5.5

CVE-2025-39838

cifs: prevent NULL pointer dereference in UTF16 conversion

In the Linux kernel, the following vulnerability has been resolved:

cifs: prevent NULL pointer dereference in UTF16 conversion

There can be a NULL pointer dereference bug here. NULL is passed to
__cifs_sfu_make_node without checks, which passes it unchecked to
cifs_strndup_to_utf16, which in turn passes it to
cifs_local_to_utf16_bytes where '*from' is dereferenced, causing a crash.

This patch adds a check for NULL 'src' in cifs_strndup_to_utf16 and
returns NULL early to prevent dereferencing NULL pointer.

Found by Linux Verification Center (linuxtesting.org) with SVACE
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 6.12 < 6.12.46
Linux ≫ Linux Kernel Version >= 6.13 < 6.16.6
Linux ≫ Linux Kernel Version6.17 Updaterc1
Linux ≫ Linux Kernel Version6.17 Updaterc2
Linux ≫ Linux Kernel Version6.17 Updaterc3
Linux ≫ Linux Kernel Version6.17 Updaterc4
Debian ≫ Debian Linux Version11.0
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.15% 0.042
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-476 NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

https://git.kernel.org/stable/c/1f797f062b5cf13a1c2bcc23285361baaa7c9260
Patch
https://git.kernel.org/stable/c/3c26a8d30ed6b53a52a023ec537dc50a6d34a67a
Patch
https://git.kernel.org/stable/c/70bccd9855dae56942f2b18a08ba137bb54093a0
Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-032379.html