CVE-2026-89634smb: client: fix ALIGN() overflow in symlink_data() error context loop
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 19, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | 76894f3e2f71177747b8b4763fb180e800279585 builds before 2b4a25baa0b936fef6915c0459925077b324ecaf; from 76894f3e2f71177747b8b4763fb180e800279585 before b89d678f9eafcf8d74885983166ba26b40a04ea0; from 76894f3e2f71177747b8b4763fb180e800279585 before 657372ba6ea50b4474d2a6a610097eae8cd1f3e9; 76894f3e2f71177747b8b4763fb180e800279585 builds before 1f824f61d1df52392eaf0b74dfa5659d724fde30; 76894f3e2f71177747b8b4763fb180e800279585 builds before 62a3025983c8c735a3c6fc85a59316f31b59af07; 76894f3e2f71177747b8b4763fb180e800279585 builds before 62656b024efc21c3230eade1a847f25871c3d2bb; 2d046892a493d9760c35fdaefc3017f27f91b621; from 6.0.16 before 6.1 | CNA record |
References
- https://git.kernel.org/stable/c/2b4a25baa0b936fef6915c0459925077b324ecaf
- https://git.kernel.org/stable/c/b89d678f9eafcf8d74885983166ba26b40a04ea0
- https://git.kernel.org/stable/c/657372ba6ea50b4474d2a6a610097eae8cd1f3e9
- https://git.kernel.org/stable/c/1f824f61d1df52392eaf0b74dfa5659d724fde30
- https://git.kernel.org/stable/c/62a3025983c8c735a3c6fc85a59316f31b59af07
- https://git.kernel.org/stable/c/62656b024efc21c3230eade1a847f25871c3d2bb
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.