CVE-2021-46955
openvswitch: fix stack OOB read while fragmenting IPv4 packets
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
openvswitch: fix stack OOB read while fragmenting IPv4 packets
running openvswitch on kernels built with KASAN, it's possible to see the
following splat while testing fragmentation of IPv4 packets:
BUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60
Read of size 1 at addr ffff888112fc713c by task handler2/1367
CPU: 0 PID: 1367 Comm: handler2 Not tainted 5.12.0-rc6+ #418
Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
Call Trace:
dump_stack+0x92/0xc1
print_address_description.constprop.7+0x1a/0x150
kasan_report.cold.13+0x7f/0x111
ip_do_fragment+0x1b03/0x1f60
ovs_fragment+0x5bf/0x840 [openvswitch]
do_execute_actions+0x1bd5/0x2400 [openvswitch]
ovs_execute_actions+0xc8/0x3d0 [openvswitch]
ovs_packet_cmd_execute+0xa39/0x1150 [openvswitch]
genl_family_rcv_msg_doit.isra.15+0x227/0x2d0
genl_rcv_msg+0x287/0x490
netlink_rcv_skb+0x120/0x380
genl_rcv+0x24/0x40
netlink_unicast+0x439/0x630
netlink_sendmsg+0x719/0xbf0
sock_sendmsg+0xe2/0x110
____sys_sendmsg+0x5ba/0x890
___sys_sendmsg+0xe9/0x160
__sys_sendmsg+0xd3/0x170
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f957079db07
Code: c3 66 90 41 54 41 89 d4 55 48 89 f5 53 89 fb 48 83 ec 10 e8 eb ec ff ff 44 89 e2 48 89 ee 89 df 41 89 c0 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 48 89 44 24 08 e8 24 ed ff ff 48
RSP: 002b:00007f956ce35a50 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000019 RCX: 00007f957079db07
RDX: 0000000000000000 RSI: 00007f956ce35ae0 RDI: 0000000000000019
RBP: 00007f956ce35ae0 R08: 0000000000000000 R09: 00007f9558006730
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f956ce37308 R14: 00007f956ce35f80 R15: 00007f956ce35ae0
The buggy address belongs to the page:
page:00000000af2a1d93 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112fc7
flags: 0x17ffffc0000000()
raw: 0017ffffc0000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
addr ffff888112fc713c is located in stack of task handler2/1367 at offset 180 in frame:
ovs_fragment+0x0/0x840 [openvswitch]
this frame has 2 objects:
[32, 144) 'ovs_dst'
[192, 424) 'ovs_rt'
Memory state around the buggy address:
ffff888112fc7000: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888112fc7080: 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00 00
>ffff888112fc7100: 00 00 00 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00
^
ffff888112fc7180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888112fc7200: 00 00 00 00 00 00 f2 f2 f2 00 00 00 00 00 00 00
for IPv4 packets, ovs_fragment() uses a temporary struct dst_entry. Then,
in the following call graph:
ip_do_fragment()
ip_skb_dst_mtu()
ip_dst_mtu_maybe_forward()
ip_mtu_locked()
the pointer to struct dst_entry is used as pointer to struct rtable: this
turns the access to struct members like rt_mtu_locked into an OOB read in
the stack. Fix this changing the temporary variable used for IPv4 packets
in ovs_fragment(), similarly to what is done for IPv6 few lines below.
