CVE-2024-41047 i40e: Fix XDP program unloading while removing the driver
A logic error in the i40e driver causes kernel warnings and potential instability when unloading the driver while an XDP program is active.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-41047?
CVE-2024-41047 is a medium-severity denial of service vulnerability in Linux kernel, published on 29 Jul 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:
i40e: Fix XDP program unloading while removing the driver
The commit 6533e558c650 ("i40e: Fix reset path while removing the driver") introduced a new PF state "__I40E_IN_REMOVE" to block modifying the XDP program while the driver is being removed. Unfortunately, such a change is useful only if the ".ndo_bpf()" callback was called out of the rmmod context because unloading the existing XDP program is also a part of driver removing procedure. In other words, from the rmmod context the driver is expected to unload the XDP program without reporting any errors. Otherwise, the kernel warning with callstack is printed out to dmesg.
Example failing scenario: 1. Load the i40e driver. 2. Load the XDP program. 3. Unload the i40e driver (using "rmmod" command).
The example kernel warning log:
[ +0.004646] WARNING: CPU: 94 PID: 10395 at net/core/dev.c:9290 unregister_netdevice_many_notify+0x7a9/0x870 [...] [ +0.010959] RIP: 0010:unregister_netdevice_many_notify+0x7a9/0x870 [...] [ +0.002726] Call Trace: [ +0.002457] <TASK> [ +0.002119] ? __warn+0x80/0x120 [ +0.003245] ? unregister_netdevice_many_notify+0x7a9/0x870 [ +0.005586] ? report_bug+0x164/0x190 [ +0.003678] ? handle_bug+0x3c/0x80 [ +0.003503] ? exc_invalid_op+0x17/0x70 [ +0.003846] ? asm_exc_invalid_op+0x1a/0x20 [ +0.004200] ? unregister_netdevice_many_notify+0x7a9/0x870 [ +0.005579] ? unregister_netdevice_many_notify+0x3cc/0x870 [ +0.005586] unregister_netdevice_queue+0xf7/0x140 [ +0.004806] unregister_netdev+0x1c/0x30 [ +0.003933] i40e_vsi_release+0x87/0x2f0 [i40e] [ +0.004604] i40e_remove+0x1a1/0x420 [i40e] [ +0.004220] pci_device_remove+0x3f/0xb0 [ +0.003943] device_release_driver_internal+0x19f/0x200 [ +0.005243] driver_detach+0x48/0x90 [ +0.003586] bus_remove_driver+0x6d/0xf0 [ +0.003939] pci_unregister_driver+0x2e/0xb0 [ +0.004278] i40e_exit_module+0x10/0x5f0 [i40e] [ +0.004570] __do_sys_delete_module.isra.0+0x197/0x310 [ +0.005153] do_syscall_64+0x85/0x170 [ +0.003684] ? syscall_exit_to_user_mode+0x69/0x220 [ +0.004886] ? do_syscall_64+0x95/0x170 [ +0.003851] ? exc_page_fault+0x7e/0x180 [ +0.003932] entry_SYSCALL_64_after_hwframe+0x71/0x79 [ +0.005064] RIP: 0033:0x7f59dc9347cb [ +0.003648] Code: 73 01 c3 48 8b 0d 65 16 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 35 16 0c 00 f7 d8 64 89 01 48 [ +0.018753] RSP: 002b:00007ffffac99048 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ +0.007577] RAX: ffffffffffffffda RBX: 0000559b9bb2f6e0 RCX: 00007f59dc9347cb [ +0.007140] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000559b9bb2f748 [ +0.007146] RBP: 00007ffffac99070 R08: 1999999999999999 R09: 0000000000000000 [ +0.007133] R10: 00007f59dc9a5ac0 R11: 0000000000000206 R12: 0000000000000000 [ +0.007141] R13: 00007ffffac992d8 R14: 0000559b9bb2f6e0 R15: 0000000000000000 [ +0.007151] </TASK> [ +0.002204] ---[ end trace 0000000000000000 ]---
Fix this by checking if the XDP program is being loaded or unloaded. Then, block only loading a new program while "__I40E_IN_REMOVE" is set. Also, move testing "__I40E_IN_REMOVE" flag to the beginning of XDP_SETUP callback to avoid unnecessary operations and checks.
Which versions are affected by CVE-2024-41047?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-41047?
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-2024-41047 being exploited?
There is no known exploitation of CVE-2024-41047 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-41047, DEBIAN-CVE-2024-41047, GHSA-j624-93rx-49pr, UBUNTU-CVE-2024-41047.