CVE-2025-21708 net: usb: rtl8150: enable basic endpoint checking

What is CVE-2025-21708?

CVE-2025-21708 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Feb 2025. 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:

net: usb: rtl8150: enable basic endpoint checking

Syzkaller reports [1] encountering a common issue of utilizing a wrong usb endpoint type during URB submitting stage. This, in turn, triggers a warning shown below.

For now, enable simple endpoint checking (specifically, bulk and interrupt eps, testing control one is not essential) to mitigate the issue with a view to do other related cosmetic changes later, if they are necessary.

[1] Syzkaller report: usb 1-1: BOGUS urb xfer, pipe 3 != type 1 WARNING: CPU: 1 PID: 2586 at drivers/usb/core/urb.c:503 usb_submit_urb+0xe4b/0x1730 driv> Modules linked in: CPU: 1 UID: 0 PID: 2586 Comm: dhcpcd Not tainted 6.11.0-rc4-syzkaller-00069-gfc88bb11617> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503 Code: 84 3c 02 00 00 e8 05 e4 fc fc 4c 89 ef e8 fd 25 d7 fe 45 89 e0 89 e9 4c 89 f2 48 8> RSP: 0018:ffffc9000441f740 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888112487a00 RCX: ffffffff811a99a9 RDX: ffff88810df6ba80 RSI: ffffffff811a99b6 RDI: 0000000000000001 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff8881023bf0a8 R14: ffff888112452a20 R15: ffff888112487a7c FS: 00007fc04eea5740(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0a1de9f870 CR3: 000000010dbd0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> rtl8150_open+0x300/0xe30 drivers/net/usb/rtl8150.c:733 __dev_open+0x2d4/0x4e0 net/core/dev.c:1474 __dev_change_flags+0x561/0x720 net/core/dev.c:8838 dev_change_flags+0x8f/0x160 net/core/dev.c:8910 devinet_ioctl+0x127a/0x1f10 net/ipv4/devinet.c:1177 inet_ioctl+0x3aa/0x3f0 net/ipv4/af_inet.c:1003 sock_do_ioctl+0x116/0x280 net/socket.c:1222 sock_ioctl+0x22e/0x6c0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc04ef73d49 ...

This change has not been tested on real hardware.

Which versions are affected by CVE-2025-21708?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21708?

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-2025-21708 being exploited?

There is no known exploitation of CVE-2025-21708 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 BELL-CVE-2025-21708, DEBIAN-CVE-2025-21708, GHSA-r5rf-wpwj-h23p, ROOT-OS-UBUNTU-2404-CVE-2025-21708, UBUNTU-CVE-2025-21708.