CVE-2026-53038
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
ima_fs: Correctly create securityfs files for unsupported hash algos
ima_tpm_chip->allocated_banks[i].crypto_id is initialized to HASH_ALGO__LAST if the TPM algorithm is not supported. However there are places relying on the algorithm to be valid because it is accessed by hash_algo_name[].
Seems like the TPM chip supports sha3_256, which isn't yet in tpm_algorithms: tpm tpm0: TPM with unsupported bank algorithm 0x0027
That's TPM_ALG_SHA3_256 == 0x0027 from "Trusted Platform Module 2.0 Library Part 2: Structures", page 51 [1]. See also the related U-Boot algorithms update [2].
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Thus solve the problem by creating a file name with "_tpm_alg_<ID>" postfix if the crypto algorithm isn't initialized.
[1]: https://trustedcomputinggroup.org/wp-content/uploads/Trusted-Platform-Module-2.0-Library-Part-2-Version-184_pub.pdf [2]: https://lists.denx.de/pipermail/u-boot/2024-July/558835.html
Detalles técnicos trazas, registros y código del informe original
On 6.12.40 I observe the following read out-of-bounds in hash_algo_name:
==================================================================
BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440
Read of size 8 at addr ffffffff83e18138 by task swapper/0/1
CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3
Call Trace:
<TASK>
dump_stack_lvl+0x61/0x90
print_report+0xc4/0x580
? kasan_addr_to_slab+0x26/0x80
? create_securityfs_measurement_lists+0x396/0x440
kasan_report+0xc2/0x100
? create_securityfs_measurement_lists+0x396/0x440
create_securityfs_measurement_lists+0x396/0x440
ima_fs_init+0xa3/0x300
ima_init+0x7d/0xd0
init_ima+0x28/0x100
do_one_initcall+0xa6/0x3e0
kernel_init_freeable+0x455/0x740
kernel_init+0x24/0x1d0
ret_from_fork+0x38/0x80
ret_from_fork_asm+0x11/0x20
</TASK>
The buggy address belongs to the variable:
hash_algo_name+0xb8/0x420
Memory state around the buggy address:
ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9
^
ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9
ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9
==================================================================
This is how it looks on the test machine (patch ported to v6.12 release):
# ls -1 /sys/kernel/security/ima/
ascii_runtime_measurements
ascii_runtime_measurements_tpm_alg_27
ascii_runtime_measurements_sha1
ascii_runtime_measurements_sha256
binary_runtime_measurements
binary_runtime_measurements_tpm_alg_27
binary_runtime_measurements_sha1
binary_runtime_measurements_sha256
policy
runtime_measurements_count
violationsCVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
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).
Tecnologías afectadas (1)
CWE
- CWE-125
Referencias
JSON original (NVD)
Mostrar
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],
"published": "2026-06-24T17:17:15.403",
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"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-125"
}
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}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nima_fs: Correctly create securityfs files for unsupported hash algos\n\nima_tpm_chip->allocated_banks[i].crypto_id is initialized to\nHASH_ALGO__LAST if the TPM algorithm is not supported. However there\nare places relying on the algorithm to be valid because it is accessed\nby hash_algo_name[].\n\nOn 6.12.40 I observe the following read out-of-bounds in hash_algo_name:\n ==================================================================\n BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440\n Read of size 8 at addr ffffffff83e18138 by task swapper/0/1\n\n CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3\n Call Trace:\n <TASK>\n dump_stack_lvl+0x61/0x90\n print_report+0xc4/0x580\n ? kasan_addr_to_slab+0x26/0x80\n ? create_securityfs_measurement_lists+0x396/0x440\n kasan_report+0xc2/0x100\n ? create_securityfs_measurement_lists+0x396/0x440\n create_securityfs_measurement_lists+0x396/0x440\n ima_fs_init+0xa3/0x300\n ima_init+0x7d/0xd0\n init_ima+0x28/0x100\n do_one_initcall+0xa6/0x3e0\n kernel_init_freeable+0x455/0x740\n kernel_init+0x24/0x1d0\n ret_from_fork+0x38/0x80\n ret_from_fork_asm+0x11/0x20\n </TASK>\n\n The buggy address belongs to the variable:\n hash_algo_name+0xb8/0x420\n\n Memory state around the buggy address:\n ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9\n ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n >ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9\n ^\n ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9\n ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9\n ==================================================================\n\nSeems like the TPM chip supports sha3_256, which isn't yet in\ntpm_algorithms:\n tpm tpm0: TPM with unsupported bank algorithm 0x0027\n\nThat's TPM_ALG_SHA3_256 == 0x0027 from \"Trusted Platform Module 2.0\nLibrary Part 2: Structures\", page 51 [1].\nSee also the related U-Boot algorithms update [2].\n\nThus solve the problem by creating a file name with \"_tpm_alg_<ID>\"\npostfix if the crypto algorithm isn't initialized.\n\nThis is how it looks on the test machine (patch ported to v6.12 release):\n # ls -1 /sys/kernel/security/ima/\n ascii_runtime_measurements\n ascii_runtime_measurements_tpm_alg_27\n ascii_runtime_measurements_sha1\n ascii_runtime_measurements_sha256\n binary_runtime_measurements\n binary_runtime_measurements_tpm_alg_27\n binary_runtime_measurements_sha1\n binary_runtime_measurements_sha256\n policy\n runtime_measurements_count\n violations\n\n[1]: https://trustedcomputinggroup.org/wp-content/uploads/Trusted-Platform-Module-2.0-Library-Part-2-Version-184_pub.pdf\n[2]: https://lists.denx.de/pipermail/u-boot/2024-July/558835.html"
}
],
"lastModified": "2026-07-14T19:36:40.840",
"configurations": [
{
"nodes": [
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}