CVE-2021-46956

virtiofs: fix memory leak in virtio_fs_probe()

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:

virtiofs: fix memory leak in virtio_fs_probe()

When accidentally passing twice the same tag to qemu, kmemleak ended up
reporting a memory leak in virtiofs. Also, looking at the log I saw the
following error (that's when I realised the duplicated tag):

virtiofs: probe of virtio5 failed with error -17

Here's the kmemleak log for reference:

unreferenced object 0xffff888103d47800 (size 1024):
comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
backtrace:
[<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
[<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
[<000000004d6baf3c>] really_probe+0xea/0x430
[<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
[<00000000196f47a7>] __driver_attach+0x98/0x140
[<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
[<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
[<0000000032b09ba7>] driver_register+0x8f/0xe0
[<00000000cdd55998>] 0xffffffffa002c013
[<000000000ea196a2>] do_one_initcall+0x64/0x2e0
[<0000000008f727ce>] do_init_module+0x5c/0x260
[<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
[<00000000ad2f48c6>] do_syscall_64+0x33/0x40
[<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: virtiofs: corrige pérdida de memoria en virtio_fs_probe() Al pasar accidentalmente dos veces la misma etiqueta a qemu, kmemleak terminó reportando una pérdida de memoria en virtiofs. Además, mirando el registro vi el siguiente error (fue entonces cuando me di cuenta de la etiqueta duplicada): virtiofs: la sonda de virtio5 falló con el error -17 Aquí está el registro kmemleak como referencia: objeto sin referencia 0xffff888103d47800 (tamaño 1024): comm "systemd- udevd", pid 118, jiffies 4294893780 (edad 18.340 s) volcado hexadecimal (primeros 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 ......N....... ... ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................ rastreo: [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs] [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210 [<000000004d6baf3c>] very_probe+0xea/0x430 [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0 [<00000000196f47a7 >] __driver_attach+0x98/0x140 [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0 [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0 [<0000000032b09ba7>] driver_register+0x8f/0xe0 [<00000000cdd55998>] 0xffffffffa002c013 [<000000000ea196a2> ] do_one_initcall+0x64/0x2e0 [<0000000008f727ce>] do_init_module+0x5c/0x260 [<000000003cdedab6> ] __do_sys_finit_module+0xb5/0x120 [<00000000ad2f48c6>] do_syscall_64+0x33/0x40 [<00000000809526b5>] Entry_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

2024-02-27 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 (6)

URL	Tag	Source
https://git.kernel.org/stable/c/a62a8ef9d97da23762a588592c8b8eb50a8deb6a	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/310efc95c72c13faf855c692d19cd4d054d827c8	2021-05-11
https://git.kernel.org/stable/c/d19555ff225d0896a33246a49279e6d578095f15	2021-05-11
https://git.kernel.org/stable/c/9b9d60c0eb8ada99cce2a9ab5c15dffc523b01ae	2021-05-12
https://git.kernel.org/stable/c/5116e79fc6e6725b8acdad8b7e928a83ab7b47e6	2021-05-12
https://git.kernel.org/stable/c/c79c5e0178922a9e092ec8fed026750f39dcaef4	2021-04-14

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 < 5.4.118 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.4.118"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 5.10.36 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.10.36"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 5.11.20 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.11.20"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 5.12.3 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.12.3"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 5.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.13"		en		Affected