From 7485edb2b6ca5960205c0a49bedfd09bba30e521 Mon Sep 17 00:00:00 2001
From: Yuan Can <yuancan@huawei.com>
Date: Thu, 8 Dec 2022 09:06:25 +0100
Subject: [PATCH] media: i2c: ov772x: Fix memleak in ov772x_probe()
Git-commit: 7485edb2b6ca5960205c0a49bedfd09bba30e521
Patch-mainline: v6.3-rc1
References: git-fixes

A memory leak was reported when testing ov772x with bpf mock device:

Assertionerror: unreferenced object 0xffff888109afa7a8 (size 8):  comm "python3", pid 279, jiffies 4294805921 (age 20.681s)  hex dump (first 8 bytes):    80 22 88 15 81 88 ff ff                          ."......  backtrace:    [<000000009990b438>] __kmalloc_node+0x44/0x1b0    [<000000009e32f7d7>] kvmalloc_node+0x34/0x180    [<00000000faf48134>] v4l2_ctrl_handler_init_class+0x11d/0x180 [videodev]    [<00000000da376937>] ov772x_probe+0x1c3/0x68c [ov772x]    [<000000003f0d225e>] i2c_device_probe+0x28d/0x680    [<00000000e0b6db89>] really_probe+0x17c/0x3f0    [<000000001b19fcee>] __driver_probe_device+0xe3/0x170    [<0000000048370519>] driver_probe_device+0x49/0x120    [<000000005ead07a0>] __device_attach_driver+0xf7/0x150    [<0000000043f452b8>] bus_for_each_drv+0x114/0x180    [<00000000358e5596>] __device_attach+0x1e5/0x2d0    [<0000000043f83c5d>] bus_probe_device+0x126/0x140    [<00000000ee0f3046>] device_add+0x810/0x1130    [<00000000e0278184>] i2c_new_client_device+0x359/0x4f0    [<0000000070baf34f>] of_i2c_register_device+0xf1/0x110    [<00000000a9f2159d>] of_i2c_notify+0x100/0x160
unreferenced object 0xffff888119825c00 (size 256):
  comm "python3", pid 279, jiffies 4294805921 (age 20.681s)
  hex dump (first 32 bytes):
    00 b4 a5 17 81 88 ff ff 00 5e 82 19 81 88 ff ff  .........^......
    10 5c 82 19 81 88 ff ff 10 5c 82 19 81 88 ff ff  .\.......\......
  backtrace:
    [<000000009990b438>] __kmalloc_node+0x44/0x1b0
    [<000000009e32f7d7>] kvmalloc_node+0x34/0x180
    [<0000000073d88e0b>] v4l2_ctrl_new.cold+0x19b/0x86f [videodev]
    [<00000000b1f576fb>] v4l2_ctrl_new_std+0x16f/0x210 [videodev]
    [<00000000caf7ac99>] ov772x_probe+0x1fa/0x68c [ov772x]
    [<000000003f0d225e>] i2c_device_probe+0x28d/0x680
    [<00000000e0b6db89>] really_probe+0x17c/0x3f0
    [<000000001b19fcee>] __driver_probe_device+0xe3/0x170
    [<0000000048370519>] driver_probe_device+0x49/0x120
    [<000000005ead07a0>] __device_attach_driver+0xf7/0x150
    [<0000000043f452b8>] bus_for_each_drv+0x114/0x180
    [<00000000358e5596>] __device_attach+0x1e5/0x2d0
    [<0000000043f83c5d>] bus_probe_device+0x126/0x140
    [<00000000ee0f3046>] device_add+0x810/0x1130
    [<00000000e0278184>] i2c_new_client_device+0x359/0x4f0
    [<0000000070baf34f>] of_i2c_register_device+0xf1/0x110

The reason is that if priv->hdl.error is set, ov772x_probe() jumps to the
error_mutex_destroy without doing v4l2_ctrl_handler_free(), and all
resources allocated in v4l2_ctrl_handler_init() and v4l2_ctrl_new_std()
are leaked.

Fixes: 1112babde214 ("media: i2c: Copy ov772x soc_camera sensor driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/i2c/ov772x.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
index 4189e3fc3d53..a238e63425f8 100644
--- a/drivers/media/i2c/ov772x.c
+++ b/drivers/media/i2c/ov772x.c
@@ -1462,7 +1462,7 @@ static int ov772x_probe(struct i2c_client *client)
 	priv->subdev.ctrl_handler = &priv->hdl;
 	if (priv->hdl.error) {
 		ret = priv->hdl.error;
-		goto error_mutex_destroy;
+		goto error_ctrl_free;
 	}
 
 	priv->clk = clk_get(&client->dev, NULL);
@@ -1515,7 +1515,6 @@ static int ov772x_probe(struct i2c_client *client)
 	clk_put(priv->clk);
 error_ctrl_free:
 	v4l2_ctrl_handler_free(&priv->hdl);
-error_mutex_destroy:
 	mutex_destroy(&priv->lock);
 
 	return ret;
-- 
2.35.3