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: openvswitch: corrige la lectura OOB de la pila al fragmentar paquetes IPv4 al ejecutar openvswitch en kernels creados con KASAN, es posible ver el siguiente símbolo al probar la fragmentación de paquetes IPv4: ERROR: KASAN: stack- fuera de los límites en ip_do_fragment+0x1b03/0x1f60 Lectura de tamaño 1 en la dirección ffff888112fc713c por task handler2/1367 CPU: 0 PID: 1367 Comm: handler2 Not tainted 5.12.0-rc6+ #418 Nombre de hardware: Red Hat KVM, BIOS 1.11 .1-4.module+el8.1.0+4066+0f1aadab 01/04/2014 Seguimiento de llamadas: dump_stack+0x92/0xc1 print_address_description.constprop.7+0x1a/0x150 kasan_report.cold.13+0x7f/0x111 ip_do_fragment+0x1b03/0x1f60 ovs_fragment+0x5bf/0x840 [openvswitch] do_execute_actions+0x1bd5/0x2400 [openvswitch] ovs_execute_actions+0xc8/0x3d0 [openvswitch] ovs_packet_cmd_execute+0xa39/0x1150 [openvswitch] genl_family_rcv_msg_do it.isra.15+0x227/0x2d0 genl_rcv_msg+0x287/0x490 netlink_rcv_skb+0x120/ 0x380 genl_rcv+0x24/0x40 netlink_unicast+0x439/0x630 netlink_sendmsg+0x719/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5ba/0x890 ___sys_sendmsg+0xe9/0x160 __sy s_sendmsg+0xd3/0x170 do_syscall_64+0x33/0x40 Entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033: 0x7f957079db07 Código: c3 66 90 41 54 41 89 d4 55 48 89 f5 53 89 fb 48 83 ec 10 e8 eb ec ff ff 44 89 e2 48 89 ee 89 df 41 89 c0 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 48 89 44 24 08 e8 24 ed ff ff 48 RSP: 002b:00007f956ce35a50 EFLAGS: 00000293 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RB X: 0000000000000019 RCX: 00007f957079db07 RDX: 0000000000000000 RSI: 00007f956ce35ae0 RDI: 0000000000000019 RBP: 00007f956ce35ae0 R08: 00000000000000000 R09: 00007f9558006730 R10: 0000000000000000 R11: 00000000000000293 R12: 0000000000000000 R13: 00007f956ce37308 R14: 00007f956ce35f80 R15: 00007f956ce35ae0 La dirección del error pertenece a la página: página:00000000af2a1d93 refcount:0 mapcount:0 mapeo:00000000000000000 index:0x0 pfn: 0x112fc7 banderas: 0x17ffffc0000000() sin formato: 0017ffffc0000000 0000000000000000 muerto000000000122 00000000000000000 sin formato: 0000000000000000 000000000000 0000 00000000ffffffff 0000000000000000 página volcada porque: kasan: mal acceso detectado addr ffff888112fc713c está ubicado en la pila del controlador de tareas 2/1367 en el desplazamiento 180 en el framework: ovs_fragment+0x0/0x840 [ openvswitch] este framework tiene 2 objetos: [32, 144) 'ovs_dst' [192, 424) 'ovs_rt' Estado de la memoria alrededor de la dirección del error: ffff888112fc7000: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811 2fc7080 : 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00 00 >ffff888112fc7100: 00 00 00 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 ^ ffff888112fc7180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888112fc7200: 00 00 00 00 00 00 f2 f2 f2 00 00 00 00 00 00 00 para paquetes IPv4, ovs_fragment() utiliza una estructura temporal dst_entry. Luego, en el siguiente gráfico de llamadas: ip_do_fragment() ip_skb_dst_mtu() ip_dst_mtu_maybe_forward() ip_mtu_locked() el puntero a struct dst_entry se usa como puntero a struct rtable: esto convierte el acceso a miembros de estructura como rt_mtu_locked en una lectura OOB en la pila. Solucione este problema cambiando la variable temporal utilizada para los paquetes IPv4 en ovs_fragment(), de manera similar a lo que se hace para IPv6 unas líneas más abajo.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-02-27 CVE Reserved
- 2024-02-27 CVE Published
- 2024-02-28 EPSS Updated
- 2024-08-04 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (14)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/119bbaa6795a4f4aed46994cc7d9ab01989c87e3 | Vuln. Introduced | |
| https://git.kernel.org/stable/c/d543907a4730400f5c5b684c57cb5bbbfd6136ab | Vuln. Introduced | |
| https://git.kernel.org/stable/c/8387fbac8e18e26a60559adc63e0b7067303b0a4 | Vuln. Introduced | |
| https://git.kernel.org/stable/c/d52e5a7e7ca49457dd31fc8b42fb7c0d58a31221 | Vuln. Introduced | |
| https://git.kernel.org/stable/c/df9ece1148e2ec242871623dedb004f7a1387125 | Vuln. Introduced |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|
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" | >= 4.4.134 < 4.4.269 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.4.134 < 4.4.269" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.9.104 < 4.9.269 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.9.104 < 4.9.269" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.14.45 < 4.14.233 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.14.45 < 4.14.233" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.16 < 4.19.191 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 4.19.191" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.16 < 5.4.118 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.4.118" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.16 < 5.10.36 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.10.36" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.16 < 5.11.20 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.11.20" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.16 < 5.12.3 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.12.3" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.16 < 5.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.13" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 3.16.57 Search vendor "Linux" for product "Linux Kernel" and version "3.16.57" | en |
Affected
| ||||||