smb: client: fix ALIGN() overflow in symlink_data() error context loop (Linux Linux)

CVE-2026-89634
CRITICAL 9.1

At a glance

Source
NVD
EPSS
EPSS 0.69 % · percentile 53 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Received

Description

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.

References

Scores

VersionScoreVectorScored by
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HLinux
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

European references

CERT-FR advisories

Affected products

ProductVersions
Linux · Linuxaffected 76894f3e2f71177747b8b4763fb180e800279585 < 2b4a25baa0b936fef6915c0459925077b324ecaf ; affected 76894f3e2f71177747b8b4763fb180e800279585 < b89d678f9eafcf8d74885983166ba26b40a04ea0 ; affected 76894f3e2f71177747b8b4763fb180e800279585 < 657372ba6ea50b4474d2a6a610097eae8cd1f3e9 ; affected 76894f3e2f71177747b8b4763fb180e800279585 < 1f824f61d1df52392eaf0b74dfa5659d724fde30 ; affected 76894f3e2f71177747b8b4763fb180e800279585 < 62a3025983c8c735a3c6fc85a59316f31b59af07 ; affected 76894f3e2f71177747b8b4763fb180e800279585 < 62656b024efc21c3230eade1a847f25871c3d2bb
Linux · Linuxaffected 6.1 ; unaffected 0 < 6.1 ; unaffected 6.1.188 ≤ 6.1.* ; unaffected 6.6.157 ≤ 6.6.* ; unaffected 6.12.109 ≤ 6.12.* ; unaffected 6.18.50 ≤ 6.18.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD