CVE: CVE-2025-40238
Published: 2025-12-04
Description: In the Linux kernel, the following vulnerability has been resolved:

net/mlx5: Fix IPsec cleanup over MPV device

When we do mlx5e_detach_netdev() we eventually disable blocking events
notifier, among those events are IPsec MPV events from IB to core.

So before disabling those blocking events, make sure to also unregister
the devcom device and mark all this device operations as complete,
in order to prevent the other device from using invalid netdev
during future devcom events which could cause the trace below.

BUG: kernel NULL pointer dereference, address: [PII_REDACTED]
PGD 146427067 P4D 146427067 PUD 146488067 PMD 0
Oops: Oops: 0000 [#1] SMP
CPU: 1 UID: 0 PID: 7735 Comm: devlink Tainted: GW 6.12.0-rc6_for_upstream_min_debug_2024_11_08_00_46 #1
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:mlx5_devcom_comp_set_ready+0x5/0x40 [mlx5_core]
Code: 00 01 48 83 05 23 32 1e 00 01 41 b8 ed ff ff ff e9 60 ff ff ff 48 83 05 00 32 1e 00 01 eb e3 66 0f 1f 44 00 00 0f 1f 44 00 00 <48> 8b 47 10 48 83 05 5f 32 1e 00 01 48 8b 50 40 48 85 d2 74 05 40
RSP: 0018:ffff88811a5c35f8 EFLAGS: 00010206
RAX: ffff888106e8ab80 RBX: ffff888107d7e200 RCX: ffff88810d6f0a00
RDX: ffff88810d6f0a00 RSI: [PII_REDACTED] RDI: [PII_REDACTED]
RBP: ffff88811a17e620 R08: [PII_REDACTED] R09: [PII_REDACTED]
R10: ffff88811a5c3618 R11: 0000000de85d51bd R12: ffff88811a17e600
R13: ffff88810d6f0a00 R14: [PII_REDACTED] R15: ffff8881034bda80
FS:  00007f27bdf89180(0000) GS:ffff88852c880000(0000) knlGS:[PII_REDACTED]
CS:  0010 DS: 0000 ES: 0000 CR0: [PII_REDACTED]
CR2: [PII_REDACTED] CR3: 000000010f159005 CR4:[PII_REDACTED]372eb0
DR0: [PII_REDACTED] DR1: [PII_REDACTED] DR2: [PII_REDACTED]
DR3: [PII_REDACTED] DR6: 00000000fffe0ff0 DR7: [PII_REDACTED]
Call Trace:
 <TASK>
 ? __die+0x20/0x60
 ? page_fault_oops+0x150/0x3e0
 ? exc_page_fault+0x74/0x130
 ? asm_exc_page_fault+0x22/0x30
 ? mlx5_devcom_comp_set_ready+0x5/0x40 [mlx5_core]
 mlx5e_devcom_event_mpv+0x42/0x60 [mlx5_core]
 mlx5_devcom_send_event+0x8c/0x170 [mlx5_core]
 blocking_event+0x17b/0x230 [mlx5_core]
 notifier_call_chain+0x35/0xa0
 blocking_notifier_call_chain+0x3d/0x60
 mlx5_blocking_notifier_call_chain+0x22/0x30 [mlx5_core]
 mlx5_core_mp_event_replay+0x12/0x20 [mlx5_core]
 mlx5_ib_bind_slave_port+0x228/0x2c0 [mlx5_ib]
 mlx5_ib_stage_init_init+0x664/0x9d0 [mlx5_ib]
 ? idr_alloc_cyclic+0x50/0xb0
 ? __kmalloc_cache_noprof+0x167/0x340
 ? __kmalloc_noprof+0x1a7/0x430
 __mlx5_ib_add+0x34/0xd0 [mlx5_ib]
 mlx5r_probe+0xe9/0x310 [mlx5_ib]
 ? kernfs_add_one+0x107/0x150
 ? __mlx5_ib_add+0xd0/0xd0 [mlx5_ib]
 auxiliary_bus_probe+0x3e/0x90
 really_probe+0xc5/0x3a0
 ? driver_probe_device+0x90/0x90
 __driver_probe_device+0x80/0x160
 driver_probe_device+0x1e/0x90
 __device_attach_driver+0x7d/0x100
 bus_for_each_drv+0x80/0xd0
 __device_attach+0xbc/0x1f0
 bus_probe_device+0x86/0xa0
 device_add+0x62d/0x830
 __auxiliary_device_add+0x3b/0xa0
 ? auxiliary_device_init+0x41/0x90
 add_adev+0xd1/0x150 [mlx5_core]
 mlx5_rescan_drivers_locked+0x21c/0x300 [mlx5_core]
 esw_mode_change+0x6c/0xc0 [mlx5_core]
 mlx5_devlink_eswitch_mode_set+0x21e/0x640 [mlx5_core]
 devlink_nl_eswitch_set_doit+0x60/0xe0
 genl_family_rcv_msg_doit+0xd0/0x120
 genl_rcv_msg+0x180/0x2b0
 ? devlink_get_from_attrs_lock+0x170/0x170
 ? devlink_nl_eswitch_get_doit+0x290/0x290
 ? devlink_nl_pre_doit_port_optional+0x50/0x50
 ? genl_family_rcv_msg_dumpit+0xf0/0xf0
 netlink_rcv_skb+0x54/0x100
 genl_rcv+0x24/0x40
 netlink_unicast+0x1fc/0x2d0
 netlink_sendmsg+0x1e4/0x410
 __sock_sendmsg+0x38/0x60
 ? sockfd_lookup_light+0x12/0x60
 __sys_sendto+0x105/0x160
 ? __sys_recvmsg+0x4e/0x90
 __x64_sys_sendto+0x20/0x30
 do_syscall_64+0x4c/0x100
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f27bc91b13a
Code: bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 8b 05 fa 96 2c 00 45 89 c9 4c 63 d1 48 63 ff 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 
---truncated---
References: https://git.kernel.org/stable/c/664f76be38a18c61151d0ef248c7e2f3afb4f3c7; https://git.kernel.org/stable/c/7e212cebc863c2c7a82f480446cd[PII_REDACTED]91; https://git.kernel.org/stable/c/8956686d398eca6d324d2d164f9d2a281175a3a1