// For flags

CVE-2021-47606

net: netlink: af_netlink: Prevent empty skb by adding a check on len.

Severity Score

5.5
*CVSS v3.1

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: netlink: af_netlink: Prevent empty skb by adding a check on len. Adding a check on len parameter to avoid empty skb. This prevents a
division error in netem_enqueue function which is caused when skb->len=0
and skb->data_len=0 in the randomized corruption step as shown below. skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8); Crash Report:
[ 343.170349] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family
0 port 6081 - 0
[ 343.216110] netem: version 1.3
[ 343.235841] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 343.236680] CPU: 3 PID: 4288 Comm: reproducer Not tainted 5.16.0-rc1+
[ 343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.11.0-2.el7 04/01/2014
[ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem]
[ 343.239499] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff
ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f
74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03
[ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246
[ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX:
0000000000000000
[ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI:
ffff88800f8eda40
[ 343.244474] RBP: ffff88800bcd7458 R08: 0000000000000000 R09:
ffffffff94fb8445
[ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12:
0000000000000000
[ 343.246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15:
0000000000000020
[ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000)
knlGS:0000000000000000
[ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4:
00000000000006e0
[ 343.250076] Call Trace:
[ 343.250423] <TASK>
[ 343.250713] ? memcpy+0x4d/0x60
[ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem]
[ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem]
[ 343.253102] ? stack_trace_save+0x87/0xb0
[ 343.253655] ? filter_irq_stacks+0xb0/0xb0
[ 343.254220] ? netem_init+0xa0/0xa0 [sch_netem]
[ 343.254837] ? __kasan_check_write+0x14/0x20
[ 343.255418] ? _raw_spin_lock+0x88/0xd6
[ 343.255953] dev_qdisc_enqueue+0x50/0x180
[ 343.256508] __dev_queue_xmit+0x1a7e/0x3090
[ 343.257083] ? netdev_core_pick_tx+0x300/0x300
[ 343.257690] ? check_kcov_mode+0x10/0x40
[ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40
[ 343.258899] ? __kasan_init_slab_obj+0x24/0x30
[ 343.259529] ? setup_object.isra.71+0x23/0x90
[ 343.260121] ? new_slab+0x26e/0x4b0
[ 343.260609] ? kasan_poison+0x3a/0x50
[ 343.261118] ? kasan_unpoison+0x28/0x50
[ 343.261637] ? __kasan_slab_alloc+0x71/0x90
[ 343.262214] ? memcpy+0x4d/0x60
[ 343.262674] ? write_comp_data+0x2f/0x90
[ 343.263209] ? __kasan_check_write+0x14/0x20
[ 343.263802] ? __skb_clone+0x5d6/0x840
[ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.264958] dev_queue_xmit+0x1c/0x20
[ 343.265470] netlink_deliver_tap+0x652/0x9c0
[ 343.266067] netlink_unicast+0x5a0/0x7f0
[ 343.266608] ? netlink_attachskb+0x860/0x860
[ 343.267183] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.267820] ? write_comp_data+0x2f/0x90
[ 343.268367] netlink_sendmsg+0x922/0xe80
[ 343.268899] ? netlink_unicast+0x7f0/0x7f0
[ 343.269472] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.270099] ? write_comp_data+0x2f/0x90
[ 343.270644] ? netlink_unicast+0x7f0/0x7f0
[ 343.271210] sock_sendmsg+0x155/0x190
[ 343.271721] ____sys_sendmsg+0x75f/0x8f0
[ 343.272262] ? kernel_sendmsg+0x60/0x60
[ 343.272788] ? write_comp_data+0x2f/0x90
[ 343.273332] ? write_comp_data+0x2f/0x90
[ 343.273869] ___sys_sendmsg+0x10f/0x190
[ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80
[ 343.274984] ? slab_post_alloc_hook+0x70/0x230
[ 343.275597] ? futex_wait_setup+0x240/0x240
[ 343.276175] ? security_file_alloc+0x3e/0x170
[ 343.276779] ? write_comp_d
---truncated---

