CVE-2024-50155 netdevsim: use cond_resched() in nsim_dev_trap_report_work()

What is CVE-2024-50155?

CVE-2024-50155 is a high-severity denial of service vulnerability in Linux kernel, published on 7 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

netdevsim: use cond_resched() in nsim_dev_trap_report_work()

I am still seeing many syzbot reports hinting that syzbot might fool nsim_dev_trap_report_work() with hundreds of ports [1]

Lets use cond_resched(), and system_unbound_wq instead of implicit system_wq.

[1] INFO: task syz-executor:20633 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:25856 pid:20633 tgid:20633 ppid:1 flags:0x00004006 ... NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 16760 Comm: kworker/1:0 Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 04 fb 9c 0c 48 89 de 5b e9 c3 c7 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 c0 d7 03 00 65 8b 15 60 f0 RSP: 0018:ffffc90000a187e8 EFLAGS: 00000246 RAX: 0000000000000100 RBX: ffffc90000a188e0 RCX: ffff888027d3bc00 RDX: ffff888027d3bc00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88804a2e6000 R08: ffffffff8a4bc495 R09: ffffffff89da3577 R10: 0000000000000004 R11: ffffffff8a4bc2b0 R12: dffffc0000000000 R13: ffff88806573b503 R14: dffffc0000000000 R15: ffff8880663cca00 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc90a747f98 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 000000000000002b DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK>

Which versions are affected by CVE-2024-50155?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-50155?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2024-50155 being exploited?

There is no known exploitation of CVE-2024-50155 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-53594, BELL-CVE-2024-50155, DEBIAN-CVE-2024-50155, GHSA-pgq2-52j2-j4xx, UBUNTU-CVE-2024-50155.