CVE-2023-52804: fs/jfs: Add validity check for db_maxag and db_agpref

Description

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

fs/jfs: Add validity check for db_maxag and db_agpref

Both db_maxag and db_agpref are used as the index of the
db_agfree array, but there is currently no validity check for
db_maxag and db_agpref, which can lead to errors.

The following is related bug reported by Syzbot:

UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:639:20
index 7936 is out of range for type 'atomic_t[128]'

Add checking that the values of db_maxag and db_agpref are valid
indexes for the db_agfree array.

Classification

CVE ID: CVE-2023-52804

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 15.26% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/a0649e2dd4a3595b5595a29d0064d047c2fae2fb
https://git.kernel.org/stable/c/ce15b0f1a431168f07b1cc6c9f71206a2db5c809
https://git.kernel.org/stable/c/32bd8f1cbcf8b663e29dd1f908ba3a129541a11b
https://git.kernel.org/stable/c/c6c8863fb3f57700ab583d875adda04caaf2278a
https://git.kernel.org/stable/c/1f74d336990f37703a8eee77153463d65b67f70e
https://git.kernel.org/stable/c/5013f8269887642cca784adc8db9b5f0b771533f
https://git.kernel.org/stable/c/dca403bb035a565bb98ecc1dda5d30f676feda40
https://git.kernel.org/stable/c/2323de34a3ae61a9f9b544c18583f71cea86721f
https://git.kernel.org/stable/c/64933ab7b04881c6c18b21ff206c12278341c72e

Timeline