Upstream information

CVE-2023-53222 at MITRE

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

SUSE information

Overall state of this security issue: Does not affect SUSE products

SUSE Bugzilla entry: 1249864 [NEW]

No SUSE Security Announcements cross referenced.

SUSE Timeline for this CVE

CVE page created: Wed Sep 17 12:14:53 2025
CVE page last modified: Thu Sep 18 18:12:10 2025