CVE-2024-50121

In the Linux kernel, the following vulnerability has been resolved: nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net In the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the function `nfs4_state_destroy_net` in `nfs4_state_shutdown_net` will release all resources related to the hashed `nfs4_client`. If the `nfsd_client_shrinker` is running concurrently, the `expire_client` function will first unhash this client and then destroy it. This can lead to the following warning. Additionally, numerous use-after-free errors may occur as well. nfsd_client_shrinker echo 0 > /proc/fs/nfsd/threads expire_client nfsd_shutdown_net unhash_client ... nfs4_state_shutdown_net /* won't wait shrinker exit */ /* cancel_work(&nn->nfsd_shrinker_work) * nfsd_file for this /* won't destroy unhashed client1 */ * client1 still alive nfs4_state_destroy_net */ nfsd_file_cache_shutdown /* trigger warning */ kmem_cache_destroy(nfsd_file_slab) kmem_cache_destroy(nfsd_file_mark_slab) /* release nfsd_file and mark */ __destroy_client ==================================================================== BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on __kmem_cache_shutdown() -------------------------------------------------------------------- CPU: 4 UID: 0 PID: 764 Comm: sh Not tainted 6.12.0-rc3+ #1 dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xac/0x210 [nfsd] nfsd_destroy_serv+0x251/0x2a0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e ==================================================================== BUG nfsd_file_mark (Tainted: G B W ): Objects remaining nfsd_file_mark on __kmem_cache_shutdown() -------------------------------------------------------------------- dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xc8/0x210 [nfsd] nfsd_destroy_serv+0x251/0x2a0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e To resolve this issue, cancel `nfsd_shrinker_work` using synchronous mode in nfs4_state_shutdown_net.
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:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:*

History

08 Nov 2024, 18:05

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8
References () https://git.kernel.org/stable/c/add1df5eba163a3a6ece11cb85890e2e410baaea - () https://git.kernel.org/stable/c/add1df5eba163a3a6ece11cb85890e2e410baaea - Patch
References () https://git.kernel.org/stable/c/d5ff2fb2e7167e9483846e34148e60c0c016a1f6 - () https://git.kernel.org/stable/c/d5ff2fb2e7167e9483846e34148e60c0c016a1f6 - Patch
References () https://git.kernel.org/stable/c/f965dc0f099a54fca100acf6909abe52d0c85328 - () https://git.kernel.org/stable/c/f965dc0f099a54fca100acf6909abe52d0c85328 - Patch
CWE CWE-416
First Time Linux linux Kernel
Linux

06 Nov 2024, 18:17

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nfsd: cancelar nfsd_shrinker_work usando el modo de sincronización en nfs4_state_shutdown_net. En el caso normal, cuando ejecutamos `echo 0 > /proc/fs/nfsd/threads`, la función `nfs4_state_destroy_net` en `nfs4_state_shutdown_net` liberará todos los recursos relacionados con el `nfs4_client` con hash. Si `nfsd_client_shrinker` se está ejecutando simultáneamente, la función `expire_client` primero deshará el hash de este cliente y luego lo destruirá. Esto puede generar la siguiente advertencia. Además, también pueden ocurrir numerosos errores de use-after-free. nfsd_client_shrinker echo 0 > /proc/fs/nfsd/threads expire_client nfsd_shutdown_net unhash_client ... nfs4_state_shutdown_net /* no esperará a que el reductor salga */ /* cancel_work(&nn->nfsd_shrinker_work) * nfsd_file para esto /* no destruirá el cliente1 sin hash */ * el cliente1 sigue activo nfs4_state_destroy_net */ nfsd_file_cache_shutdown /* advertencia de activación */ kmem_cache_destroy(nfsd_file_slab) kmem_cache_destroy(nfsd_file_mark_slab) /* liberar nfsd_file y marcar */ __destroy_client ============================================================================ ERROR nfsd_file (no contaminado): objetos restantes en nfsd_file en __kmem_cache_shutdown() -------------------------------------------------------------------- CPU: 4 UID: 0 PID: 764 Comm: sh No contaminado 6.12.0-rc3+ #1 dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xac/0x210 [nfsd] nfsd_destroy_serv+0x251/0x2a0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e ========================================================================= ERROR nfsd_file_mark (Corrompido: GBW): Objetos que permanecen en nfsd_file_mark en __kmem_cache_shutdown() -------------------------------------------------------------------- dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xc8/0x210 [nfsd] Para resolver este problema, cancele `nfsd_shrinker_work` usando el modo sincrónico en nfs4_state_shutdown_net.

05 Nov 2024, 18:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-11-05 18:15

Updated : 2024-12-11 15:15


NVD link : CVE-2024-50121

Mitre link : CVE-2024-50121

CVE.ORG link : CVE-2024-50121


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

Use After Free