Description
In the Linux kernel, the following vulnerability has been resolved:

net: openvswitch: Avoid releasing netdev before teardown completes

The patch cited in the Fixes tag below changed the teardown code for
OVS ports to no longer unconditionally take the RTNL. After this change,
the netdev_destroy() callback can proceed immediately to the call_rcu()
invocation if the IFF_OVS_DATAPATH flag is already cleared on the
netdev.

The ovs_netdev_detach_dev() function clears the flag before completing
the unregistration, and if it gets preempted after clearing the flag (as
can happen on an -rt kernel), netdev_destroy() can complete and the
device can be freed before the unregistration completes. This leads to a
splat like:

[ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI
[ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT
[ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025
[ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0
[ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90
[ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246
[ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000
[ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05
[ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000
[ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006
[ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000
[ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000
[ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0
[ 998.393944] PKRU: 55555554
[ 998.393946] Call Trace:
[ 998.393949] <TASK>
[ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0
[ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0
[ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch]
[ 998.394009] ? __die_body.cold+0x8/0x12
[ 998.394016] ? die_addr+0x3c/0x60
[ 998.394027] ? exc_general_protection+0x16d/0x390
[ 998.394042] ? asm_exc_general_protection+0x26/0x30
[ 998.394058] ? dev_set_promiscuity+0x8d/0xa0
[ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch]
[ 998.394092] dp_device_event+0x41/0x80 [openvswitch]
[ 998.394102] notifier_call_chain+0x5a/0xd0
[ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60
[ 998.394110] rtnl_dellink+0x169/0x3e0
[ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0
[ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0
[ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0
[ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[ 998.394132] netlink_rcv_skb+0x50/0x100
[ 998.394138] netlink_unicast+0x292/0x3f0
[ 998.394141] netlink_sendmsg+0x21b/0x470
[ 998.394145] ____sys_sendmsg+0x39d/0x3d0
[ 998.394149] ___sys_sendmsg+0x9a/0xe0
[ 998.394156] __sys_sendmsg+0x7a/0xd0
[ 998.394160] do_syscall_64+0x7f/0x170
[ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 998.394165] RIP: 0033:0x7fad61bf4724
[ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
[ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724
[ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003
[ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f
[ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2
---truncated---
Published: 2026-04-22
Score: 7.0 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

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Advisories

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History

Thu, 23 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Wed, 22 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: Avoid releasing netdev before teardown completes The patch cited in the Fixes tag below changed the teardown code for OVS ports to no longer unconditionally take the RTNL. After this change, the netdev_destroy() callback can proceed immediately to the call_rcu() invocation if the IFF_OVS_DATAPATH flag is already cleared on the netdev. The ovs_netdev_detach_dev() function clears the flag before completing the unregistration, and if it gets preempted after clearing the flag (as can happen on an -rt kernel), netdev_destroy() can complete and the device can be freed before the unregistration completes. This leads to a splat like: [ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI [ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT [ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025 [ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0 [ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90 [ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246 [ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000 [ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05 [ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000 [ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006 [ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000 [ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000 [ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0 [ 998.393944] PKRU: 55555554 [ 998.393946] Call Trace: [ 998.393949] <TASK> [ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch] [ 998.394009] ? __die_body.cold+0x8/0x12 [ 998.394016] ? die_addr+0x3c/0x60 [ 998.394027] ? exc_general_protection+0x16d/0x390 [ 998.394042] ? asm_exc_general_protection+0x26/0x30 [ 998.394058] ? dev_set_promiscuity+0x8d/0xa0 [ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch] [ 998.394092] dp_device_event+0x41/0x80 [openvswitch] [ 998.394102] notifier_call_chain+0x5a/0xd0 [ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60 [ 998.394110] rtnl_dellink+0x169/0x3e0 [ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0 [ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0 [ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0 [ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 998.394132] netlink_rcv_skb+0x50/0x100 [ 998.394138] netlink_unicast+0x292/0x3f0 [ 998.394141] netlink_sendmsg+0x21b/0x470 [ 998.394145] ____sys_sendmsg+0x39d/0x3d0 [ 998.394149] ___sys_sendmsg+0x9a/0xe0 [ 998.394156] __sys_sendmsg+0x7a/0xd0 [ 998.394160] do_syscall_64+0x7f/0x170 [ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 998.394165] RIP: 0033:0x7fad61bf4724 [ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 [ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724 [ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003 [ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f [ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2 ---truncated---
Title net: openvswitch: Avoid releasing netdev before teardown completes
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-04-22T13:54:26.599Z

Reserved: 2026-03-09T15:48:24.106Z

Link: CVE-2026-31508

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-22T14:16:49.727

Modified: 2026-04-23T16:17:41.280

Link: CVE-2026-31508

cve-icon Redhat

Severity : Important

Publid Date: 2026-04-22T00:00:00Z

Links: CVE-2026-31508 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-22T18:45:23Z

Weaknesses

No weakness.