Memory disclosure and crash via xattr size overflow
Published Apr 18, 2025 · Updated Aug 5, 2026
Out-of-bounds read in JFS extended attributes in Linux allows local users to disclose kernel memory or crash the system via a crafted volume. In ea_get(), an oversized on-disk jfs_ea_list.size value overflows an int clamp, becomes a huge unsigned dump length, and drives hex_dump_to_buffer() beyond the xattr buffer. A crafted JFS volume must be mounted, after which an unprivileged local user with read or search access can trigger the read through an xattr call or ACL lookup, leaking kernel heap data to logs and causing an oops or panic.
Summary
What happened
Out-of-bounds read in JFS extended attributes in Linux allows local users to disclose kernel memory or crash the system via a crafted volume. In ea_get(), an oversized on-disk jfs_ea_list.size value overflows an int clamp, becomes a huge unsigned dump length, and drives hex_dump_to_buffer() beyond the xattr buffer. A crafted JFS volume must be mounted, after which an unprivileged local user with read or search access can trigger the read through an xattr call or ACL lookup, leaking kernel heap data to logs and causing an oops or panic.
The record
- CVE
- CVE-2025-39735
- Published
- Apr 18, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 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
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=27a93c45e16ac25a0e2b5e5668e2d1beca56a478 <78c9cbde8880ec02d864c166bcb4fe989ce1d95f
- Affected versionversion=4.19.325 <4.20
- Affected versionversion=4ea25fa8747fb8b1e5a11d87b852023ecf7ae420
- Affected versionversion=5.10.231 <5.10.236
- Affected versionversion=5.15.174 <5.15.180
- Affected versionversion=5.4.287 <5.4.292
- Affected versionversion=6.11.11 <6.12
- Affected versionversion=6.1.120 <6.1.134
- Affected versionversion=6.12.2 <6.12.23
- Affected versionversion=6.13
- Affected versionversion=6.6.64 <6.6.87
- Affected versionversion=676a787048aafd4d1b38a522b05a9cc77e1b0a33
- Affected versionversion=6e39b681d1eb16f408493bf5023788b57f68998c <3d6fd5b9c6acbc005e53d0211c7381f566babec1
- Affected versionversion=8c505ebeed8045b488b2e60b516c752b851f8437 <0beddc2a3f9b9cf7d8887973041e36c2d0fa3652
- Affected versionversion=9353cdf28d4c5c0ff19c5df7fbf81ea774de43a4 <a8c31808925b11393a6601f534bb63bac5366bab
- Affected versionversion=9c356fc32a4480a2c0e537a05f2a8617633ddad0 <46e2c031aa59ea65128991cbca474bd5c0c2ecdb
- Affected versionversion=bbf3f1fd8a0ac7df1db36a9b9e923041a14369f2 <50afcee7011155933d8d5e8832f52eeee018cfd3
- Affected versionversion=d9f9d96136cba8fedd647d2c024342ce090133c2 <16d3d36436492aa248b2d8045e75585ebcc2f34d
- Affected versionversion=d9f9d96136cba8fedd647d2c024342ce090133c2 <5263822558a8a7c0d0248d5679c2dcf4d5cda61f
- Affected versionversion=d9f9d96136cba8fedd647d2c024342ce090133c2 <fdf480da5837c23b146c4743c18de97202fcab37
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
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo