CVE-2026-31780 PUBLISHED

wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

Assigner: Linux
Reserved: 09.03.2026 Published: 01.05.2026 Updated: 01.05.2026

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

wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

The variable valuesize is declared as u8 but accumulates the total length of all SSIDs to scan. Each SSID contributes up to 33 bytes (IEEE80211_MAX_SSID_LEN + 1), and with WILC_MAX_NUM_PROBED_SSID (10) SSIDs the total can reach 330, which wraps around to 74 when stored in a u8.

This causes kmalloc to allocate only 75 bytes while the subsequent memcpy writes up to 331 bytes into the buffer, resulting in a 256-byte heap buffer overflow.

Widen valuesize from u8 to u32 to accommodate the full range.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to 34a23fd9ddd683a03c7e8cc0ceded3e59e354b99 (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to 549f02d8ec94d39092ab6d9b103d0d6783a4b024 (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to bfbddeadd4779651403035ee177ae2f22f9f5521 (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to 9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7 (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to c97b2a00059608592ad0d86fbb813a4f8cf9464b (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to d8388614de613c28eeb659c10115060a83739924 (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to 0c7f21d8bd2f93998b72b7a7f93152336aeca4dd (excl.)
  • affected from c5c77ba18ea66aa05441c71e38473efb787705a4 to d049e56b1739101d1c4d81deedb269c52a8dbba0 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.2 is affected
  • unaffected from 0 to 4.2 (excl.)
  • unaffected from 5.10.253 to 5.10.* (incl.)
  • unaffected from 5.15.203 to 5.15.* (incl.)
  • unaffected from 6.1.168 to 6.1.* (incl.)
  • unaffected from 6.6.134 to 6.6.* (incl.)
  • unaffected from 6.12.81 to 6.12.* (incl.)
  • unaffected from 6.18.22 to 6.18.* (incl.)
  • unaffected from 6.19.12 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References