From: Sheng Zhao sheng.zhao@bytedance.com
[ Upstream commit a90e8608eb0ed93d31ac0feb055f77ce59512542 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vdpa/vdpa_user/vduse_dev.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 3467c75f310a5..30ae4237f3dd4 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -1254,6 +1254,9 @@ static bool vduse_validate_config(struct vduse_dev_config *config) if (config->vq_num > 0xffff) return false;
+ if (!config->name[0]) + return false; + if (!device_is_allowed(config->device_id)) return false;