In the Linux kernel, the following vulnerability has been resolved: ext4: fix memory leak in ext4_fill_super Buffer head references must be released before calling kill_bdev(); otherwise the buffer head (and its page referenced by b_data) will not be freed by kill_bdev, and subsequently that bh will be leaked. If blocksizes differ, sb_set_blocksize() will kill current buffers and page cache by using kill_bdev(). And then super block will be reread again but using correct blocksize this time. sb_set_blocksize() didn't fully free superblock page and buffer head, and being busy, they were not freed and instead leaked. This can easily be reproduced by calling an infinite loop of: systemctl start <ext4_on_lvm>.mount, and systemctl stop <ext4_on_lvm>.mount ... since systemd creates a cgroup for each slice which it mounts, and the bh leak get amplified by a dying memory cgroup that also never gets freed, and memory consumption is much more easily noticed.
History

Mon, 04 Nov 2024 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-03-15T20:14:25.901Z

Updated: 2024-11-04T11:59:46.566Z

Reserved: 2024-03-04T18:12:48.838Z

Link: CVE-2021-47119

cve-icon Vulnrichment

Updated: 2024-08-04T05:24:39.956Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-03-15T21:15:07.013

Modified: 2024-03-17T22:38:29.433

Link: CVE-2021-47119

cve-icon Redhat

Severity : Low

Publid Date: 2024-03-15T00:00:00Z

Links: CVE-2021-47119 - Bugzilla