CVE-2026-53272: erofs: fix use-after-free on sbi->sync_decompress

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-25 · updated 2026-10-30
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: erofs: fix use-after-free on sbi->sync_decompress z_erofs_decompress_kickoff() can race with filesystem unmount, causing a use-after-free on sbi->sync_decompress. When I/O completes, z_erofs_endio() calls z_erofs_decompress_kickoff() to queue z_erofs_decompressqueue_work() asynchronously. Then, after all folios are unlocked, unmount workflow can proceed and sbi will be freed before accessing to sbi->sync_decompress. Thread (unmount) I/O completion kworker queue_work z_erofs_decompressqueue_work (all folios are unlocked) cleanup_mnt .. erofs_kill_sb erofs_sb_free kfree(sbi) access sbi->sync_decompress // UAF!!

Affected products

Linux kernel: from 5.17 before 6.12.94; from 6.13 before 6.18.36; from 6.19 before 7.0.13; 7.1-rc1, 7.1-rc2, 7.1-rc3, 7.1-rc4, 7.1-rc5, 7.1-rc6 — fixed in 6.12.94, 6.18.36, 7.0.13
Linux: 5.17 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 6.12.94, 6.18.36, 7.0.13; Linux 7.1. Check the vendor advisory for mitigations.

References

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