From: Alexander Usyskin <alexander.usyskin@intel.com>
Date: Mon, 9 Jul 2018 09:21:44 +0000 (+0300)
Subject: mei: don't update offset in write
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b653d47ba52d11457397a84c32c3020c32e2c49d;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

mei: don't update offset in write

commit a103af1b64d74853a5e08ca6c86aeb0e5c6ca4f1 upstream.

MEI enables writes of complete messages only
while read can be performed in parts, hence
write should not update the file offset to
not break interleaving partial reads with writes.

Cc: <stable@vger.kernel.org>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 60f5a8ded8dd..8904491dfda4 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -304,7 +304,6 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 		goto out;
 	}
 
-	*offset = 0;
 	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
 	if (!cb) {
 		rets = -ENOMEM;