Subject: CVE-2024-41047: i40e: Fix XDP program unloading while removing the driver

From: Greg Kroah-Hartman <[email-masked]>

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.

The Linux kernel CVE team has assigned CVE-2024-41047 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 5.15.20 with commit b82364abc54b and fixed in 5.15.163 with commit b399a68054df
	Issue introduced in 5.17 with commit 6533e558c650 and fixed in 6.1.100 with commit 4bc336b2345f
	Issue introduced in 5.17 with commit 6533e558c650 and fixed in 6.6.41 with commit 5266302cb2c7
	Issue introduced in 5.17 with commit 6533e558c650 and fixed in 6.9.10 with commit 0075b8c94d76
	Issue introduced in 5.17 with commit 6533e558c650 and fixed in 6.10 with commit 01fc5142ae6b
	Issue introduced in 5.16.6 with commit 2754d83160c9

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-41047
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/intel/i40e/i40e_main.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/b399a68054dfb36eed121846ef5fcddba40b7740
	https://git.kernel.org/stable/c/4bc336b2345f1485438c0eb7246d9c8a8d09f8ff
	https://git.kernel.org/stable/c/5266302cb2c74d8ab0e9a69d5752fffaea70496e
	https://git.kernel.org/stable/c/0075b8c94d76830c7b6f018f6e4eeb0bf6465fdc
	https://git.kernel.org/stable/c/01fc5142ae6b06b61ed51a624f2732d6525d8ea3