CVE-2026-23204

Summary

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

net/sched: cls_u32: use skb_header_pointer_careful()

skb_header_pointer() does not fully validate negative @offset values.

Use skb_header_pointer_careful() instead.

GangMin Kim provided a report and a repro fooling u32_classify():

BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0 net/sched/cls_u32.c:221

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 66e4b63d61c15de6ca5332d9ca6db59a404d7136affected
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 29681ed51e737be14d18ecd1c304c57002e4b72caffected
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < cfa745830e45ecb75c061aa34330ee0cac941cc7affected
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 13336a6239b9d7c6e61483017bb8bdfe3ceb10a5affected
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < e41a23e61259f5526af875c3b86b3d42a9bae0e5affected
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 8a672f177ebe19c93d795fbe967846084fbc7943affected
LinuxLinuxfbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < cabd1a976375780dabab888784e356f574bbaed8affected
LinuxLinux2.6.35affected
LinuxLinux0 < 2.6.35unaffected
LinuxLinux5.10.260 <= 5.10.*unaffected
LinuxLinux5.15.209 <= 5.15.*unaffected
LinuxLinux6.1.167 <= 6.1.*unaffected
LinuxLinux6.6.124 <= 6.6.*unaffected
LinuxLinux6.12.70 <= 6.12.*unaffected
LinuxLinux6.18.10 <= 6.18.*unaffected
LinuxLinux6.19 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

References