{"cve":"CVE-2024-47736","nvd":{"published":"2024-10-21T13:15:03.737","modified":"2026-10-15T01:18:57.660","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: handle overlapped pclusters out of crafted images properly\n\nsyzbot reported a task hang issue due to a deadlock case where it is\nwaiting for the folio lock of a cached folio that will be used for\ncache I/Os.\n\nAfter looking into the crafted fuzzed image, I found it's formed with\nseveral overlapped big pclusters as below:\n\n Ext:   logical offset   |  length :     physical offset    |  length\n   0:        0..   16384 |   16384 :     151552..    167936 |   16384\n   1:    16384..   32768 |   16384 :     155648..    172032 |   16384\n   2:    32768..   49152 |   16384 :  537223168.. 537239552 |   16384\n...\n\nHere, extent 0/1 are physically overlapped although it's entirely\n_impossible_ for normal filesystem images generated by mkfs.\n\nFirst, managed folios containing compressed data will be marked as\nup-to-date and then unlocked immediately (unlike in-place folios) when\ncompressed I/Os are complete.  If physical blocks are not submitted in\nthe incremental order, there should be separate BIOs to avoid dependency\nissues.  However, the current code mis-arranges z_erofs_fill_bio_vec()\nand BIO submission which causes unexpected BIO waits.\n\nSecond, managed folios will be connected to their own pclusters for\nefficient inter-queries.  However, this is somewhat hard to implement\neasily if overlapped big pclusters exist.  Again, these only appear in\nfuzzed images so let's simply fall back to temporary short-lived pages\nfor correctness.\n\nAdditionally, it justifies that referenced managed folios cannot be\ntruncated for now and reverts part of commit 2080ca1ed3e4 (\"erofs: tidy\nup `struct z_erofs_bvec`\") for simplicity although it shouldn't be any\ndifference.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/1bf7e414cac303c9aec1be67872e19be8b64980c","https://git.kernel.org/stable/c/9cfa199bcbbbba31cbf97b2786f44f4464f3f29a","https://git.kernel.org/stable/c/9e2f9d34dd12e6e5b244ec488bcebd0c2d566c50","https://git.kernel.org/stable/c/b9b30af0e86ffb485301ecd83b9129c9dfb7ebf8","https://git.kernel.org/stable/c/c1172e65aad4b115392ea4c6e61e56e5b9b69df4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2024-47736","score":0.00182,"percentile":0.07706,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}