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CVE-2026-89634

critical

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix ALIGN() overflow in symlink_data() error context loop The check added by…

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix ALIGN() overflow in symlink_data() error context loop The check added by commit 7d9a7f1f96cd ("smb/client: fix possible infinite loop and oob read in symlink_data()") compared the post-ALIGN length against the remaining buffer, but ALIGN() itself can overflow: for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8) wraps to 0, so the subsequent bounds check passes, and the loop advances by zero bytes leaving 'p' pointing into stale data. Fix by checking the raw ErrorDataLength against the remaining space before applying ALIGN(), then checking again after. Since raw_len is bounded by the buffer, raw_len + 7 cannot overflow, so the second check is an exact post-alignment bounds guard.

CVSS
9.1
9.1 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Severity source: NVD CVSS v3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
Timeline (UTC)
Published: 2026-09-11 20:19
Modified: 2026-10-19 09:18
NVD status: Received
Last synced 1 day ago
Verified against the source API 2026-10-27 06:52 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

Not reported by the source (unknown — not "none").

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:52 UTC · record ↗

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