CVE-2024-50047
Estado: ModificadaAlta (7.8)—
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix UAF in async decryption
Doing an async decryption (large read) crashes with a slab-use-after-free way down in the crypto API.
This is because TFM is being used in parallel.
Fix this by allocating a new AEAD TFM for async decryption, but keep the existing one for synchronous READ cases (similar to what is done in smb3_calc_signature()).
Also remove the calls to aead_request_set_callback() and crypto_wait_req() since it's always going to be a synchronous operation.
Detalles técnicos trazas, registros y código del informe original
Reproducer:
# mount.cifs -o ...,seal,esize=1 //srv/share /mnt
# dd if=/mnt/largefile of=/dev/null
...
[ 194.196391] ==================================================================
[ 194.196844] BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xc1/0x110
[ 194.197269] Read of size 8 at addr ffff888112bd0448 by task kworker/u77:2/899
[ 194.197707]
[ 194.197818] CPU: 12 UID: 0 PID: 899 Comm: kworker/u77:2 Not tainted 6.11.0-lku-00028-gfca3ca14a17a-dirty #43
[ 194.198400] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014
[ 194.199046] Workqueue: smb3decryptd smb2_decrypt_offload [cifs]
[ 194.200032] Call Trace:
[ 194.200191] <TASK>
[ 194.200327] dump_stack_lvl+0x4e/0x70
[ 194.200558] ? gf128mul_4k_lle+0xc1/0x110
[ 194.200809] print_report+0x174/0x505
[ 194.201040] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 194.201352] ? srso_return_thunk+0x5/0x5f
[ 194.201604] ? __virt_addr_valid+0xdf/0x1c0
[ 194.201868] ? gf128mul_4k_lle+0xc1/0x110
[ 194.202128] kasan_report+0xc8/0x150
[ 194.202361] ? gf128mul_4k_lle+0xc1/0x110
[ 194.202616] gf128mul_4k_lle+0xc1/0x110
[ 194.202863] ghash_update+0x184/0x210
[ 194.203103] shash_ahash_update+0x184/0x2a0
[ 194.203377] ? __pfx_shash_ahash_update+0x10/0x10
[ 194.203651] ? srso_return_thunk+0x5/0x5f
[ 194.203877] ? crypto_gcm_init_common+0x1ba/0x340
[ 194.204142] gcm_hash_assoc_remain_continue+0x10a/0x140
[ 194.204434] crypt_message+0xec1/0x10a0 [cifs]
[ 194.206489] ? __pfx_crypt_message+0x10/0x10 [cifs]
[ 194.208507] ? srso_return_thunk+0x5/0x5f
[ 194.209205] ? srso_return_thunk+0x5/0x5f
[ 194.209925] ? srso_return_thunk+0x5/0x5f
[ 194.210443] ? srso_return_thunk+0x5/0x5f
[ 194.211037] decrypt_raw_data+0x15f/0x250 [cifs]
[ 194.212906] ? __pfx_decrypt_raw_data+0x10/0x10 [cifs]
[ 194.214670] ? srso_return_thunk+0x5/0x5f
[ 194.215193] smb2_decrypt_offload+0x12a/0x6c0 [cifs]CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.52%
- Percentil entre todas las CVEs puntuadas: 42
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1499.004Application or System Exploitationimpact75 %
Vulnerabilidad local (AV:L/PR:L) de uso después de liberación (UAF) en descifrado asincrónico SMB3 que causa crash de kernel, resultando en DoS de aplicación sin privilegios de root.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-416
Referencias
- https://git.kernel.org/stable/c/0809fb86ad13b29e1d6d491364fc7ea4fb545995
- https://git.kernel.org/stable/c/538c26d9bf70c90edc460d18c81008a4e555925a
- https://git.kernel.org/stable/c/8f14a476abba13144df5434871a7225fd29af633
- https://git.kernel.org/stable/c/b0abcd65ec545701b8793e12bc27dc98042b151a
- https://git.kernel.org/stable/c/bce966530fd5542bbb422cb45ecb775f7a1a6bc3
- https://git.kernel.org/stable/c/ef51c0d544b1518b35364480317ab6d3468f205d
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
JSON original (NVD)
Mostrar
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"published": "2024-10-21T20:15:17.507",
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"source": "nvd@nist.gov",
"description": [
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"value": "CWE-416"
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF in async decryption\n\nDoing an async decryption (large read) crashes with a\nslab-use-after-free way down in the crypto API.\n\nReproducer:\n # mount.cifs -o ...,seal,esize=1 //srv/share /mnt\n # dd if=/mnt/largefile of=/dev/null\n ...