NetSight
high7.8

CVE-2023-53222

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 …

Impact

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

VendorProductAffected versions
LinuxLinux Kernel
before 4.14.322
from 4.15 before 4.19.291
from 4.20 before 5.4.251
from 5.5 before 5.10.188
from 5.11 before 5.15.121
from 5.16 before 6.1.40

Weakness classification

References