CVE-2022-49551

Summary

In the Linux kernel, the following vulnerability has been resolved:

usb: isp1760: Fix out-of-bounds array access

Running the driver through kasan gives an interesting splat:

BUG: KASAN: global-out-of-bounds in isp1760_register+0x180/0x70c Read of size 20 at addr f1db2e64 by task swapper/0/1 (…) isp1760_register from isp1760_plat_probe+0x1d8/0x220 (…)

This happens because the loop reading the regmap fields for the different ISP1760 variants look like this:

for (i = 0; i < HC_FIELD_MAX; i++) { … }

Meaning it expects the arrays to be at least HC_FIELD_MAX - 1 long.

However the arrays isp1760_hc_reg_fields[], isp1763_hc_reg_fields[], isp1763_hc_volatile_ranges[] and isp1763_dc_volatile_ranges[] are dynamically sized during compilation.

Fix this by putting an empty assignment to the [HC_FIELD_MAX] and [DC_FIELD_MAX] array member at the end of each array. This will make the array one member longer than it needs to be, but avoids the risk of overwriting whatever is inside [HC_FIELD_MAX - 1] and is simple and intuitive to read. Also add comments explaining what is going on.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da9e1c06873350c99ba49a052f92de85f2c69f2 < bf2558bbdce3ab1d6bcba09f354914e4515d0a2baffected
LinuxLinux1da9e1c06873350c99ba49a052f92de85f2c69f2 < 47d39cb57e8669e507d17d9e0d067d2b3e3a87aeaffected
LinuxLinux1da9e1c06873350c99ba49a052f92de85f2c69f2 < 463bddd3ff1acf4036ddb80c34a715eb99debf46affected
LinuxLinux1da9e1c06873350c99ba49a052f92de85f2c69f2 < 26ae2c942b5702f2e43d36b2a4389cfb7d616b6aaffected
LinuxLinux5.14affected
LinuxLinux0 < 5.14unaffected
LinuxLinux5.15.46 <= 5.15.*unaffected
LinuxLinux5.17.14 <= 5.17.*unaffected
LinuxLinux5.18.3 <= 5.18.*unaffected
LinuxLinux5.19 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

References