a90e8608eb
Syzkaller hits a kernel WARN when the first character of the dev name
provided is NULL. Solution is to add a NULL check before calling
cdev_device_add() in vduse_create_dev().
kobject: (0000000072042169): attempted to be registered with empty name!
WARNING: CPU: 0 PID: 112695 at lib/kobject.c:236
Call Trace:
kobject_add_varg linux/src/lib/kobject.c:390 [inline]
kobject_add+0xf6/0x150 linux/src/lib/kobject.c:442
device_add+0x28f/0xc20 linux/src/drivers/base/core.c:2167
cdev_device_add+0x83/0xc0 linux/src/fs/char_dev.c:546
vduse_create_dev linux/src/drivers/vdpa/vdpa_user/vduse_dev.c:2254 [inline]
vduse_ioctl+0x7b5/0xf30 linux/src/drivers/vdpa/vdpa_user/vduse_dev.c:2316
vfs_ioctl linux/src/fs/ioctl.c:47 [inline]
file_ioctl linux/src/fs/ioctl.c:510 [inline]
do_vfs_ioctl+0x14b/0xa80 linux/src/fs/ioctl.c:697
ksys_ioctl+0x7c/0xa0 linux/src/fs/ioctl.c:714
__do_sys_ioctl linux/src/fs/ioctl.c:721 [inline]
__se_sys_ioctl linux/src/fs/ioctl.c:719 [inline]
__x64_sys_ioctl+0x42/0x50 linux/src/fs/ioctl.c:719
do_syscall_64+0x94/0x330 linux/src/arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Cc: "Xie Yongji" <xieyongji@bytedance.com>
Reported-by: Xianjun Zeng <zengxianjun@bytedance.com>
Signed-off-by: Sheng Zhao <sheng.zhao@bytedance.com>
Message-Id: <20230530033626.1266794-1-sheng.zhao@bytedance.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Cc: "Michael S. Tsirkin"<mst@redhat.com>, "Jason Wang"<jasowang@redhat.com>,
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.