CVE-2024-49870

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  2. Vulnerabilities (CVE)
  3. CVE-2024-49870

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

I

n the Linux kernel, the following vulnerability has been resolved: cachefiles: fix dentry leak in cachefiles_open_file() A dentry leak may be caused when a lookup cookie and a cull are concurrent: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // get dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Returns an error but doesn't put dentry After that the following WARNING will be triggered when the backend folder is umounted: ================================================================== BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda] WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Call Trace: <TASK> d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ================================================================== Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released. Therefore release that reference count in cachefiles_look_up_object() to fix the above issue and simplify the code.

References
Link Resource
https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b Patch
https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151 Patch
https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410 Patch
https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c Patch
https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1 Patch
https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*
History

03 Nov 2025, 23:16

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html -

25 Oct 2024, 12:55

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
First Time Linux
Linux linux Kernel
CWE CWE-401
CPE cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b - () https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b - Patch
References () https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151 - () https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151 - Patch
References () https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410 - () https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410 - Patch
References () https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c - () https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c - Patch
References () https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1 - () https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1 - Patch

23 Oct 2024, 15:13

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: cachefiles: se corrige la pérdida de dentry en cachefiles_open_file(). Una pérdida de dentry puede producirse cuando una cookie de búsqueda y un cull son concurrentes: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // obtener dentry cachefiles_cull inode-&gt;i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode-&gt;i_flags &amp; S_KERNEL_FILE)) can_use = true return false return false // Devuelve un error pero no coloca dentry Después de eso, se activará la siguiente ADVERTENCIA cuando se desmonte la carpeta del backend: ===================================================================== ERROR: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} todavía en uso (1) [desmontaje de ext4 sda] ADVERTENCIA: CPU: 4 PID: 359261 en fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount No contaminado 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Rastreo de llamadas: d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ==================================================================== Independientemente de si cachefiles_open_file() devuelve verdadero o falso, el recuento de referencias obtenido por lookup_positive_unlocked() en cachefiles_look_up_object() debe liberarse. Por lo tanto, libere ese recuento de referencias en cachefiles_look_up_object() para solucionar el problema anterior y simplificar el código.

21 Oct 2024, 18:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-10-21 18:15

Updated : 2025-11-03 23:16

NVD link : CVE-2024-49870

Mitre link : CVE-2024-49870

CVE.ORG link : CVE-2024-49870

JSON object : View

Products Affected

linux

CWE
CWE-401

Missing Release of Memory after Effective Lifetime