{"id":"CVE-2026-98124","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: invalidate fscache for fallocate range operations\n\nsmb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and\nsmb3_collapse_range() modify file contents…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: invalidate fscache for fallocate range operations\n\nsmb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and\nsmb3_collapse_range() modify file contents…","severity":"medium","vendor":"Linux","product":"Linux","affected":["Linux >= 31742c5a331766bc7df6b0d525df00c6cd20d5a6 < 93c6e5a8d7c5071d586c1411596d5db5faad22b2","Linux >= 31742c5a331766bc7df6b0d525df00c6cd20d5a6 < 448ba0ae65ca61064183564d2983c9aa59bd6ba7","Linux 3.17"],"published":"2026-09-25","updated":"2026-09-30","sourceUpdated":"2026-09-30T14:10:59.253","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98124","references":[{"url":"https://git.kernel.org/stable/c/448ba0ae65ca61064183564d2983c9aa59bd6ba7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/93c6e5a8d7c5071d586c1411596d5db5faad22b2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98124.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98124"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541341"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98124"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98124"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98124.mbox"},{"url":"https://git.kernel.org/stable/c/cc7202a51b8777a757bda9dcfbf339f828c6a130"},{"url":"https://git.kernel.org/stable/c/dd8b1e808f5c19479e6ed47e2f88a1fd46f8b0e5"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00186,"epssPercentile":0.08102,"ingestedAt":"2026-09-25T11:06:38.819Z","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-524"],"slug":"CVE-2026-98124","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: invalidate fscache for fallocate range operations\n\nsmb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and\nsmb3_collapse_range() modify file contents through server-side range\noperations. These operations discard the affected page cache, but leave\nthe FS-Cache cookie valid, so a later read may return data cached before\nthe range operation.\n\nFix this by invalidating FS-Cache after outstanding I/O has completed\nand before modifying the file on the server.\n\nRun the following as root on a CIFS mount with fsc enabled and an active\nCacheFiles backend:\n\n        bash -c '\n                MNT=/mnt/cifs\n                FILE=\"$MNT/repro\"\n\n                # Generate four 1 MiB random blocks: [A][B][C][D].\n                dd if=/dev/urandom of=/tmp/src bs=1M count=4 status=none\n\n                # Expected contents after zeroing B: [A][zero][C][D].\n                cp /tmp/src /tmp/expected\n                dd if=/dev/zero of=/tmp/expected bs=1M seek=1 count=1 \\\n                        conv=notrunc status=none\n                cp /tmp/src \"$FILE\"\n\n                # Populate FS-Cache, then discard the page cache.\n                sync\n                echo 1 > /proc/sys/vm/drop_caches\n                cat \"$FILE\" > /dev/null\n                sync\n                echo 1 > /proc/sys/vm/drop_caches\n\n                fallocate --zero-range -o 1M -l 1M \"$FILE\"\n\n                if cmp -s /tmp/expected \"$FILE\"; then\n                        echo \"readback: OK\"\n                else\n                        echo \"readback: STALE DATA\"\n                fi\n        '\n\nBefore this change, the readback differs from /tmp/expected:\n\n        readback: STALE DATA\n\nAfter this change, it matches:\n\n        readback: OK\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98124.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224151,"id":"CVE-2026-98124","ts":1792324963676,"field":"cvss","old":null,"new":"5.5"},{"seq":224150,"id":"CVE-2026-98124","ts":1792324963676,"field":"severity","old":"none","new":"medium"}]}