CVE-2026-31705 (GCVE-0-2026-31705)

Vulnerability from cvelistv5 – Published: 2026-05-01 13:56 – Updated: 2026-05-03 05:45
VLAI?
Title
ksmbd: fix out-of-bounds write in smb2_get_ea() EA alignment
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bounds write in smb2_get_ea() EA alignment smb2_get_ea() applies 4-byte alignment padding via memset() after writing each EA entry. The bounds check on buf_free_len is performed before the value memcpy, but the alignment memset fires unconditionally afterward with no check on remaining space. When the EA value exactly fills the remaining buffer (buf_free_len == 0 after value subtraction), the alignment memset writes 1-3 NUL bytes past the buf_free_len boundary. In compound requests where the response buffer is shared across commands, the first command (e.g., READ) can consume most of the buffer, leaving a tight remainder for the QUERY_INFO EA response. The alignment memset then overwrites past the physical kvmalloc allocation into adjacent kernel heap memory. Add a bounds check before the alignment memset to ensure buf_free_len can accommodate the padding bytes. This is the same bug pattern fixed by commit beef2634f81f ("ksmbd: fix potencial OOB in get_file_all_info() for compound requests") and commit fda9522ed6af ("ksmbd: fix OOB write in QUERY_INFO for compound requests"), both of which added bounds checks before unconditional writes in QUERY_INFO response handlers.
Severity ?
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < ffbce350c6fd1e99116ea57383b9031717e36d3b (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 98f3de6ef4efbd899348d333f0902dc4ff14380c (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 790304c02bf9bd7b8171feda4294d6e62d32ae8f (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 922d48fe8c19f388ffa2f709f33acaae4e408de2 (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 30010c952077a1c89ecdd71fc4d574c75a8f5617 (git)
Affected: f2283680a80571ca82d710bc6ecd8f8beac67d63 (git)
Affected: 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 (git)
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    Linux Linux Affected: 6.6
Unaffected: 0 , < 6.6 (semver)
Unaffected: 6.6.136 , ≤ 6.6.* (semver)
Unaffected: 6.12.84 , ≤ 6.12.* (semver)
Unaffected: 6.18.25 , ≤ 6.18.* (semver)
Unaffected: 7.0.2 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)
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}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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