CVE-2021-47119 (GCVE-0-2021-47119)

Vulnerability from cvelistv5 – Published: 2024-03-15 20:14 – Updated: 2025-05-04 07:04
VLAI?
Title
ext4: fix memory leak in ext4_fill_super
Summary
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.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: ac27a0ec112a089f1a5102bc8dffc79c8c815571 , < 01d349a481f0591230300a9171330136f9159bcd (git)
Affected: ac27a0ec112a089f1a5102bc8dffc79c8c815571 , < 1385b23396d511d5233b8b921ac3058b3f86a5e1 (git)
Affected: ac27a0ec112a089f1a5102bc8dffc79c8c815571 , < afd09b617db3786b6ef3dc43e28fe728cfea84df (git)
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    Linux Linux Affected: 2.6.19
Unaffected: 0 , < 2.6.19 (semver)
Unaffected: 5.10.43 , ≤ 5.10.* (semver)
Unaffected: 5.12.10 , ≤ 5.12.* (semver)
Unaffected: 5.13 , ≤ * (original_commit_for_fix)
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