Invalid kernel-memory read via unchecked ext4 entry
Published Feb 26, 2025 · Updated Aug 5, 2026
Use-after-free in Linux kernel 3.8 through 5.18.2 allows local users to trigger an invalid kernel-memory read via malformed ext4 data. ext4_get_first_dir_block accepts an oversized rec_len in the first directory entry without validation, so ext4_rename_dir_prepare dereferences an illegal parent entry after its buffer is freed. Reachability requires the kernel to mount crafted ext4 data and process a rename in that malformed directory; the demonstrated consequence is an invalid four-byte kernel-memory read.
Summary
What happened
Use-after-free in Linux kernel 3.8 through 5.18.2 allows local users to trigger an invalid kernel-memory read via malformed ext4 data. ext4_get_first_dir_block accepts an oversized rec_len in the first directory entry without validation, so ext4_rename_dir_prepare dereferences an illegal parent entry after its buffer is freed. Reachability requires the kernel to mount crafted ext4 data and process a rename in that malformed directory; the demonstrated consequence is an invalid four-byte kernel-memory read.
The record
- CVE
- CVE-2022-49349
- Published
- Feb 26, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <0be698ecbe4471fcad80e81ec6a05001421041b3
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <0ff38b99fa075ddd246487a28cb9af049f4ceef1
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <10801095224de0d0ab06ae60698680c1f883a3ae
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <1a3a15bf6f9963d755270cbdb282863b84839195
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <364380c00912bed9b5d99eb485018360b0ecf64f
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <4a2bea60cf7ff957b3eda0b17750d483876a02fa
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <97f802a652a749422dede32071d29a53cf4bd034
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <dd887f83ea54aea5b780a84527e23ab95f777fed
- Affected versionversion=32f7f22c0b52e8189fef83986b16dc7abe95f2c4 <eaecf7ebfd5dd09038a80b14be46b844f54cfc5c
- Affected versionversion=3.8
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Attacks
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