\n [ 194.196391] ==================================================================\n [ 194.196844] BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xc1/0x110\n [ 194.197269] Read of size 8 at addr ffff888112bd0448 by task kworker/u77:2/899\n [ 194.197707]\n [ 194.197818] CPU: 12 UID: 0 PID: 899 Comm: kworker/u77:2 Not tainted 6.11.0-lku-00028-gfca3ca14a17a-dirty #43\n [ 194.198400] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014\n [ 194.199046] Workqueue: smb3decryptd smb2_decrypt_offload [cifs]\n [ 194.200032] Call Trace:\n [ 194.200191] <TASK>\n [ 194.200327] dump_stack_lvl+0x4e/0x70\n [ 194.200558] ? gf128mul_4k_lle+0xc1/0x110\n [ 194.200809] print_report+0x174/0x505\n [ 194.201040] ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n [ 194.201352] ? srso_return_thunk+0x5/0x5f\n [ 194.201604] ? __virt_addr_valid+0xdf/0x1c0\n [ 194.201868] ? gf128mul_4k_lle+0xc1/0x110\n [ 194.202128] kasan_report+0xc8/0x150\n [ 194.202361] ? gf128mul_4k_lle+0xc1/0x110\n [ 194.202616] gf128mul_4k_lle+0xc1/0x110\n [ 194.202863] ghash_update+0x184/0x210\n [ 194.203103] shash_ahash_update+0x184/0x2a0\n [ 194.203377] ? __pfx_shash_ahash_update+0x10/0x10\n [ 194.203651] ? srso_return_thunk+0x5/0x5f\n [ 194.203877] ? crypto_gcm_init_common+0x1ba/0x340\n [ 194.204142] gcm_hash_assoc_remain_continue+0x10a/0x140\n [ 194.204434] crypt_message+0xec1/0x10a0 [cifs]\n [ 194.206489] ? __pfx_crypt_message+0x10/0x10 [cifs]\n [ 194.208507] ? srso_return_thunk+0x5/0x5f\n [ 194.209205] ? srso_return_thunk+0x5/0x5f\n [ 194.209925] ? srso_return_thunk+0x5/0x5f\n [ 194.210443] ? srso_return_thunk+0x5/0x5f\n [ 194.211037] decrypt_raw_data+0x15f/0x250 [cifs]\n [ 194.212906] ? __pfx_decrypt_raw_data+0x10/0x10 [cifs]\n [ 194.214670] ? srso_return_thunk+0x5/0x5f\n [ 194.215193] smb2_decrypt_offload+0x12a/0x6c0 [cifs]\n\nThis is because TFM is being used in parallel.\n\nFix this by allocating a new AEAD TFM for async decryption, but keep\nthe existing one for synchronous READ cases (similar to what is done\nin smb3_calc_signature()).\n\nAlso remove the calls to aead_request_set_callback() and\ncrypto_wait_req() since it's always going to be a synchronous operation."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: smb: cliente: corregir UAF en descifrado asincrónico Al realizar un descifrado asincrónico (lectura grande), se produce un bloqueo con un método slab-use-after-free en la API de cifrado. Reproductor: # mount.cifs -o ...,seal,esize=1 //srv/share /mnt # dd if=/mnt/largefile of=/dev/null ... [ 194.196391] ===================================================================== [ 194.196844] ERROR: KASAN: slab-use-after-free en gf128mul_4k_lle+0xc1/0x110 [ 194.197269] Lectura de tamaño 8 en la dirección ffff888112bd0448 por la tarea kworker/u77:2/899 [ 194.197707] [ 194.197818] CPU: 12 UID: 0 PID: 899 Comm: kworker/u77:2 No contaminado 6.11.0-lku-00028-gfca3ca14a17a-dirty #43 [ 194.198400] Nombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014 [ 194.199046] Cola de trabajo: smb3decryptd smb2_decrypt_offload [cifs] [ 194.200032] Seguimiento de llamadas: [ 194.200191] [ [194.200327] dump_stack_lvl+0x4e/0x70 [194.200558] ? gf128mul_4k_lle+0xc1/0x110 [194.200809] print_report+0x174/0x505 [194.201040] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [194.201352] ? srso_return_thunk+0x5/0x5f [194.201604] ? __virt_addr_valid+0xdf/0x1c0 [194.201868] ? gf128mul_4k_lle+0xc1/0x110 [ 194.202128] kasan_report+0xc8/0x150 [ 194.202361] ? gf128mul_4k_lle+0xc1/0x110 [ 194.202616] gf128mul_4k_lle+0xc1/0x110 [ 194.202863] ghash_update+0x184/0x210 [ 194.203103] shash_ahash_update+0x184/0x2a0 [ 194.203377] ? __pfx_shash_ahash_update+0x10/0x10 [ 194.203651] ? srso_return_thunk+0x5/0x5f [ 194.203877] ? crypto_gcm_init_common+0x1ba/0x340 [ 194.204142] gcm_hash_assoc_remain_continue+0x10a/0x140 [ 194.204434] crypt_message+0xec1/0x10a0 [cifs] [ 194.206489] ? __pfx_crypt_message+0x10/0x10 [cifs] [ 194.208507] ? srso_return_thunk+0x5/0x5f [ 194.209205] ? srso_return_thunk+0x5/0x5f [ 194.209925] ? srso_return_thunk+0x5/0x5f [ 194.210443] ? srso_return_thunk+0x5/0x5f [ 194.211037] decrypt_raw_data+0x15f/0x250 [cifs] [ 194.212906] ? __pfx_decrypt_raw_data+0x10/0x10 [cifs] [ 194.214670] ? srso_return_thunk+0x5/0x5f [ 194.215193] smb2_decrypt_offload+0x12a/0x6c0 [cifs] Esto se debe a que TFM se está utilizando en paralelo. Solucione esto asignando un nuevo TFM AEAD para el descifrado asincrónico, pero conserve el existente para los casos de LECTURA sincrónica (similar a lo que se hace en smb3_calc_signature()). También elimine las llamadas a aead_request_set_callback() y crypto_wait_req() ya que siempre será una operación sincrónica."
}
],
"lastModified": "2026-08-04T11:21:12.547",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D50B3F37-2EA9-4348-B50C-34DCAAF2076E",
"versionEndExcluding": "6.6.57"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "AA84D336-CE9A-4535-B901-1AD77EC17C34",
"versionEndExcluding": "6.11.4",
"versionStartIncluding": "6.7"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}