CVE-2024-47736erofs: handle overlapped pclusters out of crafted images properly
- 5.5MediumCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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 cannot be truncated for now and reverts part of commit 2080ca1ed3e4 ("erofs: tidy up `struct z_erofs_bvec`") for simplicity although it shouldn't be any difference.
Timeline
ID reserved
By Linux
- 21 days later
· 21 days later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 8e6c8fa9f2e95c88a642521a5da19a8e31748846 – < c1172e65aad4b115392ea4c6e61e56e5b9b69df4
- affected 8e6c8fa9f2e95c88a642521a5da19a8e31748846 – < 1bf7e414cac303c9aec1be67872e19be8b64980c
- affected 8e6c8fa9f2e95c88a642521a5da19a8e31748846 – < b9b30af0e86ffb485301ecd83b9129c9dfb7ebf8
- affected 8e6c8fa9f2e95c88a642521a5da19a8e31748846 – < 9cfa199bcbbbba31cbf97b2786f44f4464f3f29a
- affected 8e6c8fa9f2e95c88a642521a5da19a8e31748846 – < 9e2f9d34dd12e6e5b244ec488bcebd0c2d566c50
- affected 5.13
- unaffected < 5.13
- unaffected 6.1.168 – ≤ 6.1.*
- unaffected 6.6.72 – ≤ 6.6.*
- unaffected 6.10.13 – ≤ 6.10.*
- unaffected 6.11.2 – ≤ 6.11.*
- unaffected 6.12 – ≤ *
References
References8
- https://git.kernel.org/stable/c/c1172e65aad4b115392ea4c6e61e56e5b9b69df4 (opens in a new tab)
- https://git.kernel.org/stable/c/1bf7e414cac303c9aec1be67872e19be8b64980c (opens in a new tab)
- https://git.kernel.org/stable/c/b9b30af0e86ffb485301ecd83b9129c9dfb7ebf8 (opens in a new tab)
- https://git.kernel.org/stable/c/9cfa199bcbbbba31cbf97b2786f44f4464f3f29a (opens in a new tab)
- https://git.kernel.org/stable/c/9e2f9d34dd12e6e5b244ec488bcebd0c2d566c50 (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2024-42870 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2024-47736)Record last updated .