CVE-2024-35849

btrfs: fix information leak in btrfs_ioctl_logical_to_ino()

Severity Score

"-"

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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: fix information leak in btrfs_ioctl_logical_to_ino()

Syzbot reported the following information leak for in
btrfs_ioctl_logical_to_ino():

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
_copy_to_user+0xbc/0x110 lib/usercopy.c:40
copy_to_user include/linux/uaccess.h:191 [inline]
btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499
btrfs_ioctl+0x714/0x1260
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
__kmalloc_large_node+0x231/0x370 mm/slub.c:3921
__do_kmalloc_node mm/slub.c:3954 [inline]
__kmalloc_node+0xb07/0x1060 mm/slub.c:3973
kmalloc_node include/linux/slab.h:648 [inline]
kvmalloc_node+0xc0/0x2d0 mm/util.c:634
kvmalloc include/linux/slab.h:766 [inline]
init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779
btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480
btrfs_ioctl+0x714/0x1260
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Bytes 40-65535 of 65536 are uninitialized
Memory access of size 65536 starts at ffff888045a40000

This happens, because we're copying a 'struct btrfs_data_container' back
to user-space. This btrfs_data_container is allocated in
'init_data_container()' via kvmalloc(), which does not zero-fill the
memory.

Fix this by using kvzalloc() which zeroes out the memory on allocation.

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: btrfs: corrige la fuga de información en btrfs_ioctl_logic_to_ino() Syzbot informó la siguiente fuga de información en btrfs_ioctl_logic_to_ino(): ERROR: KMSAN: kernel-infoleak en instrument_copy_to_user include/linux/instrumented.h: 114 [en línea] ERROR: KMSAN: kernel-infoleak en _copy_to_user+0xbc/0x110 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [en línea] _copy_to_user+0xbc/0x110 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [en línea] btrfs_ioctl_logic_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499 btrfs_ioctl+0x714/0x1260 vfs_ioctl fs/ioctl.c:51 [en línea] __do_sys_ioctl fs/ioctl.c :904 [en línea] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h: 17 do_syscall_x64 arco/ x86/entry/common.c:52 [en línea] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit se creó en: __kmalloc_large_node+0x231/0x370 mm/slub.c:3921 __do_kmalloc_node mm/slub.c:3954 [en línea] __kmalloc_node+0xb07/0x1060 mm/slub.c:3973 kmalloc_node include/linux/slab.h:648 [en línea] kvmalloc_node+0xc0/0x2d0 mm/util.c:634 kvmalloc incluye /linux/slab.h:766 [en línea] init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779 btrfs_ioctl_logic_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480 btrfs_ioctl+0x714/0x1260 ctl fs/ioctl.c :51 [en línea] __do_sys_ioctl fs/ioctl.c:904 [en línea] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x Arco 3b50/x86/incluye /generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [en línea] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f Bytes 40-65535 de 65536 no están inicializados El acceso a la memoria de tamaño 65536 comienza en ffff888045a40000. Esto sucede porque estamos copiando una 'estructura btrfs_data_container' nuevamente al espacio de usuario. Este btrfs_data_container se asigna en 'init_data_container()' a través de kvmalloc(), que no llena la memoria con ceros. Solucione este problema usando kvzalloc() que pone a cero la memoria al asignarla.

*Credits: N/A

CVSS Scores

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Scope

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Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-17 CVE Reserved
2024-05-17 CVE Published
2024-05-18 EPSS Updated
2024-08-02 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (10)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/689efe22e9b5b7d9d523119a9a5c3c17107a0772	2024-05-02
https://git.kernel.org/stable/c/73db209dcd4ae026021234d40cfcb2fb5b564b86	2024-05-02
https://git.kernel.org/stable/c/30189e54ba80e3209d34cfeea87b848f6ae025e6	2024-05-02
https://git.kernel.org/stable/c/e58047553a4e859dafc8d1d901e1de77c9dd922d	2024-05-02
https://git.kernel.org/stable/c/8bdbcfaf3eac42f98e5486b3d7e130fa287811f6	2024-05-02
https://git.kernel.org/stable/c/3a63cee1a5e14a3e52c19142c61dd5fcb524f6dc	2024-05-02
https://git.kernel.org/stable/c/fddc19631c51d9c17d43e9f822a7bc403af88d54	2024-05-02
https://git.kernel.org/stable/c/2f7ef5bb4a2f3e481ef05fab946edb97c84f67cf	2024-04-18

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"				< 4.19.313 Search vendor "Linux" for product "Linux Kernel" and version " < 4.19.313"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.4.275 Search vendor "Linux" for product "Linux Kernel" and version " < 5.4.275"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.10.216 Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.216"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.15.158 Search vendor "Linux" for product "Linux Kernel" and version " < 5.15.158"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.1.90 Search vendor "Linux" for product "Linux Kernel" and version " < 6.1.90"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.6.30 Search vendor "Linux" for product "Linux Kernel" and version " < 6.6.30"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.8.9 Search vendor "Linux" for product "Linux Kernel" and version " < 6.8.9"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.9 Search vendor "Linux" for product "Linux Kernel" and version " < 6.9"		en		Affected