Linux hwe edge: In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger When a… (CVE-2026-31718)
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger When a durable file handle survives session disconnect (TCP close without SMB2_LOGOFF), session_fd_check() sets fp->conn = NULL to preserve the handle for later reconnection. However, it did not clean up the byte-range locks on fp->lock_list. Later, when the durable scavenger thread times out and calls __ksmbd_close_fd(NULL, fp), the lock cleanup loop did: spin_lock(&fp->conn->llist_lock); This caused a slab use-after-free because fp->conn was NULL and the original connection object had already been freed by ksmbd_tcp_disconnect(). The root cause is asymmetric cleanup: lock entries (smb_lock->clist) were left dangling on the freed conn->lock_list while fp->conn was nulled out. To fix this issue properly, we need to handle the lifetime of smb_lock->clist across three paths: - Safely skip clist deletion when list is empty and fp->conn is NULL. - Remove the lock from the old connection's lock_list in session_fd_check() - Re-add the lock to the new connection's lock_list in ksmbd_reopen_durable_fd().
Linux hwe edge: In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger When a… (CVE-2026-31718)
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger When a durable file handle survives session disconnect (TCP close without SMB2_LOGOFF), session_fd_check() sets fp->conn = NULL to preserve the handle for later reconnection. However, it did not clean up the byte-range locks on fp->lock_list. Later, when the durable scavenger thread times out and calls __ksmbd_close_fd(NULL, fp), the lock cleanup loop did: spin_lock(&fp->conn->llist_lock); This caused a slab use-after-free because fp->conn was NULL and the original connection object had already been freed by ksmbd_tcp_disconnect(). The root cause is asymmetric cleanup: lock entries (smb_lock->clist) were left dangling on the freed conn->lock_list while fp->conn was nulled out. To fix this issue properly, we need to handle the lifetime of smb_lock->clist across three paths: - Safely skip clist deletion when list is empty and fp->conn is NULL. - Remove the lock from the old connection's lock_list in session_fd_check() - Re-add the lock to the new connection's lock_list in ksmbd_reopen_durable_fd().
CVSS v3.1
Score 9.8critical
Affected software
pkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.2?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.2?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.2?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]+cvm1.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.3?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.2?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.2.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.3?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=bluefield/noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=realtime/noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=realtime/noblepkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resolutepkg:deb/ubuntu/[email protected]?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-31718
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:16.04:LTS","Ubuntu:18.04:LTS","Ubuntu:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:Nvidia-BlueField:24.04:LTS","Ubuntu:Pro:Realtime:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 4.0
Threat ID: 6a58b4cc68715ace43dab03b
Added to database: 07/16/2026, 10:39:08 UTC
Last updated: 07/31/2026, 19:30:30 UTC
Views: 13
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.