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authorDan Carpenter <dan.carpenter@oracle.com>2016-02-02 10:48:09 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-08 06:26:57 +0100
commit5fae054c2b5a7c10475d2e425dfea0c567c1c5dd (patch)
treedda71124754c5cf778acd00a8bc51c1556e7b636
parentmisc: mic: fix incorrect use of error codes in SCIF DMA driver (diff)
downloadlinux-5fae054c2b5a7c10475d2e425dfea0c567c1c5dd.tar.xz
linux-5fae054c2b5a7c10475d2e425dfea0c567c1c5dd.zip
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 <dan.carpenter@oracle.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/platform/goldfish/goldfish_pipe.c22
1 files 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(&current->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);