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CVE-2026-31610

Опубликовано: 24 апр. 2026
Источник: nvd
CVSS3: 5.5
EPSS Низкий

Описание

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc

The kernel ASN.1 BER decoder calls action callbacks incrementally as it walks the input. When ksmbd_decode_negTokenInit() reaches the mechToken [2] OCTET STRING element, ksmbd_neg_token_alloc() allocates conn->mechToken immediately via kmemdup_nul(). If a later element in the same blob is malformed, then the decoder will return nonzero after the allocation is already live. This could happen if mechListMIC [3] overrunse the enclosing SEQUENCE.

decode_negotiation_token() then sets conn->use_spnego = false because both the negTokenInit and negTokenTarg grammars failed. The cleanup at the bottom of smb2_sess_setup() is gated on use_spnego:

if (conn->use_spnego && conn->mechToken) { kfree(conn->mechToken); conn->mechToken = NULL; }

so the kfree is skipped, causing the mechToken to never be freed.

This codepath is reachable pre-authenticatio

Уязвимые конфигурации

Конфигурация 1

Одно из

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 5.15 (включая) до 6.6.136 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.7 (включая) до 6.12.83 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.13 (включая) до 6.18.24 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.19 (включая) до 6.19.14 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 7.0 (включая) до 7.0.1 (исключая)

EPSS

Процентиль: 3%
0.00136
Низкий

5.5 Medium

CVSS3

Дефекты

CWE-401

Связанные уязвимости

CVSS3: 5.5
ubuntu
4 месяца назад

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc The kernel ASN.1 BER decoder calls action callbacks incrementally as it walks the input. When ksmbd_decode_negTokenInit() reaches the mechToken [2] OCTET STRING element, ksmbd_neg_token_alloc() allocates conn->mechToken immediately via kmemdup_nul(). If a later element in the same blob is malformed, then the decoder will return nonzero after the allocation is already live. This could happen if mechListMIC [3] overrunse the enclosing SEQUENCE. decode_negotiation_token() then sets conn->use_spnego = false because both the negTokenInit and negTokenTarg grammars failed. The cleanup at the bottom of smb2_sess_setup() is gated on use_spnego: if (conn->use_spnego && conn->mechToken) { kfree(conn->mechToken); conn->mechToken = NULL; } so the kfree is skipped, causing the mechToken to never be freed. This codepath is reachable pre-authentication, so unt...

redhat
4 месяца назад

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc The kernel ASN.1 BER decoder calls action callbacks incrementally as it walks the input. When ksmbd_decode_negTokenInit() reaches the mechToken [2] OCTET STRING element, ksmbd_neg_token_alloc() allocates conn->mechToken immediately via kmemdup_nul(). If a later element in the same blob is malformed, then the decoder will return nonzero after the allocation is already live. This could happen if mechListMIC [3] overrunse the enclosing SEQUENCE. decode_negotiation_token() then sets conn->use_spnego = false because both the negTokenInit and negTokenTarg grammars failed. The cleanup at the bottom of smb2_sess_setup() is gated on use_spnego: if (conn->use_spnego && conn->mechToken) { kfree(conn->mechToken); conn->mechToken = NULL; } so the kfree is skipped, causing the mechToken to never be freed. This codepath is reachable pre-authentication, so unt...

msrc
3 месяца назад

ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc

CVSS3: 5.5
debian
4 месяца назад

In the Linux kernel, the following vulnerability has been resolved: k ...

CVSS3: 5.5
github
4 месяца назад

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc The kernel ASN.1 BER decoder calls action callbacks incrementally as it walks the input. When ksmbd_decode_negTokenInit() reaches the mechToken [2] OCTET STRING element, ksmbd_neg_token_alloc() allocates conn->mechToken immediately via kmemdup_nul(). If a later element in the same blob is malformed, then the decoder will return nonzero after the allocation is already live. This could happen if mechListMIC [3] overrunse the enclosing SEQUENCE. decode_negotiation_token() then sets conn->use_spnego = false because both the negTokenInit and negTokenTarg grammars failed. The cleanup at the bottom of smb2_sess_setup() is gated on use_spnego: if (conn->use_spnego && conn->mechToken) { kfree(conn->mechToken); conn->mechToken = NULL; } so the kfree is skipped, causing the mechToken to never be freed. This codepath is reachable pre-authentica...

EPSS

Процентиль: 3%
0.00136
Низкий

5.5 Medium

CVSS3

Дефекты

CWE-401