CVE-2025-38020 net/mlx5e: Disable MACsec offload for uplink representor profile
In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: Disable MACsec offload for uplink representor profile

MACsec offload is not supported in switchdev mode for uplink
representors. When switching to the uplink representor profile, the
MACsec offload feature must be cleared from the netdevice's features.

If left enabled, attempts to add offloads result in a null pointer
dereference, as the uplink representor does not support MACsec offload
even though the feature bit remains set.

Clear NETIF_F_HW_MACSEC in mlx5e_fix_uplink_rep_features().

Kernel log:

Oops: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f]
CPU: 29 UID: 0 PID: 4714 Comm: ip Not tainted 6.14.0-rc4_for_upstream_debug_2025_03_02_17_35 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:__mutex_lock+0x128/0x1dd0
Code: d0 7c 08 84 d2 0f 85 ad 15 00 00 8b 35 91 5c fe 03 85 f6 75 29 49 8d 7e 60 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a6 15 00 00 4d 3b 76 60 0f 85 fd 0b 00 00 65 ff
RSP: 0018:ffff888147a4f160 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 000000000000000f RSI: 0000000000000000 RDI: 0000000000000078
RBP: ffff888147a4f2e0 R08: ffffffffa05d2c19 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000018 R15: ffff888152de0000
FS:  00007f855e27d800(0000) GS:ffff88881ee80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004e5768 CR3: 000000013ae7c005 CR4: 0000000000372eb0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? die_addr+0x3d/0xa0
 ? exc_general_protection+0x144/0x220
 ? asm_exc_general_protection+0x22/0x30
 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core]
 ? __mutex_lock+0x128/0x1dd0
 ? lockdep_set_lock_cmp_fn+0x190/0x190
 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core]
 ? mutex_lock_io_nested+0x1ae0/0x1ae0
 ? lock_acquire+0x1c2/0x530
 ? macsec_upd_offload+0x145/0x380
 ? lockdep_hardirqs_on_prepare+0x400/0x400
 ? kasan_save_stack+0x30/0x40
 ? kasan_save_stack+0x20/0x40
 ? kasan_save_track+0x10/0x30
 ? __kasan_kmalloc+0x77/0x90
 ? __kmalloc_noprof+0x249/0x6b0
 ? genl_family_rcv_msg_attrs_parse.constprop.0+0xb5/0x240
 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core]
 mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core]
 ? mlx5e_macsec_add_rxsa+0x11a0/0x11a0 [mlx5_core]
 macsec_update_offload+0x26c/0x820
 ? macsec_set_mac_address+0x4b0/0x4b0
 ? lockdep_hardirqs_on_prepare+0x284/0x400
 ? _raw_spin_unlock_irqrestore+0x47/0x50
 macsec_upd_offload+0x2c8/0x380
 ? macsec_update_offload+0x820/0x820
 ? __nla_parse+0x22/0x30
 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x15e/0x240
 genl_family_rcv_msg_doit+0x1cc/0x2a0
 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240
 ? cap_capable+0xd4/0x330
 genl_rcv_msg+0x3ea/0x670
 ? genl_family_rcv_msg_dumpit+0x2a0/0x2a0
 ? lockdep_set_lock_cmp_fn+0x190/0x190
 ? macsec_update_offload+0x820/0x820
 netlink_rcv_skb+0x12b/0x390
 ? genl_family_rcv_msg_dumpit+0x2a0/0x2a0
 ? netlink_ack+0xd80/0xd80
 ? rwsem_down_read_slowpath+0xf90/0xf90
 ? netlink_deliver_tap+0xcd/0xac0
 ? netlink_deliver_tap+0x155/0xac0
 ? _copy_from_iter+0x1bb/0x12c0
 genl_rcv+0x24/0x40
 netlink_unicast+0x440/0x700
 ? netlink_attachskb+0x760/0x760
 ? lock_acquire+0x1c2/0x530
 ? __might_fault+0xbb/0x170
 netlink_sendmsg+0x749/0xc10
 ? netlink_unicast+0x700/0x700
 ? __might_fault+0xbb/0x170
 ? netlink_unicast+0x700/0x700
 __sock_sendmsg+0xc5/0x190
 ____sys_sendmsg+0x53f/0x760
 ? import_iovec+0x7/0x10
 ? kernel_sendmsg+0x30/0x30
 ? __copy_msghdr+0x3c0/0x3c0
 ? filter_irq_stacks+0x90/0x90
 ? stack_depot_save_flags+0x28/0xa30
 ___sys_sen
---truncated---
CVSS v3.1 score: 5.5