CVE-2026-98124smb/client: invalidate fscache for fallocate range operations
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: smb/client: invalidate fscache for fallocate range operations smb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and smb3_collapse_range() modify file contents through server-side range operations. These operations discard the affected page cache, but leave the FS-Cache cookie valid, so a later read may return data cached before the range operation. Fix this by invalidating FS-Cache after outstanding I/O has completed and before modifying the file on the server. Run the following as root on a CIFS mount with fsc enabled and an active CacheFiles backend: bash -c ' MNT=/mnt/cifs FILE="$MNT/repro" # Generate four 1 MiB random blocks: [A][B][C][D]. dd if=/dev/urandom of=/tmp/src bs=1M count=4 status=none # Expected contents after zeroing B: [A][zero][C][D]. cp /tmp/src /tmp/expected dd if=/dev/zero of=/tmp/expected bs=1M seek=1 count=1 \ conv=notrunc status=none cp /tmp/src "$FILE" # Populate FS-Cache, then discard the page cache. sync echo 1 > /proc/sys/vm/drop_caches cat "$FILE" > /dev/null sync echo 1 > /proc/sys/vm/drop_caches fallocate --zero-range -o 1M -l 1M "$FILE" if cmp -s /tmp/expected "$FILE"; then echo "readback: OK" else echo "readback: STALE DATA" fi ' Before this change, the readback differs from /tmp/expected: readback: STALE DATA After this change, it matches: readback: OK
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 21, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 31742c5a331766bc7df6b0d525df00c6cd20d5a6 before cc7202a51b8777a757bda9dcfbf339f828c6a130; from 31742c5a331766bc7df6b0d525df00c6cd20d5a6 before dd8b1e808f5c19479e6ed47e2f88a1fd46f8b0e5; 31742c5a331766bc7df6b0d525df00c6cd20d5a6 builds before 93c6e5a8d7c5071d586c1411596d5db5faad22b2; 31742c5a331766bc7df6b0d525df00c6cd20d5a6 builds before 448ba0ae65ca61064183564d2983c9aa59bd6ba7 | CNA record |
linux linux_kernel linux:linux_kernel | from 3.17.1 before 6.6.160; from 6.7 before 6.12.114; from 6.13 before 7.2.7; 3.17; 3.17; 3.17; 3.17; 3.17; and 4 more ranges | NVD |
References
- https://git.kernel.org/stable/c/cc7202a51b8777a757bda9dcfbf339f828c6a130patch
- https://git.kernel.org/stable/c/dd8b1e808f5c19479e6ed47e2f88a1fd46f8b0e5patch
- https://git.kernel.org/stable/c/93c6e5a8d7c5071d586c1411596d5db5faad22b2patch
- https://git.kernel.org/stable/c/448ba0ae65ca61064183564d2983c9aa59bd6ba7patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.