erofs: fix crafted invalid cases for encoded extents
Robert recently reported two corrupted images that can cause system
crashes, which are related to the new encoded extents introduced
in Linux 6.15:
- The first one [1] has plen != 0 (e.g. plen == 0x2000000) but
(plen & Z_EROFS_EXTENT_PLEN_MASK) == 0. It is used to represent
special extents such as sparse extents (!EROFS_MAP_MAPPED), but
previously only plen == 0 was handled;
- The second one [2] has pa 0xffffffffffdcffed and plen 0xb4000,
then "cur [0xfffffffffffff000] += bvec.bv_len [0x1000]" in
"} while ((cur += bvec.bv_len) < end);" wraps around, causing an
out-of-bound access of pcl->compressed_bvecs[] in
z_erofs_submit_queue(). EROFS only supports 48-bit physical block
addresses (up to 1EiB for 4k blocks), so add a sanity check to
enforce this.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
| Source | ID | Title |
|---|---|---|
 Ubuntu USN |
USN-8029-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-8030-1 | Linux kernel (GCP) vulnerabilities |
| Ubuntu USN |
USN-8029-2 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-8048-1 | Linux kernel (OEM) vulnerabilities |
| Ubuntu USN |
USN-8029-3 | Linux kernel (Azure) vulnerabilities |
Sat, 06 Dec 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Thu, 04 Dec 2025 15:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: erofs: fix crafted invalid cases for encoded extents Robert recently reported two corrupted images that can cause system crashes, which are related to the new encoded extents introduced in Linux 6.15: - The first one [1] has plen != 0 (e.g. plen == 0x2000000) but (plen & Z_EROFS_EXTENT_PLEN_MASK) == 0. It is used to represent special extents such as sparse extents (!EROFS_MAP_MAPPED), but previously only plen == 0 was handled; - The second one [2] has pa 0xffffffffffdcffed and plen 0xb4000, then "cur [0xfffffffffffff000] += bvec.bv_len [0x1000]" in "} while ((cur += bvec.bv_len) < end);" wraps around, causing an out-of-bound access of pcl->compressed_bvecs[] in z_erofs_submit_queue(). EROFS only supports 48-bit physical block addresses (up to 1EiB for 4k blocks), so add a sanity check to enforce this. | |
| Title | erofs: fix crafted invalid cases for encoded extents | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T21:45:31.323Z
Reserved: 2025-04-16T07:20:57.181Z
Link: CVE-2025-40241
Vulnrichment
No data.
NVD
Status : Deferred
Published: 2025-12-04T16:16:17.250
Modified: 2026-04-15T00:35:42.020
Link: CVE-2025-40241
Redhat
OpenCVE Enrichment
No data.
No weakness.