CVE-2021-47237

net: hamradio: fix memory leak in mkiss_close

Severity Score

5.5

*CVSS v3

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

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

*Credits: N/A

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

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-04-10 CVE Reserved
2024-05-21 CVE Published
2024-12-19 CVE Updated
2025-03-30 EPSS 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