CVE-2026-68287 PUBLISHED

drop_monitor: fix size calculations for 64-bit attributes

Assigner: Linux
Reserved: 30.07.2026 Published: 10.08.2026 Updated: 10.08.2026

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

drop_monitor: fix size calculations for 64-bit attributes

net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() use nla_put_u64_64bit() to append 64-bit attributes (NET_DM_ATTR_PC and NET_DM_ATTR_TIMESTAMP).

On 32-bit architectures without CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, nla_put_u64_64bit() may append a 4-byte NET_DM_ATTR_PAD attribute for 64-bit alignment.

However, net_dm_packet_report_size() and net_dm_hw_packet_report_size() used nla_total_size(sizeof(u64)) instead of nla_total_size_64bit(sizeof(u64)), budgeting 12 bytes instead of up to 16 bytes.

This under-estimation of SKB size can lead to an skb_over_panic() when __nla_reserve() or skb_put() is subsequently called.

Fix this by using nla_total_size_64bit(sizeof(u64)) in both size calculations.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from ca30707dee2bc8bc81cfd8b4277fe90f7ca6df1f to 4a9e30764e80693bcf875c776170edce20f94fe0 (excl.)
  • affected from ca30707dee2bc8bc81cfd8b4277fe90f7ca6df1f to 7089f7ab99c89f443c92d8fcc585e63f2727f0b3 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.4 is affected
  • unaffected from 0 to 5.4 (excl.)
  • unaffected from 7.1.6 to 7.1.* (incl.)
  • unaffected from 7.2-rc5 to * (incl.)

References