From 5fae054c2b5a7c10475d2e425dfea0c567c1c5dd Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 2 Feb 2016 12:48:09 +0300 Subject: [PATCH] goldfish: locking bugs in goldfish_pipe_read_write() We recently messed up the error handling here. We can return with the pipe->lock held or sometimes we unlock twice by mistake. Fixes: 2f3be88237a3 ('goldfish_pipe: Pin pages to memory while copying and other cleanups') Signed-off-by: Dan Carpenter Reviewed-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman --- drivers/platform/goldfish/goldfish_pipe.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index e3fab9a1d9f7..839df4aace76 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -313,7 +313,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, !is_write, 0, &page, NULL); up_read(¤t->mm->mmap_sem); if (ret < 0) - return ret; + break; if (dev->version) { /* Device version 1 or newer (qemu-android) expects the @@ -400,22 +400,16 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, while (test_bit(wakeBit, &pipe->flags)) { if (wait_event_interruptible( pipe->wake_queue, - !test_bit(wakeBit, &pipe->flags))) { - ret = -ERESTARTSYS; - break; - } - - if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) { - ret = -EIO; - break; - } + !test_bit(wakeBit, &pipe->flags))) + return -ERESTARTSYS; + + if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) + return -EIO; } /* Try to re-acquire the lock */ - if (mutex_lock_interruptible(&pipe->lock)) { - ret = -ERESTARTSYS; - break; - } + if (mutex_lock_interruptible(&pipe->lock)) + return -ERESTARTSYS; } mutex_unlock(&pipe->lock); -- 2.20.1