CVE-2023-53783

blk-iocost: fix divide by 0 error in calc_lcoefs()

State: Published
Severity: Not scored
Published: Dec 9, 2025
Updated: May 11, 2026
Reserved: Dec 8, 2025

Description

In the Linux kernel, the following vulnerability has been resolved:

blk-iocost: fix divide by 0 error in calc_lcoefs()

echo max of u64 to cost.model can cause divide by 0 error.

# echo 8:0 rbps=18446744073709551615 > /sys/fs/cgroup/io.cost.model

divide error: 0000 [#1] PREEMPT SMP RIP: 0010:calc_lcoefs+0x4c/0xc0 Call Trace: <TASK> ioc_refresh_params+0x2b3/0x4f0 ioc_cost_model_write+0x3cb/0x4c0 ? _copy_from_iter+0x6d/0x6c0 ? kernfs_fop_write_iter+0xfc/0x270 cgroup_file_write+0xa0/0x200 kernfs_fop_write_iter+0x17d/0x270 vfs_write+0x414/0x620 ksys_write+0x73/0x160 __x64_sys_write+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd

calc_lcoefs() uses the input value of cost.model in DIV_ROUND_UP_ULL, overflow would happen if bps plus IOC_PAGE_SIZE is greater than ULLONG_MAX, it can cause divide by 0 error.

Fix the problem by setting basecost

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 9e8bf9f95f7a299fa9ea45b678d001806ad5e12cAffected 7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 6e291810fe83a384700eb24a1f714966391ed562Affected 7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 3538ade9d8c2ba41088e395de916f2599fadba8fAffected 7caa47151ab2e644dd221f741ec7578d9532c9a3 to before bf8eb1fd6110871e6232e8e7efe399276ef7e6f6Affected 7caa47151ab2e644dd221f741ec7578d9532c9a3 to before b96d7b4a9745fbd0c8384608ceb1f50415e862faAffected 7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 984af1e66b4126cf145153661cc24c213e2ec231Affected
LinuxLinux	5.4Affected before 5.4Not affected 5.4.235 through 5.4.Not affected 5.10.173 through 5.10.Not affected 5.15.99 through 5.15.Not affected 6.1.16 through 6.1.Not affected 6.2.3 through 6.2.*Not affected 6.3 and laterNot affected

Product

Versions

LinuxLinux

7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 9e8bf9f95f7a299fa9ea45b678d001806ad5e12cAffected
7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 6e291810fe83a384700eb24a1f714966391ed562Affected
7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 3538ade9d8c2ba41088e395de916f2599fadba8fAffected
7caa47151ab2e644dd221f741ec7578d9532c9a3 to before bf8eb1fd6110871e6232e8e7efe399276ef7e6f6Affected
7caa47151ab2e644dd221f741ec7578d9532c9a3 to before b96d7b4a9745fbd0c8384608ceb1f50415e862faAffected
7caa47151ab2e644dd221f741ec7578d9532c9a3 to before 984af1e66b4126cf145153661cc24c213e2ec231Affected

LinuxLinux

5.4Affected
before 5.4Not affected
5.4.235 through 5.4.*Not affected
5.10.173 through 5.10.*Not affected
5.15.99 through 5.15.*Not affected
6.1.16 through 6.1.*Not affected
6.2.3 through 6.2.*Not affected
6.3 and laterNot affected

References

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