CVE-2023-53820: loop: loop_set_status_from_info() check before assignment

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-09 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: loop: loop_set_status_from_info() check before assignment In loop_set_status_from_info(), lo->lo_offset and lo->lo_sizelimit should be checked before reassignment, because if an overflow error occurs, the original correct value will be changed to the wrong value, and it will not be changed back. More, the original patch did not solve the problem, the value was set and ioctl returned an error, but the subsequent io used the value in the loop driver, which still caused an alarm: loop_handle_cmd do_req_filebacked loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; lo_rw_aio cmd->iocb.ki_pos = pos

Affected products

Linux kernel: from 4.19.257 before 4.19.312; from 5.4.212 before 5.4.274; from 5.10.140 before 5.10.173; from 5.15.64 before 5.15.100; from 4.9.327 before 4.10; from 4.14.292 before 4.15 — fixed in 4.10, 4.15, 4.19.312, 5.10.173, 5.15.100, 5.20

How to fix

Upgrade to a fixed version: Linux kernel 4.10, 4.15, 4.19.312, 5.10.173. Check the vendor advisory for mitigations.

References

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