CVE-2026-31614 (GCVE-0-2026-31614)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:42 – Updated: 2026-05-23 16:05
VLAI
Title
smb: client: fix off-by-8 bounds check in check_wsl_eas()
Summary
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix off-by-8 bounds check in check_wsl_eas() The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA name and value, but ea_data sits at offset sizeof(struct smb2_file_full_ea_info) = 8 from ea, not at offset 0. The strncmp() later reads ea->ea_data[0..nlen-1] and the value bytes follow at ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1 + vlen. Isn't pointer math fun? The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the 8-byte header is in bounds, but since the last EA is placed within 8 bytes of the end of the response, the name and value bytes are read past the end of iov. Fix this mess all up by using ea->ea_data as the base for the bounds check. An "untrusted" server can use this to leak up to 8 bytes of kernel heap into the EA name comparison and influence which WSL xattr the data is interpreted as.
Severity
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 7449d736bbbd160c76b01b8fcdf72f58a8757d4b , < bfbc74df8bbe095b3ed68f6d4487b368af087890 (git)
Affected: ea41367b2a602f602ea6594fc4a310520dcc64f4 , < 5cc0574c84aa73946ade587c41e81757b8b01cb5 (git)
Affected: ea41367b2a602f602ea6594fc4a310520dcc64f4 , < b2b76d09a64c538c57006180103fc1841e8cfa66 (git)
Affected: ea41367b2a602f602ea6594fc4a310520dcc64f4 , < ba3ad159aa61810bbe0acaf39578b1ebfb6f1a18 (git)
Affected: ea41367b2a602f602ea6594fc4a310520dcc64f4 , < a893f1757d9a4009e4a8d7ceb2312142fe29cea4 (git)
Affected: ea41367b2a602f602ea6594fc4a310520dcc64f4 , < 3d8b9d06bd3ac4c6846f5498800b0f5f8062e53b (git)
Affected: 6.6.32 , < 6.6.136 (semver)
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Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.6.136 , ≤ 6.6.* (semver)
Unaffected: 6.12.83 , ≤ 6.12.* (semver)
Unaffected: 6.18.24 , ≤ 6.18.* (semver)
Unaffected: 6.19.14 , ≤ 6.19.* (semver)
Unaffected: 7.0.1 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)
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}


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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.
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