usb: gadget: Zero ffs_io_data

[ Upstream commit 508595515f4bcfe36246e4a565cf280937aeaade ]

In some cases the "Allocate & copy" block in ffs_epfile_io() is not
executed. Consequently, in such a case ffs_alloc_buffer() is never called
and struct ffs_io_data is not initialized properly. This in turn leads to
problems when ffs_free_buffer() is called at the end of ffs_epfile_io().

This patch uses kzalloc() instead of kmalloc() in the aio case and memset()
in non-aio case to properly initialize struct ffs_io_data.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[dwoo08.lee: cherry-pick linux-4.9.y stable commit d585589e5f9b to stablize f_fs]
Signed-off-by: Dongwoo Lee <dwoo08.lee@samsung.com>
Change-Id: I33ef7d5123301beb94b9d8530664d861464f4bb1

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 82a7f2a9995fb2932b3a2e41887d474a58afe5cd..59c69db43041de8c4971414a94616adfd5e1d2cb 100644 (file)
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1102,11 +1102,12 @@ static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
        ENTER();
 
        if (!is_sync_kiocb(kiocb)) {
-               p = kmalloc(sizeof(io_data), GFP_KERNEL);
+               p = kzalloc(sizeof(io_data), GFP_KERNEL);
                if (unlikely(!p))
                        return -ENOMEM;
                p->aio = true;
        } else {
+               memset(p, 0, sizeof(*p));
                p->aio = false;
        }
 
@@ -1138,11 +1139,12 @@ static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
        ENTER();
 
        if (!is_sync_kiocb(kiocb)) {
-               p = kmalloc(sizeof(io_data), GFP_KERNEL);
+               p = kzalloc(sizeof(io_data), GFP_KERNEL);
                if (unlikely(!p))
                        return -ENOMEM;
                p->aio = true;
        } else {
+               memset(p, 0, sizeof(*p));
                p->aio = false;
        }