CVE-2025-21680: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: pktgen: Avoid out-of-bounds access in get_imix_entries Passing a sufficient amount of imix entries leads to invalid access to the pkt_dev->imix_entries array because of the incorrect boundary check. UBSAN: array-index-out-of-bounds in net/core/pktgen.c:874:24 index 20 is out of range for type 'imix_pkt [20]' CPU: 2 PID: 1210 Comm: bash Not tainted 6.10.0-rc1 #121 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl lib/dump_stack.c:117 __ubsan_handle_out_of_bounds lib/ubsan.c:429 get_imix_entries net/core/pktgen.c:874 pktgen_if_write net/core/pktgen.c:1063 pde_write fs/proc/inode.c:334 proc_reg_write fs/proc/inode.c:346 vfs_write fs/read_write.c:593 ksys_write fs/read_write.c:644 do_syscall_64 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe arch/x86/entry/entry_64.S:130 Found by Linux Verification Center (linuxtesting.org) with SVACE. [ fp: allow to fill the array completely; minor changelog cleanup ]

Affected products

• Linux Linux Kernel: from 5.15, before 5.15.177 (fixed in 5.15.177); from 5.16, before 6.1.127 (fixed in 6.1.127); from 6.2, before 6.6.74 (fixed in 6.6.74); from 6.7, before 6.12.11 (fixed in 6.12.11); version 6.13 only

Published 2025-01-31. Last modified 2026-06-17.