[PATCH 4.4 072/104] media: vb2: be sure to unlock mutex on errors

From: Greg Kroah-Hartman
Date: Thu Jan 24 2019 - 15:11:07 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>

commit c06ef2e9acef4cda1feee2ce055b8086e33d251a upstream.

As reported by smatch:
drivers/media/common/videobuf2/videobuf2-core.c: drivers/media/common/videobuf2/videobuf2-core.c:2159 vb2_mmap() warn: inconsistent returns 'mutex:&q->mmap_lock'.
Locked on: line 2148
Unlocked on: line 2100
line 2108
line 2113
line 2118
line 2156
line 2159

There is one error condition that doesn't unlock a mutex.

Fixes: cd26d1c4d1bc ("media: vb2: vb2_mmap: move lock up")
Reviewed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/media/v4l2-core/videobuf2-core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -2003,7 +2003,8 @@ int vb2_mmap(struct vb2_queue *q, struct
if (length < (vma->vm_end - vma->vm_start)) {
dprintk(1,
"MMAP invalid, as it would overflow buffer length\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}

ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);