CVE-2021-46982

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-46982
In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix race condition of overwrite vs truncate pos_fsstress testcase complains a panic as belew: ------------[ cut here ]------------ kernel BUG at fs/f2fs/compress.c:1082! invalid opcode: 0000 [#1] SMP PTI CPU: 4 PID: 2753477 Comm: kworker/u16:2 Tainted: G OE 5.12.0-rc1-custom #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: writeback wb_workfn (flush-252:16) RIP: 0010:prepare_compress_overwrite+0x4c0/0x760 [f2fs] Call Trace: f2fs_prepare_compress_overwrite+0x5f/0x80 [f2fs] f2fs_write_cache_pages+0x468/0x8a0 [f2fs] f2fs_write_data_pages+0x2a4/0x2f0 [f2fs] do_writepages+0x38/0xc0 __writeback_single_inode+0x44/0x2a0 writeback_sb_inodes+0x223/0x4d0 __writeback_inodes_wb+0x56/0xf0 wb_writeback+0x1dd/0x290 wb_workfn+0x309/0x500 process_one_work+0x220/0x3c0 worker_thread+0x53/0x420 kthread+0x12f/0x150 ret_from_fork+0x22/0x30 The root cause is truncate() may race with overwrite as below, so that one reference count left in page can not guarantee the page attaching in mapping tree all the time, after truncation, later find_lock_page() may return NULL pointer. - prepare_compress_overwrite - f2fs_pagecache_get_page - unlock_page - f2fs_setattr - truncate_setsize - truncate_inode_page - delete_from_page_cache - find_lock_page Fix this by avoiding referencing updated page.

4.7 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.0 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff Patch
https://git.kernel.org/stable/c/64acb100fe3beb5d20184d0ae3307235bd3555c4 Patch
https://git.kernel.org/stable/c/936158b15e2648253afb824d252c910c496d34b5 Patch
https://git.kernel.org/stable/c/a949dc5f2c5cfe0c910b664650f45371254c0744 Patch
https://git.kernel.org/stable/c/5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff Patch
https://git.kernel.org/stable/c/64acb100fe3beb5d20184d0ae3307235bd3555c4 Patch
https://git.kernel.org/stable/c/936158b15e2648253afb824d252c910c496d34b5 Patch
https://git.kernel.org/stable/c/a949dc5f2c5cfe0c910b664650f45371254c0744 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
History

31 Dec 2024, 16:08

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 4.7
References () https://git.kernel.org/stable/c/5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff - () https://git.kernel.org/stable/c/5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff - Patch
References () https://git.kernel.org/stable/c/64acb100fe3beb5d20184d0ae3307235bd3555c4 - () https://git.kernel.org/stable/c/64acb100fe3beb5d20184d0ae3307235bd3555c4 - Patch
References () https://git.kernel.org/stable/c/936158b15e2648253afb824d252c910c496d34b5 - () https://git.kernel.org/stable/c/936158b15e2648253afb824d252c910c496d34b5 - Patch
References () https://git.kernel.org/stable/c/a949dc5f2c5cfe0c910b664650f45371254c0744 - () https://git.kernel.org/stable/c/a949dc5f2c5cfe0c910b664650f45371254c0744 - Patch
CPE cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CWE CWE-362
First Time Linux
Linux linux Kernel

21 Nov 2024, 06:35

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff - () https://git.kernel.org/stable/c/5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff -
References () https://git.kernel.org/stable/c/64acb100fe3beb5d20184d0ae3307235bd3555c4 - () https://git.kernel.org/stable/c/64acb100fe3beb5d20184d0ae3307235bd3555c4 -
References () https://git.kernel.org/stable/c/936158b15e2648253afb824d252c910c496d34b5 - () https://git.kernel.org/stable/c/936158b15e2648253afb824d252c910c496d34b5 -
References () https://git.kernel.org/stable/c/a949dc5f2c5cfe0c910b664650f45371254c0744 - () https://git.kernel.org/stable/c/a949dc5f2c5cfe0c910b664650f45371254c0744 -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: f2fs: comprimir: corregir la condición de ejecución de sobrescritura frente a truncar pos_fsstress testcase presenta un pánico como se muestra a continuación: ------------[ cortar aquí ]--- --------- ¡ERROR del kernel en fs/f2fs/compress.c:1082! código de operación no válido: 0000 [#1] SMP PTI CPU: 4 PID: 2753477 Comm: kworker/u16:2 Contaminado: G OE 5.12.0-rc1-custom #1 Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.14.0-2 01/04/2014 Cola de trabajo: reescritura wb_workfn (flush-252:16) RIP: 0010:prepare_compress_overwrite+0x4c0/0x760 [f2fs] Seguimiento de llamadas: f2fs_prepare_compress_overwrite+0x5f/0x80 [f2fs] f2fs_write_cache_pages+ 0x468/0x8a0 [f2fs] f2fs_write_data_pages+0x2a4/0x2f0 [f2fs] do_writepages+0x38/0xc0 __writeback_single_inode+0x44/0x2a0 writeback_sb_inodes+0x223/0x4d0 __writeback_inodes_wb+0x56/0xf0 wb_writeback+0x1dd/0 x290 wb_workfn+0x309/0x500 proceso_one_work+0x220/0x3c0 trabajador_thread+0x53/ 0x420 kthread+0x12f/0x150 ret_from_fork+0x22/0x30 La causa principal es que truncate() puede correr con sobrescritura como se muestra a continuación, por lo que un recuento de referencias restante en la página no puede garantizar que la página se adjunte en el árbol de mapeo todo el tiempo, después del truncamiento, más adelante find_lock_page() puede devolver un puntero NULL. - prepare_compress_overwrite - f2fs_pagecache_get_page - unlock_page - f2fs_setattr - truncate_setsize - truncate_inode_page - delete_from_page_cache - find_lock_page Solucione este problema evitando hacer referencia a la página actualizada.

28 Feb 2024, 09:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-02-28 09:15

Updated : 2024-12-31 16:08

NVD link : CVE-2021-46982

Mitre link : CVE-2021-46982

CVE.ORG link : CVE-2021-46982

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')