// For flags

CVE-2021-47247

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

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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---

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net/mlx5e: se corrigió el use after free de la entrada encap en el controlador de actualización cercano. La función mlx5e_rep_neigh_update() no se actualizó para permitir la eliminación del bloqueo rtnl de la ruta de actualización del filtro TC y manejar adecuadamente inserción/eliminación simultánea de entradas encapsuladas que pueden conducir al siguiente use after free: [23827.464923] ================================ ==================================== [23827.469446] BUG: KASAN: use after free en mlx5e_encap_take +0x72/0x140 [mlx5_core] [23827.470971] Lectura de tamaño 4 en la dirección ffff8881d132228c por tarea kworker/u20:6/21635 [23827.472251] [23827.472615] CPU: 9 PID: 21635 kworker/u20 :6 No contaminado 5.13.0 -rc3+ #5 [23827.473788] Nombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 01/04/2014 [23827.475639] Cola de trabajo: mlx5e mlx5e_rep_neigh_update [ mlx5_core] [23827.476731] Seguimiento de llamadas: [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] Asignado por tarea 28248: [23827.507694] 0 [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] 191c/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 [23827.51 7300] 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] Liberado por la tarea 25948: [23827.524780] kasan_save_stack+0x1b/0x40 [23827.525488] kasan_set_track+0x1c/0x30 [23827.526187] _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 ] work_thread+0x53b/0x1220 [23827.531480] kthread+0x328/0x3f0 [23827.532114] ret_from_fork+0x1f/ 0x30 [23827.532785] [23827.533147] Última creación de trabajo potencialmente relacionado: [23827.534007] kasan_save_stack+0x1b/0x40 [23827.534710] kasan_record_aux_stack+0xab/0xc0 [23827.535492] _rcu+0x31/0x7b0 [23827.536206] mlx5e_tc_del ---truncado---

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-04-10 CVE Reserved
  • 2024-05-21 CVE Published
  • 2024-05-22 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.4 < 5.12.13
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.12.13"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.4 < 5.13
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.13"
en
Affected