[PATCH 5.4 078/434] media: vim2m: Fix BUG_ON in vim2m_device_release()

Greg Kroah-Hartman
2019-12-29T18:10:24Z

From: Kefeng Wang <wangkefeng.wang@huawei.com>

[ Upstream commit 2455d417c03aa0cbafed04c46cbb354643238318 ]

If v4l2_m2m_init() fails, m2m_dev pointer will be set ERR_PTR(-ENOMEM),
then kfree m2m_dev will trigger BUG_ON, see below, fix it by setting m2m_dev
to NULL.

vim2m vim2m.0: Failed to init mem2mem device
------------[ cut here ]------------
kernel BUG at mm/slub.c:3944!
invalid opcode: 0000 [#1] SMP PTI
CPU: 11 PID: 9061 Comm: insmod Tainted: G E 5.2.0-rc2 #81
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:kfree+0x11a/0x160

Call Trace:
vim2m_device_release+0x3f/0x50 [vim2m]
device_release+0x27/0x80
kobject_release+0x68/0x190
vim2m_probe+0x20f/0x280 [vim2m]
platform_drv_probe+0x37/0x90
really_probe+0xef/0x3d0
driver_probe_device+0x110/0x120
device_driver_attach+0x4f/0x60
__driver_attach+0x9a/0x140
? device_driver_attach+0x60/0x60
bus_for_each_dev+0x76/0xc0
? klist_add_tail+0x57/0x70
bus_add_driver+0x141/0x210
driver_register+0x5b/0xe0
vim2m_init+0x29/0x1000 [vim2m]
do_one_initcall+0x46/0x1f4
? __slab_alloc+0x1c/0x30
? kmem_cache_alloc_trace+0x167/0x1b0
do_init_module+0x5b/0x21f
load_module+0x1add/0x1fb0
? __do_sys_finit_module+0xe9/0x110
__do_sys_finit_module+0xe9/0x110
do_syscall_64+0x5b/0x1c0
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: ea6c7e34f3b2 ("media: vim2m: replace devm_kzalloc by kzalloc")
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/platform/vim2m.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index 2d79cdc130c5..e17792f837f8 100644
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -1346,6 +1346,7 @@ static int vim2m_probe(struct platform_device *pdev)
if (IS_ERR(dev->m2m_dev)) {
v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem device\n");
ret = PTR_ERR(dev->m2m_dev);
+ dev->m2m_dev = NULL;
goto error_dev;
}

--
2.20.1