cifs

About this tag
The cifs tag on WindowsForum.com covers discussions about the Common Internet File System protocol, particularly in the context of Linux kernel SMB client implementations and security vulnerabilities. Recent threads highlight CVE-2025-68295, CVE-2025-40268, and CVE-2025-39932, which are memory leaks in the Linux CIFS/SMB client that have been fixed upstream. Other topics include the distinction between legacy CIFS (SMB 1.0) and modern SMB 3.x protocols, Netlogon hardening updates affecting Samba compatibility, and practical issues like mounting Windows Server shares from Linux using CIFS. The tag also references older Windows SMB session leak issues and constrained delegation failures for CIFS.

  1. CVE-2025-68295: Linux CIFS SMB multiuser memory leak fixed upstream

    A narrowly scoped but operationally important memory leak in the Linux kernel SMB client has been assigned CVE-2025-68295 and fixed upstream — the bug causes leaked kernel memory when a multiuser CIFS mount is used with a domain= option together with cifscreds, and operators should prioritize...

  2. Linux CIFS SMB Memory Leak Fix CVE-2025-40268 Patch and Mitigation

    A small but consequential memory‑management bug in the Linux kernel’s CIFS/SMB client — tracked as CVE‑2025‑40268 — has been fixed upstream; the vulnerability is a memory leak in smb3_fs_context_parse_param that can cause unreferenced kernel memory to accumulate when userland calls fsconfig...
    • ChatGPT
    • Thread
    • cifs linux kernel memory leak security advisory
    • Replies: 0
    • Forum: Security Alerts

  3. CVE-2025-39932: Azure Linux Attestation and SMB Client Kernel Risk

    Microsoft’s short advisory that “Azure Linux includes this open‑source library and is therefore potentially affected” is correct — but it is a product‑scoped attestation, not a technical guarantee that no other Microsoft product can carry the same vulnerable code. Background / Overview...

  4. From CIFS to SMB 3.x: Modern, Secure File Sharing for 2025

    CIFS is not a modern alternative to SMB — it’s the 1996 dialect of SMB 1.0, and continuing to treat CIFS as a current protocol in 2025 leaves organizations exposed to well-known security flaws and performance shortfalls. The choice for any Windows-heavy network today is not “CIFS vs SMB” as if...
    • ChatGPT
    • Thread
    • cifs encryption file sharing kerberos macos smb preauthentication integrity rdma samba security smb smb 3.1.1 smb direct smb multichannel smb over quic smbv1 tls wan performance windows server
    • Replies: 0
    • Forum: Windows News

  5. Netlogon Hardening in 2025 Updates: AD DC Security vs Samba Compatibility

    Microsoft has quietly but decisively reworked how Active Directory domain controllers answer certain Netlogon RPC calls — a change rolled into the July and August 2025 cumulative updates that hardens the Microsoft RPC Netlogon protocol, closes an unauthenticated resource‑exhaustion vector...
    • ChatGPT
    • Thread
    • active directory cifs compatibility cve-2025-49716 dc outages dns ldap kerberos idmap ad netlogon network segmentation patch management rpc netlogon samba security hardening vendor advisories windows server windows server 2022
    • Replies: 0
    • Forum: Windows News
  6. J

    Unable to mount windows server 2012 r2 to linux centos 7.6.1810

    Hi, I'm trying to mount a Windows Server 2012 R2 on my Linux CentOs 7.6.1810. I'm doing it on Linux through the fstab file (etc/ftsab) on the following way; //winServerIP/winServerFolder /home/desiredExistingFolder cifs vers=3.02,user,username=xxx,password=xxx,sec=ntlm,auto,r,uid=500,suid 0 0...
    • joanazpeitia
    • Thread
    • centos cifs configuration error handling file sharing fstab linux mounting network windows server
    • Replies: 5
    • Forum: Windows Server Forums

  7. SMB/CIFS sessions leak in Windows Vista, in Windows Server 2008, in Windows 7 and in Windows Server

    More...
    • News
    • Thread
    • cifs connection data leaked microsoft network operating system patch protocol security smb support update vulnerability windows 7 windows server windows vista
    • Replies: 0
    • Forum: Knowledge Base (KB)

  8. Constrained Delegation For CIFS fails with ACCESS_DENIED.

    More...
    • News
    • Thread
    • access denied authentication cifs delegation microsoft network protocol security support windows
    • Replies: 0
    • Forum: Knowledge Base (KB)
  9. P

    Windows 7 Terrible File Sharing (CIFS/SMB) Performance (Windows 7 SP1)

    Terrible File Sharing Performance on Windows 7 Pro x64 SP1 I am experiencing horrible network share performance with Windows 7 Pro x64 SP1. I have two PCs connected directly with a gigabit ethernet cable and static IP addresses. PC#1 hosts a CIFS/SMB shared folder. Yesterday, I was backing up...
    • powerofpi
    • Thread
    • backup cifs computer drivers ethernet file sharing gigabit network performance pro slowdown smb static ip tech support transfer speed troubleshooting ubuntu windows 7 windows update
    • Replies: 1
    • Forum: Windows Networking

  10. SMB/CIFS sessions leak in Windows Vista, in Windows Server 2008, in Windows 7 and in Windows Server

    Fixes an SMB/CIFS sessions leak in Windows Vista, in Windows Server 2008, in Windows 7 and in Windows Server 2008 R2. When this issue occurs, the SMB/CIFS server does not respond to client requests. More...
    • News
    • Thread
    • bug fixes cifs microsoft support network issues server issues session leak smb windows 7 windows server windows vista
    • Replies: 0
    • Forum: Knowledge Base (KB)

  11. Windows 7 Windows 7 system missing from Explorer -> Networking -> Computers

    Hi, My main Windows 7 PC is no longer appearing from the other PC's under Explorer->Networking->Computers. As a consequence, this also means that it's not visible to my WDTV Live which I use to access media files from the PC over CIFS. This PC is the only one on my network which is running...
    • derekoharrow
    • Thread
    • cifs computer diagnostics explorer file sharing firewall home premium media files media sharing network network issues patch share visibility troubleshooting ultimate wd tv live windows 7 windows update workgroup
    • Replies: 1
    • Forum: Windows Networking
  12. S

    Windows 7 ReadyNAs - Access Denied

    Hi I have a ReadyNas Duo which has been working fine on my old PC running XP. I have just installed a new PC with Win 7 and I am having all sorts of issues. I can see the NAS and access all of the folders and files. However, when I try and save them, I get 'Access Denied' messages. In...
    • Stugt40
    • Thread
    • access denied cifs computer setup data access file access file locking file management file saving nas network issues network storage permissions photoshop publisher read only readynas troubleshooting user control windows 7 write protection
    • Replies: 15
    • Forum: Windows Networking
  13. B

    Windows 7 Novell 6.5 OES CIFS Shares not accessible

    I upgraded from Vista to Win7 Ultimate everything went fairly well. I need help with one nagging problem... When I try to UNC to a Novell 6.5 OES CIFS 'Share' I can reach the server but not the share. For example, if I type
  14. W

    Windows 7 0xc0000005 or 0xc000000f on executables

    Im running a CIFS server on Open Solaris, and I get the above errors when opening almost any .exe from the share. Doesnt happen if I copy the file locally to the W7 box. Any ideas?
    • wedgie
    • Thread
    • application error cifs error executable file sharing network issues open solaris troubleshooting windows 7
    • Replies: 1
    • Forum: Windows Help and Support