ext4: use fsdata to track inline data write state and fix race
In the Linux kernel, the following vulnerability has been resolved: ext4: use fsdata to track inline data write state and fix race Instead of checking the live inode state (ext4_has_inline_data(inode) and ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) in the write_end handlers, use the fsdata parameter of the address space operations to explicitly pass down the state in which write_begin prepared the write. A concurrent thread (such as ext4_page_mkwrite()) can convert the inline data to an extent between write_begin and write_end. If this happens, the write_end handlers would previously miss the inline write_end path and fall through to extent-based write_end logic. However, since block buffers were never allocated in write_begin, this resulted in NULL pointer dereferences or data loss because folio_buffers(folio) was NULL. Define EXT4_WRITE_DATA_INLINE (4) as a bit flag (Bit 2), treating fsdata as bitwise flags rather than mutually exclusive enums to keep states of the write path independent. Communicate this state via fsdata: 1) ext4_write_begin() and ext4_da_write_begin() set the EXT4_WRITE_DATA_INLINE bit in *fsdata via bitwise OR when an inline write is successfully prepared. 2) On entry, ext4_write_begin() clears the EXT4_WRITE_DATA_INLINE bit to safely handle VFS retries (where generic_perform_write() bypasses the fsdata initialization on its retry jump). 3) The write_end handlers perform a bitwise AND to check if the EXT4_WRITE_DATA_INLINE bit is set and in
CVE-2026-92500
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-92500
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb",
"lessThan": "bd8d74bd46d09905164255b8635fa58b45f41068",
"versionType": "git"
},
{
"status": "affected",
"version": "3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb",
"lessThan": "439aedfd7ae868d1d7b4930afe66091cb979cd5c",
"versionType": "git"
},
{
"status": "affected",
"version": "3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb",
"lessThan": "7edbb323bab2b2a609016014caafdb651c898249",
"versionType": "git"
}
],
"programFiles": [
"fs/ext4/ext4.h",
"fs/ext4/inline.c",
"fs/ext4/inode.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/ext4/ext4.h",
"fs/ext4/inline.c",
"fs/ext4/inode.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-92500
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #37735 · Revision 1
- Added to Heist Feed
- Publisher date