CVE-2026-98682
Received
Received - Intake
Race Condition in Linux Kernel SMB Client Leads to File Corruption
Vulnerability report for CVE-2026-98682, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
smb: client: drain and invalidate before server-side copy/clone
cifs_file_copychunk_range() and the clone (FICLONE) path of
cifs_remap_file_range() do not serialise the destination page cache
against the server-side copy the way the other server-side range
operations (smb3_zero_range(), smb3_punch_hole(), smb3_collapse_range()
and smb3_insert_range()) do.
cifs_file_copychunk_range() invalidates the destination range with
filemap_invalidate_inode(), which takes and drops the mapping's
invalidate_lock internally, so the lock is no longer held when the
copychunk ioctl is issued. It also never drains in-flight netfs I/O on
the target. The clone path never takes the invalidate_lock at all (only
i_rwsem), uses a bare truncate_inode_pages_range() and likewise does not
drain outstanding I/O.
As a result an asynchronous destination writeback can complete after the
server-side copy/clone has run and reinstate stale data over the region
just written by the server, corrupting the file. This is the same class
of corruption as commit d7d2adcd022b ("smb/client: flush dirty data
before punching a hole") and has been seen randomly in generic/363
against Windows Server.
Fix both paths to follow the established ordering: hold the target
mapping's invalidate_lock across the flush and invalidation of the
destination and the server ioctl, and call netfs_wait_for_outstanding_io()
on the target to drain in-flight writes before the ioctl is issued. Only
the target inode's invalidate_lock is required, as the source is merely
flushed and not invalidated; i_rwsem (already held via
lock_two_nondirectories()) is acquired before the invalidate_lock,
matching the VFS lock ordering. Since filemap_invalidate_inode() takes
that same lock internally, replace it with its own unmap/flush/invalidate
steps instead of calling it, and return early on a zero-length copy to
avoid a range underflow.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | c54fc3a4f375663f2361a9cbb2955fb4ef912879 |
| Linux | Linux | c54fc3a4f375663f2361a9cbb2955fb4ef912879 |
| Linux | Linux | 358bd5f436d820bb758833050aae065b35d6986c |
| Linux | Linux | 43801359c8971cc49b4a4db5015fba77fbd09c32 |
| Linux | Linux | 6.1.68 |
| Linux | Linux | 6.6.7 |
| Linux | Linux | 6.7 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
