CVE-2023-53222

jfs: jfs_dmap: Validate db_l2nbperpage while mounting

State: Published
Severity: 7.8 High
Published: Sep 15, 2025
Updated: Aug 5, 2026
Reserved: Sep 15, 2025

Description

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

jfs: jfs_dmap: Validate db_l2nbperpage while mounting

In jfs_dmap.c at line 381, BLKTODMAP is used to get a logical block number inside dbFree(). db_l2nbperpage, which is the log2 number of blocks per page, is passed as an argument to BLKTODMAP which uses it for shifting.

Syzbot reported a shift out-of-bounds crash because db_l2nbperpage is too big. This happens because the large value is set without any validation in dbMount() at line 181.

Thus, make sure that db_l2nbperpage is correct while mounting.

Max number of blocks per page = Page size / Min block size => log2(Max num_block per page) = log2(Page size / Min block size) = log2(Page size) - log2(Min block size)

=> Max db_l2nbperpage = L2PSIZE - L2MINBLOCKSIZE

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux
3.1	7.1 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H	CISA-ADP

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
LinuxLinux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 8c1efe3f74a7864461b0dff281c5562154b4aa8eAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before ef5c205b6e6f8d1f18ef0b4a9832b1b5fa85f7f2Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before a4855aeb13e4ad1f23e16753b68212e180f7d848Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 47b7eaae08e8b2f25bdf37bc14d21be090bcb20fAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before de984faecddb900fa850af4df574a25b32bb93f5Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before c7feb54b113802d2aba98708769d3c33fb017254Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2a03c4e683d33d17b667418eb717b13dda1fac6bAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 11509910c599cbd04585ec35a6d5e1a0053d84c1Affected
LinuxLinux	2.6.12Affected before 2.6.12Not affected 4.14.322 through 4.14.Not affected 4.19.291 through 4.19.Not affected 5.4.251 through 5.4.Not affected 5.10.188 through 5.10.Not affected 5.15.121 through 5.15.Not affected 6.1.40 through 6.1.Not affected 6.4.5 through 6.4.*Not affected 6.5 and laterNot affected

Product

Versions

LinuxLinux

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 8c1efe3f74a7864461b0dff281c5562154b4aa8eAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before ef5c205b6e6f8d1f18ef0b4a9832b1b5fa85f7f2Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before a4855aeb13e4ad1f23e16753b68212e180f7d848Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 47b7eaae08e8b2f25bdf37bc14d21be090bcb20fAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before de984faecddb900fa850af4df574a25b32bb93f5Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before c7feb54b113802d2aba98708769d3c33fb017254Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2a03c4e683d33d17b667418eb717b13dda1fac6bAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 11509910c599cbd04585ec35a6d5e1a0053d84c1Affected

LinuxLinux

2.6.12Affected
before 2.6.12Not affected
4.14.322 through 4.14.*Not affected
4.19.291 through 4.19.*Not affected
5.4.251 through 5.4.*Not affected
5.10.188 through 5.10.*Not affected
5.15.121 through 5.15.*Not affected
6.1.40 through 6.1.*Not affected
6.4.5 through 6.4.*Not affected
6.5 and laterNot affected

References

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