From: Kefeng Wang wangkefeng.wang@huawei.com
[ Upstream commit 69fbb3f47327d959830c94bf31893972b8c8f700 ]
X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected The fm_v4l2_init_video_device() forget to unregister v4l2/video device in the error path, it could lead to UAF issue, eg,
BUG: KASAN: use-after-free in atomic64_read include/asm-generic/atomic-instrumented.h:836 [inline] BUG: KASAN: use-after-free in atomic_long_read include/asm-generic/atomic-long.h:28 [inline] BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0x92/0x690 kernel/locking/mutex.c:1206 Read of size 8 at addr ffff8881e84a7c70 by task v4l_id/3659
CPU: 1 PID: 3659 Comm: v4l_id Not tainted 5.1.0 #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xa9/0x10e lib/dump_stack.c:113 print_address_description+0x65/0x270 mm/kasan/report.c:187 kasan_report+0x149/0x18d mm/kasan/report.c:317 atomic64_read include/asm-generic/atomic-instrumented.h:836 [inline] atomic_long_read include/asm-generic/atomic-long.h:28 [inline] __mutex_unlock_slowpath+0x92/0x690 kernel/locking/mutex.c:1206 fm_v4l2_fops_open+0xac/0x120 [fm_drv] v4l2_open+0x191/0x390 [videodev] chrdev_open+0x20d/0x570 fs/char_dev.c:417 do_dentry_open+0x700/0xf30 fs/open.c:777 do_last fs/namei.c:3416 [inline] path_openat+0x7c4/0x2a90 fs/namei.c:3532 do_filp_open+0x1a5/0x2b0 fs/namei.c:3563 do_sys_open+0x302/0x490 fs/open.c:1069 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f8180c17c8e ... Allocated by task 3642: set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:497 fm_drv_init+0x13/0x1000 [fm_drv] do_one_initcall+0xbc/0x47d init/main.c:901 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 3642: set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:459 slab_free_hook mm/slub.c:1429 [inline] slab_free_freelist_hook mm/slub.c:1456 [inline] slab_free mm/slub.c:3003 [inline] kfree+0xe1/0x270 mm/slub.c:3958 fm_drv_init+0x1e6/0x1000 [fm_drv] do_one_initcall+0xbc/0x47d init/main.c:901 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Add relevant unregister functions to fix it.
Cc: Hans Verkuil hans.verkuil@cisco.com Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/radio/wl128x/fmdrv_v4l2.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/media/radio/wl128x/fmdrv_v4l2.c b/drivers/media/radio/wl128x/fmdrv_v4l2.c index dccdf6558e6a..33abc8616ecb 100644 --- a/drivers/media/radio/wl128x/fmdrv_v4l2.c +++ b/drivers/media/radio/wl128x/fmdrv_v4l2.c @@ -549,6 +549,7 @@ int fm_v4l2_init_video_device(struct fmdev *fmdev, int radio_nr)
/* Register with V4L2 subsystem as RADIO device */ if (video_register_device(&gradio_dev, VFL_TYPE_RADIO, radio_nr)) { + v4l2_device_unregister(&fmdev->v4l2_dev); fmerr("Could not register video device\n"); return -ENOMEM; } @@ -562,6 +563,8 @@ int fm_v4l2_init_video_device(struct fmdev *fmdev, int radio_nr) if (ret < 0) { fmerr("(fmdev): Can't init ctrl handler\n"); v4l2_ctrl_handler_free(&fmdev->ctrl_handler); + video_unregister_device(fmdev->radio_dev); + v4l2_device_unregister(&fmdev->v4l2_dev); return -EBUSY; }