{"id":"CVE-2026-74259","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74259","summary":"cifs: remove all cifs files before kill super","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: remove all cifs files before kill super\n\nCifs files may be put into fileinfo_put_wq during umounting cifs.\nAfter umount done, cifsFileInfo_put_final is called, which cause\nfollowing BUG:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n...\n[  134.222152]  list_lru_add+0x64/0x1a0\n[  134.222399]  ? cifs_put_tcon+0x171/0x340 [cifs]\n[  134.222772]  d_lru_add+0x44/0x60\n[  134.222997]  dput+0x1fc/0x210\n[  134.223213]  cifsFileInfo_put_final+0x11a/0x140 [cifs]\n[  134.223576]  process_one_work+0x17c/0x320\n[  134.223843]  worker_thread+0x188/0x280\n[  134.224084]  ? __pfx_worker_thread+0x10/0x10\n[  134.224366]  kthread+0xcc/0x100\n[  134.224576]  ? __pfx_kthread+0x10/0x10\n[  134.224827]  ret_from_fork+0x30/0x50\n[  134.225063]  ? __pfx_kthread+0x10/0x10\n[  134.225328]  ret_from_fork_asm+0x1b/0x30\n\nThis can be reproduce by following:\nunshare -n bash -c \"\nmkdir -p ${CIFS_MNT}\nip netns attach root 1\nip link add eth0 type veth peer veth0 netns root\nip link set eth0 up\nip -n root link set veth0 up\nip addr add 192.168.0.2/24 dev eth0\nip -n root addr add 192.168.0.1/24 dev veth0\nip route add default via 192.168.0.1 dev eth0\nip netns exec root sysctl net.ipv4.ip_forward=1\nip netns exec root iptables -t nat -A POSTROUTING -s 192.168.0.2 -o\n${DEV} -j MASQUERADE\nmount -t cifs ${CIFS_PATH} ${CIFS_MNT} -o\nvers=3.0,sec=ntlmssp,credentials=${CIFS_CRED},rsize=65536,wsize=65536,cache=none,echo_interval=1\ntouch ${CIFS_MNT}/a.txt\nip netns exec root iptables -t nat -D POSTROUTING -s 192.168.0.2 -o\n${DEV} -j MASQUERADE\n\"\numount ${CIFS_MNT}","published":"2026-08-15T05:57:36.937Z","modified":"2026-08-18T03:56:28.353513002Z","cvss":{"score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.1.178"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/21303c4a2b7275e626c6b67de0f45f2d5b9bb3e7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3baedc9b2f53e6a6ac57b16fdff0f9b954d9ca71"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4465ebe67d89345954bb3622b25dd13e06f9d367"},{"type":"WEB","url":"https://git.kernel.org/stable/c/55fb9581986141659002264fdc75cef307811eb8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6d9a4aaaa8b2612b5ef9d581e2f286a458b71ee1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7839f1817a0cb6c4ed5cfe25d04845c43380a129"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74259.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74259"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:28.353513002Z"}}