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: netlink: af_netlink: Evite el skb vacío agregando una marca en len. Agregar una verificación en el parámetro len para evitar skb vacío. Esto evita un error de división en la función netem_enqueue que se produce cuando skb-&gt;len=0 y skb-&gt;data_len=0 en el paso de corrupción aleatoria como se muestra a continuación. skb-&gt;datos[prandom_u32() % skb_headlen(skb)] ^= 1&lt;&lt;(prandom_u32() % 8); Informe de fallo: [343.170349] netdevsim netdevsim0 netdevsim3: establecer [1, 0] tipo 2 familia 0 puerto 6081 - 0 [343.216110] netem: versión 1.3 [343.235841] error de división: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 80] CPU : 3 PID: 4288 Comm: reproductor No contaminado 5.16.0-rc1+ [ 343.237569] Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 01/04/2014 [ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] [ 343.239499] Código: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff ff 8b 8d 50 ff ff 8b 85 58 ff ff 4 8 8b bd 70 y sigs. ff ff 31 d2 2b 4f 74 f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 [ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 46 [343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: 0000000000000000 [ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: ffff88800f8eda40 [ 343.244474] RBP: ff88800bcd7458 R08: 0000000000000000 R09: ffffffff94fb8445 [ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: 0000000000000000 [ 343. 246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15 : 0000000000000020 [ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) knlGS:0000000000000000 [ 343.248350] CS: 0010 DS: 000 ES: 0000 CR0: 0000000080050033 [ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: 00000000000006e0 [ 343.250076] Seguimiento de llamadas: [ 343.250423] [ 343.250713] ? memcpy+0x4d/0x60 [343.251162]? netem_init+0xa0/0xa0 [sch_netem] [ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem] [ 343.253102] ? stack_trace_save+0x87/0xb0 [343.253655]? filter_irq_stacks+0xb0/0xb0 [343.254220]? netem_init+0xa0/0xa0 [sch_netem] [ 343.254837] ? __kasan_check_write+0x14/0x20 [343.255418]? _raw_spin_lock+0x88/0xd6 [ 343.255953] dev_qdisc_enqueue+0x50/0x180 [ 343.256508] __dev_queue_xmit+0x1a7e/0x3090 [ 343.257083] ? netdev_core_pick_tx+0x300/0x300 [343.257690]? check_kcov_mode+0x10/0x40 [343.258219]? _raw_spin_unlock_irqrestore+0x29/0x40 [343.258899]? __kasan_init_slab_obj+0x24/0x30 [343.259529] ? setup_object.isra.71+0x23/0x90 [343.260121]? nueva_losa+0x26e/0x4b0 [ 343.260609] ? kasan_poison+0x3a/0x50 [ 343.261118] ? kasan_unpoison+0x28/0x50 [343.261637]? __kasan_slab_alloc+0x71/0x90 [343.262214]? memcpy+0x4d/0x60 [343.262674]? write_comp_data+0x2f/0x90 [343.263209]? __kasan_check_write+0x14/0x20 [343.263802]? __skb_clone+0x5d6/0x840 [343.264329]? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.264958] dev_queue_xmit+0x1c/0x20 [ 343.265470] netlink_deliver_tap+0x652/0x9c0 [ 343.266067] netlink_unicast+0x5a0/0x7f0 [ 343. 266608] ? netlink_attachskb+0x860/0x860 [343.267183]? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.267820] ? write_comp_data+0x2f/0x90 [343.268367] netlink_sendmsg+0x922/0xe80 [343.268899]? netlink_unicast+0x7f0/0x7f0 [343.269472]? __sanitizer_cov_trace_pc+0x21/0x60 [343.270099] ? write_comp_data+0x2f/0x90 [343.270644]? netlink_unicast+0x7f0/0x7f0 [343.271210] sock_sendmsg+0x155/0x190 [343.271721] ____sys_sendmsg+0x75f/0x8f0 [343.272262] ? kernel_sendmsg+0x60/0x60 [343.272788]? write_comp_data+0x2f/0x90 [343.273332]? write_comp_data+0x2f/0x90 [ 343.273869] ___sys_sendmsg+0x10f/0x190 [ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80 [343.274984]? slab_post_alloc_hook+0x70/0x230 [343.275597]? futex_wait_setup+0x240/0x240 [343.276175]? security_file_alloc+0x3e/0x170 [343.276779]? write_comp_d ---truncado---

