CVE-2025-21999

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-21999
In the Linux kernel, the following vulnerability has been resolved: proc: fix UAF in proc_get_inode() Fix race between rmmod and /proc/XXX's inode instantiation. The bug is that pde->proc_ops don't belong to /proc, it belongs to a module, therefore dereferencing it after /proc entry has been registered is a bug unless use_pde/unuse_pde() pair has been used. use_pde/unuse_pde can be avoided (2 atomic ops!) because pde->proc_ops never changes so information necessary for inode instantiation can be saved _before_ proc_register() in PDE itself and used later, avoiding pde->proc_ops->... dereference. rmmod lookup sys_delete_module proc_lookup_de pde_get(de); proc_get_inode(dir->i_sb, de); mod->exit() proc_remove remove_proc_subtree proc_entry_rundown(de); free_module(mod); if (S_ISREG(inode->i_mode)) if (de->proc_ops->proc_read_iter) --> As module is already freed, will trigger UAF BUG: unable to handle page fault for address: fffffbfff80a702b PGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:proc_get_inode+0x302/0x6e0 RSP: 0018:ffff88811c837998 EFLAGS: 00010a06 RAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007 RDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158 RBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20 R10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0 R13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001 FS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> proc_lookup_de+0x11f/0x2e0 __lookup_slow+0x188/0x350 walk_component+0x2ab/0x4f0 path_lookupat+0x120/0x660 filename_lookup+0x1ce/0x560 vfs_statx+0xac/0x150 __do_sys_newstat+0x96/0x110 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e [adobriyan@gmail.com: don't do 2 atomic ops on the common path]

7.8 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa
https://git.kernel.org/stable/c/63b53198aff2e4e6c5866a4ff73c7891f958ffa4 Patch
https://git.kernel.org/stable/c/64dc7c68e040251d9ec6e989acb69f8f6ae4a10b Patch
https://git.kernel.org/stable/c/654b33ada4ab5e926cd9c570196fefa7bec7c1df Patch
https://git.kernel.org/stable/c/966f331403dc3ed04ff64eaf3930cf1267965e53 Patch
https://git.kernel.org/stable/c/eda279586e571b05dff44d48e05f8977ad05855d
https://git.kernel.org/stable/c/ede3e8ac90ae106f0b29cd759aadebc1568f1308 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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
History

10 Apr 2025, 13:15

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa -
  • () https://git.kernel.org/stable/c/eda279586e571b05dff44d48e05f8977ad05855d -

08 Apr 2025, 15:49

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
References () https://git.kernel.org/stable/c/63b53198aff2e4e6c5866a4ff73c7891f958ffa4 - () https://git.kernel.org/stable/c/63b53198aff2e4e6c5866a4ff73c7891f958ffa4 - Patch
References () https://git.kernel.org/stable/c/64dc7c68e040251d9ec6e989acb69f8f6ae4a10b - () https://git.kernel.org/stable/c/64dc7c68e040251d9ec6e989acb69f8f6ae4a10b - Patch
References () https://git.kernel.org/stable/c/654b33ada4ab5e926cd9c570196fefa7bec7c1df - () https://git.kernel.org/stable/c/654b33ada4ab5e926cd9c570196fefa7bec7c1df - Patch
References () https://git.kernel.org/stable/c/966f331403dc3ed04ff64eaf3930cf1267965e53 - () https://git.kernel.org/stable/c/966f331403dc3ed04ff64eaf3930cf1267965e53 - Patch
References () https://git.kernel.org/stable/c/ede3e8ac90ae106f0b29cd759aadebc1568f1308 - () https://git.kernel.org/stable/c/ede3e8ac90ae106f0b29cd759aadebc1568f1308 - Patch

03 Apr 2025, 16:15

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.8
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: proc: corrección de UAF en proc_get_inode(). Corrección de la competencia entre rmmod y la instanciación de inodo de /proc/XXX. El error es que pde-&gt;proc_ops no pertenece a /proc, sino a un módulo; por lo tanto, desreferenciarlo después de registrar la entrada /proc es un error, a menos que se haya usado el par use_pde/unuse_pde(). Se puede evitar usar_pde/unuse_pde (¡2 operaciones atómicas!) porque pde-&gt;proc_ops nunca cambia, de modo que la información necesaria para la instanciación de inodo se puede guardar _antes_ de proc_register() en el propio PDE y usarse más tarde, evitando la desreferencia de pde-&gt;proc_ops-&gt;... . rmmod lookup sys_delete_module proc_lookup_de pde_get(de); proc_get_inode(dir-&gt;i_sb, de); mod-&gt;exit() proc_remove eliminar_subárbol_proc proc_entry_rundown(de); liberar_módulo(mod); if (S_ISREG(inode-&gt;i_mode)) if (de-&gt;proc_ops-&gt;proc_read_iter) --&gt; Como el módulo ya está liberado, se activará UAF ERROR: no se puede manejar el error de página para la dirección: fffffbfff80a702b PGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:proc_get_inode+0x302/0x6e0 RSP: 0018:ffff88811c837998 EFLAGS: 00010a06 RAX: dffffc0000000000 RBX: fffffffc0538140 RCX: 0000000000000007 RDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158 RBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20 R10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0 R13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001 FS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0 DR0: 00000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Rastreo de llamadas: proc_lookup_de+0x11f/0x2e0 __lookup_slow+0x188/0x350 walk_component+0x2ab/0x4f0 path_lookupat+0x120/0x660 filename_lookup+0x1ce/0x560 vfs_statx+0xac/0x150 __do_sys_newstat+0x96/0x110 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e [adobriyan@gmail.com: no realice 2 operaciones atómicas en la ruta común]
CWE CWE-416

03 Apr 2025, 08:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-04-03 08:15

Updated : 2025-04-10 13:15

NVD link : CVE-2025-21999

Mitre link : CVE-2025-21999

CVE.ORG link : CVE-2025-21999

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

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