CVE-2021-47237

net: hamradio: fix memory leak in mkiss_close

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: hamradio: fix memory leak in mkiss_close

My local syzbot instance hit memory leak in
mkiss_open()[1]. The problem was in missing
free_netdev() in mkiss_close().

In mkiss_open() netdevice is allocated and then
registered, but in mkiss_close() netdevice was
only unregistered, but not freed.

Fail log:

BUG: memory leak
unreferenced object 0xffff8880281ba000 (size 4096):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
61 78 30 00 00 00 00 00 00 00 00 00 00 00 00 00 ax0.............
00 27 fa 2a 80 88 ff ff 00 00 00 00 00 00 00 00 .'.*............
backtrace:
[<ffffffff81a27201>] kvmalloc_node+0x61/0xf0
[<ffffffff8706e7e8>] alloc_netdev_mqs+0x98/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff8880141a9a00 (size 96):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
e8 a2 1b 28 80 88 ff ff e8 a2 1b 28 80 88 ff ff ...(.......(....
98 92 9c aa b0 40 02 00 00 00 00 00 00 00 00 00 .....@..........
backtrace:
[<ffffffff8709f68b>] __hw_addr_create_ex+0x5b/0x310
[<ffffffff8709fb38>] __hw_addr_add_ex+0x1f8/0x2b0
[<ffffffff870a0c7b>] dev_addr_init+0x10b/0x1f0
[<ffffffff8706e88b>] alloc_netdev_mqs+0x13b/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff8880219bfc00 (size 512):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
00 a0 1b 28 80 88 ff ff 80 8f b1 8d ff ff ff ff ...(............
80 8f b1 8d ff ff ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81a27201>] kvmalloc_node+0x61/0xf0
[<ffffffff8706eec7>] alloc_netdev_mqs+0x777/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888029b2b200 (size 256):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81a27201>] kvmalloc_node+0x61/0xf0
[<ffffffff8706f062>] alloc_netdev_mqs+0x912/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net: hamradio: corrige la pérdida de memoria en mkiss_close. Mi instancia local de syzbot tuvo una pérdida de memoria en mkiss_open()[1]. El problema estaba en que faltaba free_netdev() en mkiss_close(). En mkiss_open() el dispositivo de red se asigna y luego se registra, pero en mkiss_close() el dispositivo de red solo se anula del registro, pero no se libera. Registro de errores: ERROR: pérdida de memoria, objeto sin referencia 0xffff8880281ba000 (tamaño 4096): comunicación "syz-executor.1", pid 11443, santiamén 4295046091 (edad 17,660 s) volcado hexadecimal (primeros 32 bytes): 61 78 30 00 00 00 00 00 00 00 00 00 00 00 00 00 ax0............. 00 27 fa 2a 80 88 ff ff 00 00 00 00 00 00 00 00 .'.*....... .... seguimiento: [] kvmalloc_node+0x61/0xf0 [] alloc_netdev_mqs+0x98/0xe80 [] mkiss_open+0xb2/0x6f0 [] tty_ldisc_open+0x9b/0x110 [ ] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] Entry_SYSCALL_64_after_hwframe+0x44/0xae ERROR : pérdida de memoria objeto sin referencia 0xffff8880141a9a00 (tamaño 96): comm "syz-executor.1", pid 11443, jiffies 4295046091 (edad 17.660s) volcado hexadecimal (primeros 32 bytes): e8 a2 1b 28 80 88 ff ff e8 a2 1b 28 80 88 ff ff ...(.......(.... 98 92 9c aa b0 40 02 00 00 00 00 00 00 00 00 00 .....@....... .. seguimiento: [] __hw_addr_create_ex+0x5b/0x310 [] __hw_addr_add_ex+0x1f8/0x2b0 [] f0 [] alloc_netdev_mqs+0x13b/0xe80 [] mkiss_open +0xb2/0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] Entry_SYSCALL_64_after_hwframe+0x44/0xae ERROR: pérdida de memoria objeto sin referencia 0xffff8880219bfc00 (tamaño 512): comm "syz-executor.1", pid 11443, jiffies 95046091 (edad 17.660 años) volcado hexadecimal (primeros 32 bytes): 00 a0 1b 28 80 88 ff ff 80 8f b1 8d ff ff ff ...(............ 80 8f b1 8d ff ff ff ff 00 00 00 00 00 00 00 00 ................ rastreo inverso: [] kvmalloc_node+0x61/0xf0 [] alloc_netdev_mqs+0x777/0xe80 [] mkiss_open+0xb2 /0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] Entry_SYSCALL_64_after_hwframe+0x44/0xae ERROR: pérdida de memoria objeto sin referencia 0xffff888029b2b200 (tamaño 256): comm "syz-executor.1", pid 11443, jiffies 046091 (edad 17.660 años) volcado hexadecimal (primero 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ rastreo inverso: [] kvmalloc_node+0x61/0xf0 [] alloc_netdev_mqs+0x912/0xe80 [] mkiss_open+0xb2/0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+ 0x3a/0xb0 [] entrada_SYSCALL_64_after_hwframe+0x44/0xae

*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

2024-04-10 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-11-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (9)

URL	Tag	Source
https://git.kernel.org/stable/c/815f62bf742718458ba822a7e1f51f285eb997f2	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/c634ba0b4159838ff45a60d3a0ace3b4118077a5	2021-06-30
https://git.kernel.org/stable/c/3942d0f9ace1a95a74930b5b4fc0e5005c62b37b	2021-06-30
https://git.kernel.org/stable/c/765a8a04f828db7222b36a42b1031f576bfe95c3	2021-06-30
https://git.kernel.org/stable/c/c16c4716a1b5ba4f83c7e00da457cba06761f119	2021-06-30
https://git.kernel.org/stable/c/a49cbb762ef20655f5c91abdc13658b0af5e159d	2021-06-23
https://git.kernel.org/stable/c/290b0b6432e2599021db0b8d6046f756d931c29f	2021-06-23
https://git.kernel.org/stable/c/f4de2b43d13b7cf3ced9310e371b90c836dbd7cd	2021-06-23
https://git.kernel.org/stable/c/7edcc682301492380fbdd604b4516af5ae667a13	2021-06-17

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"				>= 2.6.14 < 4.4.274 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 4.4.274"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 4.9.274 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 4.9.274"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 4.14.238 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 4.14.238"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 4.19.196 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 4.19.196"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 5.4.128 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 5.4.128"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 5.10.46 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 5.10.46"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 5.12.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 5.12.13"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.14 < 5.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.14 < 5.13"		en		Affected