On Mon, Apr 14, 2025 at 03:11:23PM +0800, Lizhi Xu wrote: > syzbot reported a uaf in software_node_notify_remove. [1] > > When any of the two sysfs_create_link() in software_node_notify() fails, > the swnode->kobj reference count will not increase normally, which will > cause swnode to be released incorrectly due to the imbalance of kobj reference > count when executing software_node_notify_remove(). > > Increase the reference count of kobj before creating the link to avoid uaf. > > [1] > BUG: KASAN: slab-use-after-free in software_node_notify_remove+0x1bc/0x1c0 drivers/base/swnode.c:1108 > Read of size 1 at addr ffff888033c08908 by task syz-executor105/5844 > Freed by task 5844: > software_node_notify_remove+0x159/0x1c0 drivers/base/swnode.c:1106 > device_platform_notify_remove drivers/base/core.c:2387 [inline] The fix looks correct to me, Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> -- With Best Regards, Andy Shevchenko
