CVE-2023-53222

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8c1efe3f74a7864461b0dff281c5562154b4aa8eaffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ef5c205b6e6f8d1f18ef0b4a9832b1b5fa85f7f2affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a4855aeb13e4ad1f23e16753b68212e180f7d848affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 47b7eaae08e8b2f25bdf37bc14d21be090bcb20faffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < de984faecddb900fa850af4df574a25b32bb93f5affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c7feb54b113802d2aba98708769d3c33fb017254affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2a03c4e683d33d17b667418eb717b13dda1fac6baffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 11509910c599cbd04585ec35a6d5e1a0053d84c1affected
LinuxLinux2.6.12affected
LinuxLinux0 < 2.6.12unaffected
LinuxLinux4.14.322 <= 4.14.*unaffected
LinuxLinux4.19.291 <= 4.19.*unaffected
LinuxLinux5.4.251 <= 5.4.*unaffected
LinuxLinux5.10.188 <= 5.10.*unaffected
LinuxLinux5.15.121 <= 5.15.*unaffected
LinuxLinux6.1.40 <= 6.1.*unaffected
LinuxLinux6.4.5 <= 6.4.*unaffected
LinuxLinux6.5 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References