IT

Tracker / CVE-2023-53222

CVE-2023-53222

High 7.8

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

Affected products and versions

linux linux_kernel · … → 4.14.322
linux linux_kernel · 4.15 → 4.19.291
linux linux_kernel · 4.20 → 5.4.251
linux linux_kernel · 5.11 → 5.15.121
linux linux_kernel · 5.16 → 6.1.40
linux linux_kernel · 5.5 → 5.10.188
linux linux_kernel · 6.2 → 6.4.5

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References