From a90e8608eb0ed93d31ac0feb055f77ce59512542 Mon Sep 17 00:00:00 2001 From: Sheng Zhao Date: Tue, 30 May 2023 11:36:26 +0800 Subject: [PATCH] vduse: avoid empty string for dev name 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" Reported-by: Xianjun Zeng Signed-off-by: Sheng Zhao Message-Id: <20230530033626.1266794-1-sheng.zhao@bytedance.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Reviewed-by: Xie Yongji Cc: "Michael S. Tsirkin", "Jason Wang", Reviewed-by: Xie Yongji --- 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 de97e38c3b82..5f5c21674fdc 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -1685,6 +1685,9 @@ 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; -- 2.11.0