CVE-2025-21682

Published Jan 31, 2025

Last updated 5 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: eth: bnxt: always recalculate features after XDP clearing, fix null-deref Recalculate features when XDP is detached. Before: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: off [requested on] After: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: on The fact that HW-GRO doesn't get re-enabled automatically is just a minor annoyance. The real issue is that the features will randomly come back during another reconfiguration which just happens to invoke netdev_update_features(). The driver doesn't handle reconfiguring two things at a time very robustly. Starting with commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") we only reconfigure the RSS hash table if the "effective" number of Rx rings has changed. If HW-GRO is enabled "effective" number of rings is 2x what user sees. So if we are in the bad state, with HW-GRO re-enablement "pending" after XDP off, and we lower the rings by / 2 - the HW-GRO rings doing 2x and the ethtool -L doing / 2 may cancel each other out, and the: if (old_rx_rings != bp->hw_resc.resv_rx_rings && condition in __bnxt_reserve_rings() will be false. The RSS map won't get updated, and we'll crash with: BUG: kernel NULL pointer dereference, address: 0000000000000168 RIP: 0010:__bnxt_hwrm_vnic_set_rss+0x13a/0x1a0 bnxt_hwrm_vnic_rss_cfg_p5+0x47/0x180 __bnxt_setup_vnic_p5+0x58/0x110 bnxt_init_nic+0xb72/0xf50 __bnxt_open_nic+0x40d/0xab0 bnxt_open_nic+0x2b/0x60 ethtool_set_channels+0x18c/0x1d0 As we try to access a freed ring. The issue is present since XDP support was added, really, but prior to commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") it wasn't causing major issues.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix crash on profile change rollback failure mlx5e_netdev_change_profile can fail to attach a new profile and can fail to rollback to old profile, in such case, we could end up with a dangling netdev with a fully reset netdev_priv. A retry to change profile, e.g. another attempt to call mlx5e_netdev_change_profile via switchdev mode change, will crash trying to access the now NULL priv->mdev. This fix allows mlx5e_netdev_change_profile() to handle previous failures and an empty priv, by not assuming priv is valid. Pass netdev and mdev to all flows requiring mlx5e_netdev_change_profile() and avoid passing priv. In mlx5e_netdev_change_profile() check if current priv is valid, and if not, just attach the new profile without trying to access the old one. This fixes the following oops, when enabling switchdev mode for the 2nd time after first time failure: ## Enabling switchdev mode first time: mlx5_core 0012:03:00.1: E-Switch: Supported tc chains and prios offload workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12 mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: new profile init failed, -12 workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12 mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12 ^^^^^^^^ mlx5_core 0000:00:03.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0) ## retry: Enabling switchdev mode 2nd time: mlx5_core 0000:00:03.0: E-Switch: Supported tc chains and prios offload BUG: kernel NULL pointer dereference, address: 0000000000000038 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 13 UID: 0 PID: 520 Comm: devlink Not tainted 6.18.0-rc4+ #91 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:mlx5e_detach_netdev+0x3c/0x90 Code: 50 00 00 f0 80 4f 78 02 48 8b bf e8 07 00 00 48 85 ff 74 16 48 8b 73 78 48 d1 ee 83 e6 01 83 f6 01 40 0f b6 f6 e8 c4 42 00 00 <48> 8b 45 38 48 85 c0 74 08 48 89 df e8 cc 47 40 1e 48 8b bb f0 07 RSP: 0018:ffffc90000673890 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8881036a89c0 RCX: 0000000000000000 RDX: ffff888113f63800 RSI: ffffffff822fe720 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000002dcd R09: 0000000000000000 R10: ffffc900006738e8 R11: 00000000ffffffff R12: 0000000000000000 R13: 0000000000000000 R14: ffff8881036a89c0 R15: 0000000000000000 FS: 00007fdfb8384740(0000) GS:ffff88856a9d6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 0000000112ae0005 CR4: 0000000000370ef0 Call Trace: <TASK> mlx5e_netdev_change_profile+0x45/0xb0 mlx5e_vport_rep_load+0x27b/0x2d0 mlx5_esw_offloads_rep_load+0x72/0xf0 esw_offloads_enable+0x5d0/0x970 mlx5_eswitch_enable_locked+0x349/0x430 ? is_mp_supported+0x57/0xb0 mlx5_devlink_eswitch_mode_set+0x26b/0x430 devlink_nl_eswitch_set_doit+0x6f/0xf0 genl_family_rcv_msg_doit+0xe8/0x140 genl_rcv_msg+0x18b/0x290 ? __pfx_devlink_nl_pre_doit+0x10/0x10 ? __pfx_devlink_nl_eswitch_set_doit+0x10/0x10 ? __pfx_devlink_nl_post_doit+0x10/0x10 ? __pfx_genl_rcv_msg+0x10/0x10 netlink_rcv_skb+0x52/0x100 genl_rcv+0x28/0x40 netlink_unicast+0x282/0x3e0 ? __alloc_skb+0xd6/0x190 netlink_sendmsg+0x1f7/0x430 __sys_sendto+0x213/0x220 ? __sys_recvmsg+0x6a/0xd0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x50/0x1f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fdfb8495047CVE-2026-23000