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

net/mlx5e: Fix use-after-free of encap entry in neigh update handler

Function mlx5e_rep_neigh_update() wasn't updated to accommodate rtnl lock
removal from TC filter update path and properly handle concurrent encap
entry insertion/deletion which can lead to following use-after-free:

[23827.464923] ==================================================================
[23827.469446] BUG: KASAN: use-after-free in mlx5e_encap_take+0x72/0x140 [mlx5_core]
[23827.470971] Read of size 4 at addr ffff8881d132228c by task kworker/u20:6/21635
[23827.472251]
[23827.472615] CPU: 9 PID: 21635 Comm: kworker/u20:6 Not tainted 5.13.0-rc3+ #5
[23827.473788] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[23827.475639] Workqueue: mlx5e mlx5e_rep_neigh_update [mlx5_core]
[23827.476731] Call Trace:
[23827.477260] dump_stack+0xbb/0x107
[23827.477906] print_address_description.constprop.0+0x18/0x140
[23827.478896] ? mlx5e_encap_take+0x72/0x140 [mlx5_core]
[23827.479879] ? mlx5e_encap_take+0x72/0x140 [mlx5_core]
[23827.480905] kasan_report.cold+0x7c/0xd8
[23827.481701] ? mlx5e_encap_take+0x72/0x140 [mlx5_core]
[23827.482744] kasan_check_range+0x145/0x1a0
[23827.493112] mlx5e_encap_take+0x72/0x140 [mlx5_core]
[23827.494054] ? mlx5e_tc_tun_encap_info_equal_generic+0x140/0x140 [mlx5_core]
[23827.495296] mlx5e_rep_neigh_update+0x41e/0x5e0 [mlx5_core]
[23827.496338] ? mlx5e_rep_neigh_entry_release+0xb80/0xb80 [mlx5_core]
[23827.497486] ? read_word_at_a_time+0xe/0x20
[23827.498250] ? strscpy+0xa0/0x2a0
[23827.498889] process_one_work+0x8ac/0x14e0
[23827.499638] ? lockdep_hardirqs_on_prepare+0x400/0x400
[23827.500537] ? pwq_dec_nr_in_flight+0x2c0/0x2c0
[23827.501359] ? rwlock_bug.part.0+0x90/0x90
[23827.502116] worker_thread+0x53b/0x1220
[23827.502831] ? process_one_work+0x14e0/0x14e0
[23827.503627] kthread+0x328/0x3f0
[23827.504254] ? _raw_spin_unlock_irq+0x24/0x40
[23827.505065] ? __kthread_bind_mask+0x90/0x90
[23827.505912] ret_from_fork+0x1f/0x30
[23827.506621]
[23827.506987] Allocated by task 28248:
[23827.507694] kasan_save_stack+0x1b/0x40
[23827.508476] __kasan_kmalloc+0x7c/0x90
[23827.509197] mlx5e_attach_encap+0xde1/0x1d40 [mlx5_core]
[23827.510194] mlx5e_tc_add_fdb_flow+0x397/0xc40 [mlx5_core]
[23827.511218] __mlx5e_add_fdb_flow+0x519/0xb30 [mlx5_core]
[23827.512234] mlx5e_configure_flower+0x191c/0x4870 [mlx5_core]
[23827.513298] tc_setup_cb_add+0x1d5/0x420
[23827.514023] fl_hw_replace_filter+0x382/0x6a0 [cls_flower]
[23827.514975] fl_change+0x2ceb/0x4a51 [cls_flower]
[23827.515821] tc_new_tfilter+0x89a/0x2070
[23827.516548] rtnetlink_rcv_msg+0x644/0x8c0
[23827.517300] netlink_rcv_skb+0x11d/0x340
[23827.518021] netlink_unicast+0x42b/0x700
[23827.518742] netlink_sendmsg+0x743/0xc20
[23827.519467] sock_sendmsg+0xb2/0xe0
[23827.520131] ____sys_sendmsg+0x590/0x770
[23827.520851] ___sys_sendmsg+0xd8/0x160
[23827.521552] __sys_sendmsg+0xb7/0x140
[23827.522238] do_syscall_64+0x3a/0x70
[23827.522907] entry_SYSCALL_64_after_hwframe+0x44/0xae
[23827.523797]
[23827.524163] Freed by task 25948:
[23827.524780] kasan_save_stack+0x1b/0x40
[23827.525488] kasan_set_track+0x1c/0x30
[23827.526187] kasan_set_free_info+0x20/0x30
[23827.526968] __kasan_slab_free+0xed/0x130
[23827.527709] slab_free_freelist_hook+0xcf/0x1d0
[23827.528528] kmem_cache_free_bulk+0x33a/0x6e0
[23827.529317] kfree_rcu_work+0x55f/0xb70
[23827.530024] process_one_work+0x8ac/0x14e0
[23827.530770] worker_thread+0x53b/0x1220
[23827.531480] kthread+0x328/0x3f0
[23827.532114] ret_from_fork+0x1f/0x30
[23827.532785]
[23827.533147] Last potentially related work creation:
[23827.534007] kasan_save_stack+0x1b/0x40
[23827.534710] kasan_record_aux_stack+0xab/0xc0
[23827.535492] kvfree_call_rcu+0x31/0x7b0
[23827.536206] mlx5e_tc_del
---truncated---
Published: 2024-05-21
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4178-1 linux security update
History

Fri, 14 Nov 2025 17:30:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux

Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Fri, 02 May 2025 06:30:00 +0000


Mon, 30 Dec 2024 19:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc6:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Mon, 04 Nov 2024 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Subscriptions

Debian Debian Linux
Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T13:50:48.355Z

Reserved: 2024-04-10T18:59:19.534Z

Link: CVE-2021-47247

cve-icon Vulnrichment

Updated: 2025-11-03T19:26:38.429Z

cve-icon NVD

Status : Analyzed

Published: 2024-05-21T15:15:13.703

Modified: 2025-11-14T17:16:18.063

Link: CVE-2021-47247

cve-icon Redhat

Severity : Low

Publid Date: 2024-05-21T00:00:00Z

Links: CVE-2021-47247 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses