CVE-2021-47419

net/sched: sch_taprio: properly cancel timer from taprio_destroy()

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

net/sched: sch_taprio: properly cancel timer from taprio_destroy()

There is a comment in qdisc_create() about us not calling ops->reset()
in some cases.

err_out4:
/*
* Any broken qdiscs that would require a ops->reset() here?
* The qdisc was never in action so it shouldn't be necessary.
*/

As taprio sets a timer before actually receiving a packet, we need
to cancel it from ops->destroy, just in case ops->reset has not
been called.

syzbot reported:

ODEBUG: free active (active state 0) object type: hrtimer hint: advance_sched+0x0/0x9a0 arch/x86/include/asm/atomic64_64.h:22
WARNING: CPU: 0 PID: 8441 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Modules linked in:
CPU: 0 PID: 8441 Comm: syz-executor813 Not tainted 5.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd e0 d3 e3 89 4c 89 ee 48 c7 c7 e0 c7 e3 89 e8 5b 86 11 05 <0f> 0b 83 05 85 03 92 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3
RSP: 0018:ffffc9000130f330 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff88802baeb880 RSI: ffffffff815d87b5 RDI: fffff52000261e58
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815d25ee R11: 0000000000000000 R12: ffffffff898dd020
R13: ffffffff89e3ce20 R14: ffffffff81653630 R15: dffffc0000000000
FS: 0000000000f0d300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb64b3e000 CR3: 0000000036557000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__debug_check_no_obj_freed lib/debugobjects.c:987 [inline]
debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1018
slab_free_hook mm/slub.c:1603 [inline]
slab_free_freelist_hook+0x171/0x240 mm/slub.c:1653
slab_free mm/slub.c:3213 [inline]
kfree+0xe4/0x540 mm/slub.c:4267
qdisc_create+0xbcf/0x1320 net/sched/sch_api.c:1299
tc_modify_qdisc+0x4c8/0x1a60 net/sched/sch_api.c:1663
rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
____sys_sendmsg+0x6e8/0x810 net/socket.c:2403
___sys_sendmsg+0xf3/0x170 net/socket.c:2457
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/sched: sch_taprio: cancelar correctamente el temporizador de taprio_destroy(). Hay un comentario en qdisc_create() acerca de que no llamamos a ops->reset() en algunos casos. err_out4: /* * ¿Alguna qdisc rota que requiera un ops->reset() aquí? * La qdisc nunca estuvo en acción por lo que no debería ser necesaria. */ Como taprio establece un temporizador antes de recibir un paquete, debemos cancelarlo desde ops->destroy, en caso de que no se haya llamado a ops->reset. syzbot informó: ODEBUG: libre activo (estado activo 0) tipo de objeto: hrtimer sugerencia: advanced_sched+0x0/0x9a0 arch/x86/include/asm/atomic64_64.h:22 ADVERTENCIA: CPU: 0 PID: 8441 en lib/debugobjects.c :505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Módulos vinculados en: CPU: 0 PID: 8441 Comm: syz-executor813 No contaminado 5.14.0-rc6-syzkaller #0 Nombre del hardware: Google Google Compute Engine/Google Compute Motor, BIOS Google 01/01/2011 RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Código: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd e0 d3 e3 89 4c 89 ee 48 c7 c7 e0 c7 e3 89 e8 5b 86 11 05 <0f> 0b 83 05 85 03 92 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 RSP 0018:ffff c9000130f330 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 00000000000000003 RCX: 0000000000000000 RDX: ffff88802baeb880 RSI: ffffffff815d87b5 RDI: fffff52000261e58 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815d25ee R11: 00000000000000000 R12: ffffffff898dd020 R13: 3ce20 R14: ffffffff81653630 R15: dffffc0000000000 FS: 0000000000f0d300( 0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffb64b3e000 CR3: 557000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 7: 0000000000000400 Seguimiento de llamadas: __debug_check_no_obj_freed lib/debugobjects.c:987 [en línea] debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1018 slab_free_hook mm/slub.c:1603 [en línea] slab_free_freelist_hook+0x171/0x240 mm/ slub.c:1653 slab_libre mm/slub.c:3213 [en línea] kfree+0xe4/0x540 mm/slub.c:4267 qdisc_create+0xbcf/0x1320 net/sched/sch_api.c:1299 tc_modify_qdisc+0x4c8/0x1a60 net/sched/sch_api.c:1663 rtnetlink_rcv_msg+0x413/0xb80 nore/rtnetlink.c: 5571 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c: 2504 netlink_unicast_kernel net/netlink/af_netlink.c: 1314 [netlin /0x7d0 net/netlink/ af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [en línea] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net /zócalo .c:2403 ___sys_sendmsg+0xf3/0x170 net/socket.c:2457 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 do_syscall_x64 arch/x86/entry/common.c:50 [en línea] arco/ x86/entrada/common.c:80

*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

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-21 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (7)

URL	Tag	Source
https://git.kernel.org/stable/c/c71c512f4a65267e6a18163f4df729c489a51035	Vuln. Introduced
https://git.kernel.org/stable/c/a969a632cbe7165d448a5528806ad120c2599397	Vuln. Introduced
https://git.kernel.org/stable/c/44d4775ca51805b376a8db5b34f650434a08e556	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/c951c08a5996365aecbc5f1a9bddec3905e1ddfc	2021-10-13
https://git.kernel.org/stable/c/3ec73ffeef54596c32aff0e73fe60971b9c8b866	2021-10-13
https://git.kernel.org/stable/c/7a1c1af341041221b3acb9d7036cc2b43e0efa75	2021-10-13
https://git.kernel.org/stable/c/a56d447f196fa9973c568f54c0d76d5391c3b0c0	2021-10-05

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"				>= 5.4.87 < 5.4.153 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4.87 < 5.4.153"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.10.5 < 5.10.73 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.10.5 < 5.10.73"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.11 < 5.14.12 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.11 < 5.14.12"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.11 < 5.15 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.11 < 5.15"		en		Affected