CVE-2026-98897

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: don't hold ci->m_lock while waiting for a lease break ack When a cifs.ko client caches a read-handle (RH) lease via deferred close and a conflicting open arrives, ksmbd breaks the lease and waits for the acknowledgment in wait_for_break_ack() for up to OPLOCK_WAIT_TIME (35s). __smb_break_all_levII_oplock() runs that wait while holding ci->m_lock for read. cifs.ko reacts to a handle-lease break by closing the deferred handle rather than sending a lease break acknowledgment. That close path (close_id_del_oplock() -> opinfo_del()) takes ci->m_lock for write and is exactly what would wake the waiter, but it blocks on the read lock held by the waiting thread. The break is then resolved only by the 35s timeout, so xfstests generic/001 takes ~78s with leases enabled versus ~4s with oplocks only. Collect the target opinfos (each pinned with a reference) while holding ci->m_lock, then break them after releasing it, matching how smb_grant_oplock() already breaks a conflicting lease using only a reference. The reference keeps the opinfo (and its conn and lease) alive across the unlocked window, and a close racing the break is handled by the existing OPLOCK_CLOSING state check. Apply the same fix to the parent lease break paths.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-23 12:18:23.670000

Last modified

2026-10-26 07:17:14.980000

View original CVE JSON

{
  "id": "CVE-2026-98897",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T12:18:23.670",
  "lastModified": "2026-10-26T07:17:14.980",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: don't hold ci->m_lock while waiting for a lease break ack\n\nWhen a cifs.ko client caches a read-handle (RH) lease via deferred close\nand a conflicting open arrives, ksmbd breaks the lease and waits for the\nacknowledgment in wait_for_break_ack() for up to OPLOCK_WAIT_TIME (35s).\n__smb_break_all_levII_oplock() runs that wait while holding ci->m_lock\nfor read.\n\ncifs.ko reacts to a handle-lease break by closing the deferred handle\nrather than sending a lease break acknowledgment. That close path\n(close_id_del_oplock() -> opinfo_del()) takes ci->m_lock for write and\nis exactly what would wake the waiter, but it blocks on the read lock\nheld by the waiting thread. The break is then resolved only by the 35s\ntimeout, so xfstests generic/001 takes ~78s with leases enabled versus\n~4s with oplocks only.\n\nCollect the target opinfos (each pinned with a reference) while holding\nci->m_lock, then break them after releasing it, matching how\nsmb_grant_oplock() already breaks a conflicting lease using only a\nreference.  The reference keeps the opinfo (and its conn and lease)\nalive across the unlocked window, and a close racing the break is\nhandled by the existing OPLOCK_CLOSING state check. Apply the same fix\nto the parent lease break paths."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b",
              "lessThan": "868c9038ffd4af39766d087f68c8f543a3f66635",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b",
              "lessThan": "27a9bc968d4ae809a3f5ca2f2b136856ee613cb4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "16ece7c5645a68efca22a0a69a7718c8e50c3232",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6.6.35",
              "lessThan": "6.7",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.9",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.9",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.53",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}