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GHSA-48V3-JVQ8-5VJP

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

cifs: remove all cifs files before kill super

Cifs files may be put into fileinfo_put_wq during umounting cifs. After umount done, cifsFileInfo_put_final is called, which cause following BUG:

BUG: kernel NULL pointer dereference, address: 0000000000000000 ... [ 134.222152] list_lru_add+0x64/0x1a0 [ 134.222399] ? cifs_put_tcon+0x171/0x340 [cifs] [ 134.222772] d_lru_add+0x44/0x60 [ 134.222997] dput+0x1fc/0x210 [ 134.223213] cifsFileInfo_put_final+0x11a/0x140 [cifs] [ 134.223576] process_one_work+0x17c/0x320 [ 134.223843] worker_thread+0x188/0x280 [ 134.224084] ? __pfx_worker_thread+0x10/0x10 [ 134.224366] kthread+0xcc/0x100 [ 134.224576] ? __pfx_kthread+0x10/0x10 [ 134.224827] ret_from_fork+0x30/0x50 [ 134.225063] ? __pfx_kthread+0x10/0x10 [ 134.225328] ret_from_fork_asm+0x1b/0x30

This can be reproduce by following: unshare -n bash -c " mkdir -p ${CIFS_MNT} ip netns attach root 1 ip link add eth0 type veth peer veth0 netns root ip link set eth0 up ip -n root link set veth0 up ip addr add 192.168.0.2/24 dev eth0 ip -n root addr add 192.168.0.1/24 dev veth0 ip route add default via 192.168.0.1 dev eth0 ip netns exec root sysctl net.ipv4.ip_forward=1 ip netns exec root iptables -t nat -A POSTROUTING -s 192.168.0.2 -o ${DEV} -j MASQUERADE mount -t cifs ${CIFS_PATH} ${CIFS_MNT} -o vers=3.0,sec=ntlmssp,credentials=${CIFS_CRED},rsize=65536,wsize=65536,cache=none,echo_interval=1 touch ${CIFS_MNT}/a.txt ip netns exec root iptables -t nat -D POSTROUTING -s 192.168.0.2 -o ${DEV} -j MASQUERADE " umount ${CIFS_MNT}

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-74259"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:25Z",
    "severity": "HIGH"
  },
  "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}",
  "id": "GHSA-48v3-jvq8-5vjp",
  "modified": "2026-08-17T06:33:34Z",
  "published": "2026-08-15T06:32:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74259"
    },
    {
      "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"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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