CVE-2021-47145

btrfs: do not BUG_ON in link_to_fixup_dir

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:

btrfs: do not BUG_ON in link_to_fixup_dir

While doing error injection testing I got the following panic

kernel BUG at fs/btrfs/tree-log.c:1862!
invalid opcode: 0000 [#1] SMP NOPTI
CPU: 1 PID: 7836 Comm: mount Not tainted 5.13.0-rc1+ #305
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
RIP: 0010:link_to_fixup_dir+0xd5/0xe0
RSP: 0018:ffffb5800180fa30 EFLAGS: 00010216
RAX: fffffffffffffffb RBX: 00000000fffffffb RCX: ffff8f595287faf0
RDX: ffffb5800180fa37 RSI: ffff8f5954978800 RDI: 0000000000000000
RBP: ffff8f5953af9450 R08: 0000000000000019 R09: 0000000000000001
R10: 000151f408682970 R11: 0000000120021001 R12: ffff8f5954978800
R13: ffff8f595287faf0 R14: ffff8f5953c77dd0 R15: 0000000000000065
FS: 00007fc5284c8c40(0000) GS:ffff8f59bbd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5287f47c0 CR3: 000000011275e002 CR4: 0000000000370ee0
Call Trace:
replay_one_buffer+0x409/0x470
? btree_read_extent_buffer_pages+0xd0/0x110
walk_up_log_tree+0x157/0x1e0
walk_log_tree+0xa6/0x1d0
btrfs_recover_log_trees+0x1da/0x360
? replay_one_extent+0x7b0/0x7b0
open_ctree+0x1486/0x1720
btrfs_mount_root.cold+0x12/0xea
? __kmalloc_track_caller+0x12f/0x240
legacy_get_tree+0x24/0x40
vfs_get_tree+0x22/0xb0
vfs_kern_mount.part.0+0x71/0xb0
btrfs_mount+0x10d/0x380
? vfs_parse_fs_string+0x4d/0x90
legacy_get_tree+0x24/0x40
vfs_get_tree+0x22/0xb0
path_mount+0x433/0xa10
__x64_sys_mount+0xe3/0x120
do_syscall_64+0x3d/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae

We can get -EIO or any number of legitimate errors from
btrfs_search_slot(), panicing here is not the appropriate response. The
error path for this code handles errors properly, simply return the
error.

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: btrfs: no haga ERROR_ON en link_to_fixup_dir Mientras realizaba pruebas de inyección de errores, obtuve el siguiente ERROR de pánico en el kernel en fs/btrfs/tree-log.c:1862. código de operación no válido: 0000 [#1] SMP NOPTI CPU: 1 PID: 7836 Comm: mount Not tainted 5.13.0-rc1+ #305 Nombre de hardware: PC estándar QEMU (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 01/04/2014 RIP: 0010:link_to_fixup_dir+0xd5/0xe0 RSP: 0018:ffffb5800180fa30 EFLAGS: 00010216 RAX: fffffffffffffffb RBX: 00000000ffffffffb RCX: ffff8f595287faf0 RDX : ffffb5800180fa37 RSI: ffff8f5954978800 RDI: 0000000000000000 RBP: ffff8f5953af9450 R08: 00000000000000019 R09: 0000000000000001 R10 : 000151f408682970 R11: 0000000120021001 R12: ffff8f5954978800 R13: ffff8f595287faf0 R14: ffff8f5953c77dd0 R15: 0000000000000065 FS: 00007 fc5284c8c40(0000) GS:ffff8f59bbd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc5287f47c0 CR3: 0 00000011275e002 CR4: 0000000000370ee0 Seguimiento de llamadas: replay_one_buffer+0x409/0x470? btree_read_extent_buffer_pages+0xd0/0x110 walk_up_log_tree+0x157/0x1e0 walk_log_tree+0xa6/0x1d0 btrfs_recover_log_trees+0x1da/0x360 ? replay_one_extent+0x7b0/0x7b0 open_ctree+0x1486/0x1720 btrfs_mount_root.cold+0x12/0xea ? __kmalloc_track_caller+0x12f/0x240 Legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 ? vfs_parse_fs_string+0x4d/0x90 Legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 path_mount+0x433/0xa10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x3d/0x80 Entry_SYSCALL_64_after_hwframe+0 x44/0xae Podemos obtener -EIO o cualquier número de errores legítimos de btrfs_search_slot() , entrar en pánico aquí no es la respuesta adecuada. La ruta de error para este código maneja los errores correctamente, simplemente devuelve el error.

*Credits: N/A

CVSS Scores

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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

2024-03-04 CVE Reserved
2024-03-25 CVE Published
2024-03-26 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (8)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/76bfd8ac20bebeae599452a03dfc5724c0475dcf	2021-06-03
https://git.kernel.org/stable/c/e934c4ee17b33bafb0444f2f9766cda7166d3c40	2021-06-03
https://git.kernel.org/stable/c/0eaf383c6a4a83c09f60fd07a1bea9f1a9181611	2021-06-03
https://git.kernel.org/stable/c/6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa	2021-06-03
https://git.kernel.org/stable/c/0ed102453aa1cd12fefde8f6b60b9519b0b1f003	2021-06-03
https://git.kernel.org/stable/c/7e13db503918820e6333811cdc6f151dcea5090a	2021-06-03
https://git.kernel.org/stable/c/b545442133580dcb2f2496133bf850824d41255c	2021-06-03
https://git.kernel.org/stable/c/91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d	2021-05-17

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"				< 4.4.271 Search vendor "Linux" for product "Linux Kernel" and version " < 4.4.271"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.9.271 Search vendor "Linux" for product "Linux Kernel" and version " < 4.9.271"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.14.235 Search vendor "Linux" for product "Linux Kernel" and version " < 4.14.235"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.19.193 Search vendor "Linux" for product "Linux Kernel" and version " < 4.19.193"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.4.124 Search vendor "Linux" for product "Linux Kernel" and version " < 5.4.124"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.10.42 Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.42"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.12.9 Search vendor "Linux" for product "Linux Kernel" and version " < 5.12.9"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.13 Search vendor "Linux" for product "Linux Kernel" and version " < 5.13"		en		Affected