# CVE-2026-64108: linux: In the Linux kernel, the following vulnerability has been resolved: cifs: Fix busy dentry used after unmounting Sin... CVE-2026-64108 is fixed in 56 products on 1 platform, first by ALAS2023-2026-1882, released June 22, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-64108 - Priority: High - CVSS: 7.8 (high) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 22, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: cifs: Fix busy dentry used after unmounting Since commit 340cea84f691c ("cifs: open files should not hold ref on superblock"), cifs file only holds the dentry ref_cnt, the cifs file close work(cfile->deferred) could be executed after unmounting, which will trigger a warning in generic_shutdown_super: BUG: Dentry 00000000a14a6845{i=c,n=file} still in use (1) [unmount of cifs cifs] The detailed processs is: process A process B kworker fd = open(PATH) vfs_open file->__f_path = *path // dentry->d_lockref.count = 1 cifs_open cifs_new_fileinfo cfile->dentry = dget(dentry) // dentry->d_lockref.count = 2 close(fd) __fput cifs_close queue_delayed_work(deferredclose_wq, cfile->deferred) dput(dentry) // dentry->d_lockref.count = 1 smb2_deferred_work_close _cifsFileInfo_put list_del(&cifs_file->flist) umount cleanup_mnt deactivate_super cifs_kill_sb cifs_close_all_deferred_files_sb cifs_close_all_deferred_files // cannot find cfile, skip _cifsFileInfo_put kill_anon_super generic_shutdown_super shrink_dcache_for_umount umount_check WARN ! // dentry->d_lockref.count = 1 cifsFileInfo_put_final dput(cifs_file->dentry) // dentry->d_lockref.count = 0 Fix it by flushing 'deferredclose_wq' before calling kill_anon_super. Fetch a reproducer in https://bugzilla.kernel.org/show_bug.cgi?id=221548. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | bpftool-debuginfo amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | bpftool6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | bpftool6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-debuginfo amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-debuginfo-common-aarch64 amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-debuginfo-common-x86_64 amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-devel amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-headers amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-livepatch-6.1.175-219.357 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-livepatch-6.12.92-122.166 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel-livepatch-6.18.35-68.127 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel-modules-extra amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-modules-extra-common amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-tools amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-tools-debuginfo amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel-tools-devel amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | kernel6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-devel amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-headers amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-tools amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.176-1 | [DEBIAN-CVE-2026-64108](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64108.md) | Jul 20, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.94-1 | [DEBIAN-CVE-2026-64108](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64108.md) | Jul 20, 2026 | | Linux | linux Debian 14 | 7.0.12-1 | [DEBIAN-CVE-2026-64108](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64108.md) | Jul 20, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | perf amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | perf-debuginfo amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | perf6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | python3-perf amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | python3-perf-debuginfo amzn 2023 | 1:6.1.175-219.357.amzn2023 | [ALAS2023-2026-1882](https://patchblox.com/security/data/fix/linux/alas2023-2026-1882.md) | Jun 22, 2026 | | Linux | python3-perf6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | --- Data as of 2026-11-08T19:12:23Z UTC. 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