In the Linux kernel, the following vulnerability has been resolved: net: netlink: af_netlink: Prevent empty skb by adding a check on len. Adding a check on len parameter to avoid empty skb. This prevents a division error in netem_enqueue function which is caused when skb->len=0 and skb->data_len=0 in the randomized corruption step as shown below. skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8); Crash Report: [ 343.170349] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0 [ 343.216110] netem: version 1.3 [ 343.235841] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 343.236680] CPU: 3 PID: 4288 Comm: reproducer Not tainted 5.16.0-rc1+ [ 343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] [ 343.239499] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f 74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 [ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 [ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: 0000000000000000 [ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: ffff88800f8eda40 [ 343.244474] RBP: ffff88800bcd7458 R08: 0000000000000000 R09: ffffffff94fb8445 [ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: 0000000000000000 [ 343.246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15: 0000000000000020 [ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) knlGS:0000000000000000 [ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: 00000000000006e0 [ 343.250076] Call Trace: [ 343.250423] <TASK> [ 343.250713] ? memcpy+0x4d/0x60 [ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem] [ 343.253102] ? stack_trace_save+0x87/0xb0 [ 343.253655] ? filter_irq_stacks+0xb0/0xb0 [ 343.254220] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.254837] ? __kasan_check_write+0x14/0x20 [ 343.255418] ? _raw_spin_lock+0x88/0xd6 [ 343.255953] dev_qdisc_enqueue+0x50/0x180 [ 343.256508] __dev_queue_xmit+0x1a7e/0x3090 [ 343.257083] ? netdev_core_pick_tx+0x300/0x300 [ 343.257690] ? check_kcov_mode+0x10/0x40 [ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40 [ 343.258899] ? __kasan_init_slab_obj+0x24/0x30 [ 343.259529] ? setup_object.isra.71+0x23/0x90 [ 343.260121] ? new_slab+0x26e/0x4b0 [ 343.260609] ? kasan_poison+0x3a/0x50 [ 343.261118] ? kasan_unpoison+0x28/0x50 [ 343.261637] ? __kasan_slab_alloc+0x71/0x90 [ 343.262214] ? memcpy+0x4d/0x60 [ 343.262674] ? write_comp_data+0x2f/0x90 [ 343.263209] ? __kasan_check_write+0x14/0x20 [ 343.263802] ? __skb_clone+0x5d6/0x840 [ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.264958] dev_queue_xmit+0x1c/0x20 [ 343.265470] netlink_deliver_tap+0x652/0x9c0 [ 343.266067] netlink_unicast+0x5a0/0x7f0 [ 343.266608] ? netlink_attachskb+0x860/0x860 [ 343.267183] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.267820] ? write_comp_data+0x2f/0x90 [ 343.268367] netlink_sendmsg+0x922/0xe80 [ 343.268899] ? netlink_unicast+0x7f0/0x7f0 [ 343.269472] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.270099] ? write_comp_data+0x2f/0x90 [ 343.270644] ? netlink_unicast+0x7f0/0x7f0 [ 343.271210] sock_sendmsg+0x155/0x190 [ 343.271721] ____sys_sendmsg+0x75f/0x8f0 [ 343.272262] ? kernel_sendmsg+0x60/0x60 [ 343.272788] ? write_comp_data+0x2f/0x90 [ 343.273332] ? write_comp_data+0x2f/0x90 [ 343.273869] ___sys_sendmsg+0x10f/0x190 [ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80 [ 343.274984] ? slab_post_alloc_hook+0x70/0x230 [ 343.275597] ? futex_wait_setup+0x240/0x240 [ 343.276175] ? security_file_alloc+0x3e/0x170 [ 343.276779] ? write_comp_d ---truncated---

Attila Szász discovered that the HFS+ file system implementation in the Linux Kernel contained a heap overflow vulnerability. An attacker could use a specially crafted file system image that, when mounted, could cause a denial of service or possibly execute arbitrary code. Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-24 CVE Reserved
  • 2024-06-19 CVE Published
  • 2024-12-19 CVE Updated
  • 2025-03-18 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-369: Divide By Zero
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"
< 4.4.296
Search vendor "Linux" for product "Linux Kernel" and version " < 4.4.296"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 4.9.294
Search vendor "Linux" for product "Linux Kernel" and version " < 4.9.294"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 4.14.259
Search vendor "Linux" for product "Linux Kernel" and version " < 4.14.259"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 4.19.222
Search vendor "Linux" for product "Linux Kernel" and version " < 4.19.222"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.4.167
Search vendor "Linux" for product "Linux Kernel" and version " < 5.4.167"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.10.87
Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.87"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.15.10
Search vendor "Linux" for product "Linux Kernel" and version " < 5.15.10"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.16
Search vendor "Linux" for product "Linux Kernel" and version " < 5.16"
en
Affected