Vulnerability record · CVE-2026-98125 · published 25 September 2026
CVE-2026-98125: Linux kernel vulnerability
Linux · Linux Kernel
In the Linux kernel, the following vulnerability has been resolved: smb/client: fix stale page cache in insert/collapse range smb3_insert_range() and smb3_collapse_range() use truncate_pagecache_range() to invalidate the affected page cache. However, if off or old_eof is not page-aligned, the boundary pages are only partially zeroed and remain uptodate. As a result, the client may return stale data after a successful insert/collapse range operation. For example, with 4K pages: page 0 page 1 page 2 0------4K 4K------8K 8K------12K ^ ^ off=2K old_eof=10K Page 1 is removed from the page cache, while the boundary pages are only partially zeroed. After COPYCHUNK moves the data on the server, these cached pages may still return stale data. This can be reproduced on a CIFS mount: bash -c ' FILE=/mnt/scratch/repro # Use a 6 KiB file so EOF is not page-aligned. dd if=/dev/urandom of=/tmp/src bs=1K count=6 status=none # Expected: a 4 KiB hole followed by the original data. rm -f /tmp/expected truncate -s 4K /tmp/expected cat /tmp/src >> /tmp/expected cp /tmp/src "$FILE" # Prime the page cache before moving data on the server. cat "$FILE" > /dev/null fallocate --insert-range -o 0 -l 4K "$FILE" if cmp -s /tmp/expected "$FILE"; then echo "readback: OK" else echo "readback: STALE DATA" fi ' Fix this by writing back dirty data and discarding the page cache from the start of the page containing off to EOF before moving data on the server.
Description
In the Linux kernel, the following vulnerability has been resolved: smb/client: fix stale page cache in insert/collapse range smb3_insert_range() and smb3_collapse_range() use truncate_pagecache_range() to invalidate the affected page cache. However, if off or old_eof is not page-aligned, the boundary pages are only partially zeroed and remain uptodate. As a result, the client may return stale data after a successful insert/collapse range operation. For example, with 4K pages: page 0 page 1 page 2 0------4K 4K------8K 8K------12K ^ ^ off=2K old_eof=10K Page 1 is removed from the page cache, while the boundary pages are only partially zeroed. After COPYCHUNK moves the data on the server, these cached pages may still return stale data. This can be reproduced on a CIFS mount: bash -c ' FILE=/mnt/scratch/repro # Use a 6 KiB file so EOF is not page-aligned. dd if=/dev/urandom of=/tmp/src bs=1K count=6 status=none # Expected: a 4 KiB hole followed by the original data. rm -f /tmp/expected truncate -s 4K /tmp/expected cat /tmp/src >> /tmp/expected cp /tmp/src "$FILE" # Prime the page cache before moving data on the server. cat "$FILE" > /dev/null fallocate --insert-range -o 0 -l 4K "$FILE" if cmp -s /tmp/expected "$FILE"; then echo "readback: OK" else echo "readback: STALE DATA" fi ' Fix this by writing back dirty data and discarding the page cache from the start of the page containing off to EOF before moving data on the server.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-98125), CISA KEV, FIRST EPSS (scores of 2026-11-11). This page is refreshed as NVD updates the record.
