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 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

• 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 (>= 5.5 < 5.10.188) • linux linux kernel (>= 5.11 < 5.15.121) • linux linux kernel (>= 5.16 < 6.1.40) • linux linux kernel (>= 6.2 < 6.4.5)