CVE-2025-21680 pktgen: Avoid out-of-bounds access in get_imix_entries
A local attacker can trigger an out-of-bounds write in the Linux kernel pktgen module, potentially causing a crash or arbitrary code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-21680?
CVE-2025-21680 is a high-severity memory corruption vulnerability in Linux kernel, published on 31 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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 ]
Weakness: CWE-129
Which versions are affected by CVE-2025-21680?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21680?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-21680 being exploited?
There is no known exploitation of CVE-2025-21680 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-56375, AZL-56406, BELL-CVE-2025-21680, DEBIAN-CVE-2025-21680, GHSA-8qfw-mmqm-63gq, UBUNTU-CVE-2025-21680.