CVE-2021-47119
Vulnerability from cvelistv5
Published
2024-03-15 20:14
Modified
2024-12-19 07:35
Severity ?
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/01d349a481f0591230300a9171330136f9159bcdPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1385b23396d511d5233b8b921ac3058b3f86a5e1Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/afd09b617db3786b6ef3dc43e28fe728cfea84dfPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/01d349a481f0591230300a9171330136f9159bcdPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/1385b23396d511d5233b8b921ac3058b3f86a5e1Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/afd09b617db3786b6ef3dc43e28fe728cfea84dfPatch
Impacted products
Vendor Product Version
Linux Linux Version: ac27a0ec112a089f1a5102bc8dffc79c8c815571
Version: ac27a0ec112a089f1a5102bc8dffc79c8c815571
Version: ac27a0ec112a089f1a5102bc8dffc79c8c815571
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   Linux Linux Version: 2.6.19
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