+ goto err;
+ }
}
mutex_unlock(&runtime->oss.params_lock);
return xfer;
@@ -1466,6 +1470,10 @@ static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __use
bytes -= tmp;
xfer += tmp;
}
+ if (signal_pending(current)) {
+ tmp = -ERESTARTSYS;
+ goto err;
+ }
}
mutex_unlock(&runtime->oss.params_lock);
return xfer;