erofs: handle overlapped pclusters out of crafted images properly
In the Linux kernel, the following vulnerability has been resolved: erofs: handle overlapped pclusters out of crafted images properly syzbot reported a task hang issue due to a deadlock case where it is waiting for the folio lock of a cached folio that will be used for cache I/Os. After looking into the crafted fuzzed image, I found it's formed with several overlapped big pclusters as below: Ext: logical offset | length : physical offset | length 0: 0.. 16384 | 16384 : 151552.. 167936 | 16384 1: 16384.. 32768 | 16384 : 155648.. 172032 | 16384 2: 32768.. 49152 | 16384 : 537223168.. 537239552 | 16384 ... Here, extent 0/1 are physically overlapped although it's entirely _impossible_ for normal filesystem images generated by mkfs. First, managed folios containing compressed data will be marked as up-to-date and then unlocked immediately (unlike in-place folios) when compressed I/Os are complete. If physical blocks are not submitted in the incremental order, there should be separate BIOs to avoid dependency issues. However, the current code mis-arranges z_erofs_fill_bio_vec() and BIO submission which causes unexpected BIO waits. Second, managed folios will be connected to their own pclusters for efficient inter-queries. However, this is somewhat hard to implement easily if overlapped big pclusters exist. Again, these only appear in fuzzed images so let's simply fall back to temporary short-lived pages for correctness. Additionally, it justifies that referenced managed folios canno
CVE-2024-47736
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-2024-47736
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": "8e6c8fa9f2e95c88a642521a5da19a8e31748846",
"lessThan": "c1172e65aad4b115392ea4c6e61e56e5b9b69df4",
"versionType": "git"
},
{
"status": "affected",
"version": "8e6c8fa9f2e95c88a642521a5da19a8e31748846",
"lessThan": "1bf7e414cac303c9aec1be67872e19be8b64980c",
"versionType": "git"
},
{
"status": "affected",
"version": "8e6c8fa9f2e95c88a642521a5da19a8e31748846",
"lessThan": "b9b30af0e86ffb485301ecd83b9129c9dfb7ebf8",
"versionType": "git"
},
{
"status": "affected",
"version": "8e6c8fa9f2e95c88a642521a5da19a8e31748846",
"lessThan": "9cfa199bcbbbba31cbf97b2786f44f4464f3f29a",
"versionType": "git"
},
{
"status": "affected",
"version": "8e6c8fa9f2e95c88a642521a5da19a8e31748846",
"lessThan": "9e2f9d34dd12e6e5b244ec488bcebd0c2d566c50",
"versionType": "git"
}
],
"programFiles": [
"fs/erofs/zdata.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.13"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.13",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.168",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.72",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.10.13",
"versionType": "semver",
"lessThanOrEqual": "6.10.*"
},
{
"status": "unaffected",
"version": "6.11.2",
"versionType": "semver",
"lessThanOrEqual": "6.11.*"
},
{
"status": "unaffected",
"version": "6.12",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/erofs/zdata.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2024-47736
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #26740 · Revision 1
- Added to Heist Feed
- Publisher date