vulnerability

Ubuntu: (Multiple Advisories) (CVE-2024-47736): Linux kernel vulnerabilities

Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
Oct 21, 2024
Added
Feb 20, 2025
Modified
Aug 18, 2025

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.

Solutions

ubuntu-upgrade-linux-image-6-11-0-1005-realtimeubuntu-upgrade-linux-image-6-11-0-1008-raspiubuntu-upgrade-linux-image-6-11-0-1009-awsubuntu-upgrade-linux-image-6-11-0-1009-azureubuntu-upgrade-linux-image-6-11-0-1009-azure-fdeubuntu-upgrade-linux-image-6-11-0-1009-gcpubuntu-upgrade-linux-image-6-11-0-1010-lowlatencyubuntu-upgrade-linux-image-6-11-0-1010-lowlatency-64kubuntu-upgrade-linux-image-6-11-0-1011-oracleubuntu-upgrade-linux-image-6-11-0-1011-oracle-64kubuntu-upgrade-linux-image-6-11-0-1015-oemubuntu-upgrade-linux-image-6-11-0-18-genericubuntu-upgrade-linux-image-6-11-0-18-generic-64kubuntu-upgrade-linux-image-6-8-0-1012-gkeopubuntu-upgrade-linux-image-6-8-0-1016-azure-nvidiaubuntu-upgrade-linux-image-6-8-0-1025-gkeubuntu-upgrade-linux-image-6-8-0-1026-ibmubuntu-upgrade-linux-image-6-8-0-1026-oracleubuntu-upgrade-linux-image-6-8-0-1026-oracle-64kubuntu-upgrade-linux-image-6-8-0-1028-nvidiaubuntu-upgrade-linux-image-6-8-0-1028-nvidia-64kubuntu-upgrade-linux-image-6-8-0-1028-nvidia-lowlatencyubuntu-upgrade-linux-image-6-8-0-1028-nvidia-lowlatency-64kubuntu-upgrade-linux-image-6-8-0-1028-oemubuntu-upgrade-linux-image-6-8-0-1028-raspiubuntu-upgrade-linux-image-6-8-0-1029-awsubuntu-upgrade-linux-image-6-8-0-1029-azureubuntu-upgrade-linux-image-6-8-0-1029-azure-fdeubuntu-upgrade-linux-image-6-8-0-1030-gcpubuntu-upgrade-linux-image-6-8-0-1030-gcp-64kubuntu-upgrade-linux-image-6-8-0-2023-raspi-realtimeubuntu-upgrade-linux-image-6-8-0-60-genericubuntu-upgrade-linux-image-6-8-0-60-generic-64kubuntu-upgrade-linux-image-6-8-0-60-lowlatencyubuntu-upgrade-linux-image-6-8-0-60-lowlatency-64kubuntu-upgrade-linux-image-6-8-1-1022-realtimeubuntu-upgrade-linux-image-awsubuntu-upgrade-linux-image-aws-lts-24-04ubuntu-upgrade-linux-image-azureubuntu-upgrade-linux-image-azure-fdeubuntu-upgrade-linux-image-azure-fde-lts-24-04ubuntu-upgrade-linux-image-azure-lts-24-04ubuntu-upgrade-linux-image-azure-nvidiaubuntu-upgrade-linux-image-gcpubuntu-upgrade-linux-image-gcp-64kubuntu-upgrade-linux-image-gcp-64k-lts-24-04ubuntu-upgrade-linux-image-gcp-lts-24-04ubuntu-upgrade-linux-image-genericubuntu-upgrade-linux-image-generic-64kubuntu-upgrade-linux-image-generic-64k-hwe-22-04ubuntu-upgrade-linux-image-generic-64k-hwe-24-04ubuntu-upgrade-linux-image-generic-hwe-22-04ubuntu-upgrade-linux-image-generic-hwe-24-04ubuntu-upgrade-linux-image-generic-lpaeubuntu-upgrade-linux-image-gkeubuntu-upgrade-linux-image-gkeopubuntu-upgrade-linux-image-gkeop-6-8ubuntu-upgrade-linux-image-ibmubuntu-upgrade-linux-image-ibm-classicubuntu-upgrade-linux-image-ibm-lts-24-04ubuntu-upgrade-linux-image-kvmubuntu-upgrade-linux-image-lowlatencyubuntu-upgrade-linux-image-lowlatency-64kubuntu-upgrade-linux-image-lowlatency-64k-hwe-22-04ubuntu-upgrade-linux-image-lowlatency-hwe-22-04ubuntu-upgrade-linux-image-nvidiaubuntu-upgrade-linux-image-nvidia-6-8ubuntu-upgrade-linux-image-nvidia-64kubuntu-upgrade-linux-image-nvidia-64k-6-8ubuntu-upgrade-linux-image-nvidia-64k-hwe-22-04ubuntu-upgrade-linux-image-nvidia-hwe-22-04ubuntu-upgrade-linux-image-nvidia-lowlatencyubuntu-upgrade-linux-image-nvidia-lowlatency-64kubuntu-upgrade-linux-image-oem-22-04ubuntu-upgrade-linux-image-oem-22-04aubuntu-upgrade-linux-image-oem-22-04bubuntu-upgrade-linux-image-oem-22-04cubuntu-upgrade-linux-image-oem-22-04dubuntu-upgrade-linux-image-oem-24-04ubuntu-upgrade-linux-image-oem-24-04aubuntu-upgrade-linux-image-oem-24-04bubuntu-upgrade-linux-image-oracleubuntu-upgrade-linux-image-oracle-64kubuntu-upgrade-linux-image-oracle-64k-lts-24-04ubuntu-upgrade-linux-image-oracle-lts-24-04ubuntu-upgrade-linux-image-raspiubuntu-upgrade-linux-image-raspi-realtimeubuntu-upgrade-linux-image-realtimeubuntu-upgrade-linux-image-realtime-hwe-24-04ubuntu-upgrade-linux-image-virtualubuntu-upgrade-linux-image-virtual-hwe-22-04ubuntu-upgrade-linux-image-virtual-hwe-24-04

References

    Title
    NEW

    Explore Exposure Command

    Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.