CVE-2024-40995CVE-2024-40995

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc() syzbot found hanging tasks waiting on rtnl_lock [1] A reproducer is available in the syzbot bug. When a request to add multiple actions with the same index is sent, the second request will block forever on the first request. This holds rtnl_lock, and causes tasks to hang. Return -EAGAIN to prevent infinite looping, while keeping documented behavior. [1] INFO: task kworker/1:0:5088 blocked for more than 143 seconds. Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] sch