Kernel memory disclosure and panic via readdir race
Published Jun 18, 2025 · Updated Aug 5, 2026
Use-after-free in the Linux kernel SMB client allows local users to disclose kernel memory or crash the host via concurrent directory reads. The cifs_readdir path can free the response buffer while another directory reader continues into cifs_fill_dirent, which dereferences stale srch_inf pointers. An unprivileged local account needs read access to an existing CIFS mount; exploitation can leak freed kernel heap data, corrupt kernel memory, or panic the host.
Summary
What happened
Use-after-free in the Linux kernel SMB client allows local users to disclose kernel memory or crash the host via concurrent directory reads. The cifs_readdir path can free the response buffer while another directory reader continues into cifs_fill_dirent, which dereferences stale srch_inf pointers. An unprivileged local account needs read access to an existing CIFS mount; exploitation can leak freed kernel heap data, corrupt kernel memory, or panic the host.
The record
- CVE
- CVE-2025-38051
- Published
- Jun 18, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 18, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0f3da51e7046e2eb28992ba65c22d058f571356c
- Affected versionversion=2.6.27.4 <2.6.28
- Affected versionversion=2.6.28
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <1b197931fbc821bc7e9e91bf619400db563e3338
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <73cadde98f67f76c5eba00ac0b72c453383cec8b
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <9bea368648ac46f8593a780760362e40291d22a9
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <9c9aafbacc183598f064902365e107b5e856531f
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <a24c2f05ac3c5b0aaa539d9d913826d2643dfd0e
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <a7a8fe56e932a36f43e031b398aef92341bf5ea0
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <aee067e88d61eb72e966f094e4749c6b14e7008f
- Affected versionversion=a364bc0b37f14ffd66c1f982af42990a9d77fa43 <c8623231e0edfcccb7cc6add0288fa0f0594282f
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream CIFS readdir race proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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