vulnerability
Ubuntu: (CVE-2023-53783): linux vulnerability
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:L/AC:L/Au:S/C:N/I:N/A:C) | Dec 9, 2025 | Dec 11, 2025 | Dec 17, 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
Solutions
References
- CVE-2023-53783
- https://attackerkb.com/topics/CVE-2023-53783
- URL-https://git.kernel.org/linus/984af1e66b4126cf145153661cc24c213e2ec231
- URL-https://git.kernel.org/stable/c/3538ade9d8c2ba41088e395de916f2599fadba8f
- URL-https://git.kernel.org/stable/c/6e291810fe83a384700eb24a1f714966391ed562
- URL-https://git.kernel.org/stable/c/984af1e66b4126cf145153661cc24c213e2ec231
- URL-https://git.kernel.org/stable/c/9e8bf9f95f7a299fa9ea45b678d001806ad5e12c
- URL-https://git.kernel.org/stable/c/b96d7b4a9745fbd0c8384608ceb1f50415e862fa
- URL-https://git.kernel.org/stable/c/bf8eb1fd6110871e6232e8e7efe399276ef7e6f6
- URL-https://www.cve.org/CVERecord?id=CVE-2023-53783
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