CVE-2026-97420— bpf: NUL-terminate replaced sysctl value
Quick assessment
Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
以下是该漏洞描述信息的中文翻译： 在 Linux 内核中，以下漏洞已得到解决： bpf：NUL 终止符替换后的 sysctl 值 在写入 sysctl 时， 保证传递给 proc 处理程序的缓冲区是 NUL（空字符）终止的。如果 替换了待处理的 sysctl 值，它可以直接将替换后的缓冲区传递给 proc 处理程序。然而，当前的辅助函数仅将 字节复制到该缓冲区中，而未追加 NUL 终止符，导致下游解析器存在越界访问的风险。 通过在被替换的值后追加一个 来修复此问题，以恢复预期的 sysctl 语义。由于辅助函数已经
Possible ATT&CK Techniques 1 AI
T1564.004 · NTFS File AttributesAffected Version Matrix 16
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | 32927393dc1ccd60fb2bdc05b9e8e88753761469< bfcee1f79aaefa90679ad47690107fb7682724ec |
affected |
32927393dc1ccd60fb2bdc05b9e8e88753761469< c73e4a04eedc677fe91a736d7a5db45100adba5e |
affected | ||
32927393dc1ccd60fb2bdc05b9e8e88753761469< 36d3e9f62dc2beb9299d3bb6f589cb9e07f773fe |
affected | ||
32927393dc1ccd60fb2bdc05b9e8e88753761469< 31377675c3d75603d957c08e338a9ac27e9f6cd5 |
affected | ||
32927393dc1ccd60fb2bdc05b9e8e88753761469< 76c14b10f50eb0afcc76e244562fa2d8c661e224 |
affected | ||
32927393dc1ccd60fb2bdc05b9e8e88753761469< 3b2814dd842a565fcf9cc370156e1ba9eae16239 |
affected | ||
32927393dc1ccd60fb2bdc05b9e8e88753761469< a66e3b5bacf38d6ab29fa05a9754f7a114485605 |
affected | ||
5.8 |
affected | ||
| … +8 more rows | |||
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-97420
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
bpf: NUL-terminate replaced sysctl value
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: NUL-terminate replaced sysctl value
When writing to sysctls, proc_sys_call_handler() guarantees that the
buffer passed to proc handlers is NUL-terminated. If
bpf_sysctl_set_new_value() replaces the pending sysctl value, it can
hand a replacement buffer directly to proc handlers. However, the
helper currently copies only buf_len bytes into that buffer without
appending a NUL terminator, leaving downstream parsers vulnerable to
out-of-bounds access.
Fix this by appending a '\0' after the replaced value to restore the
expected sysctl semantics. Since the helper already rejects buf_len
greater than PAGE_SIZE - 1, there is always room for the extra byte.
Reproduced in a QEMU x86_64 guest booted with KASAN while exercising
the sysctl replacement path with a cgroup/sysctl BPF program. The
reproducer targets `/proc/sys/net/core/flow_limit_cpu_bitmap`, fills
the original user write buffer with non-zero bytes, and overrides the
sysctl value so the replacement buffer lacks a terminating NUL. Under
that setup, the pre-fix kernel reported:
BUG: KASAN: slab-out-of-bounds in strnchrnul+0x72/0x90
Read of size 1 at addr ffff88800de57000 by task repro_patch3/66
CPU: 0 UID: 0 PID: 66 Comm: repro_patch3 Not tainted 7.1.0-rc3-00269-g8370ca1f87cc #6 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xa0
print_report+0xcb/0x5e0
? __virt_addr_valid+0x21d/0x3f0
? strnchrnul+0x72/0x90
? strnchrnul+0x72/0x90
kasan_report+0xca/0x100
? strnchrnul+0x72/0x90
strnchrnul+0x72/0x90
bitmap_parse+0x37/0x2e0
flow_limit_cpu_sysctl+0xc6/0x840
? __pfx_flow_limit_cpu_sysctl+0x10/0x10
? __kvmalloc_node_noprof+0x5ba/0x870
proc_sys_call_handler+0x31d/0x480
? __pfx_proc_sys_call_handler+0x10/0x10
? selinux_file_permission+0x39f/0x500
? lock_is_held_type+0x9e/0x120
vfs_write+0x98e/0x1000
...
</TASK>
The buggy address is located 0 bytes to the right of
allocated 4096-byte region [ffff88800de56000, ffff88800de57000)
With this fix applied, rerunning the same sysctl-targeted path yields
no corresponding KASAN reports.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-97420
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-97420
请登录查看更多情报信息。
Patches & Fixes for CVE-2026-97420 (7)
Same Patch Batch · Linux · 2026-09-24 · 234 CVEs total
| CVE-2026-93207 | 9.8 CRITICAL | SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry |
| CVE-2026-97413 | 9.8 CRITICAL | RDMA/rtrs-srv: Fix integer underflow in process_read and process_write |
| CVE-2026-93228 | 9.1 CRITICAL | svcrdma: Reject Write/Reply chunks with segcount 0 |
| CVE-2026-93799 | 8.8 HIGH | wifi: iwlwifi: mvm: validate sta_id in BA window status notif |
| CVE-2026-97442 | 8.8 HIGH | wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi |
| CVE-2026-97409 | 8.8 HIGH | nvme-fc: Do not cancel requests in io target before it is initialized |
| CVE-2026-93806 | 8.8 HIGH | wifi: cfg80211: validate assoc response length before status and IE access |
| CVE-2026-93793 | 8.8 HIGH | wifi: iwlwifi: mvm: validate TX_CMD response layout |
| CVE-2026-93790 | 8.8 HIGH | wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif |
| CVE-2026-93284 | 8.8 HIGH | drm/pagemap: dma-unmap pages before handling migration errors |
| CVE-2026-93280 | 8.8 HIGH | greybus: audio: bound the topology section sizes against the fetched size |
| CVE-2026-97509 | 8.8 HIGH | thunderbolt: Keep XDomain reference during the lifetime of a service |
| CVE-2026-93827 | 8.4 HIGH | virtio-fs: avoid double-free on failed queue setup |
| CVE-2026-97450 | 8.4 HIGH | ACPICA: validate handler object type in two places |
| CVE-2026-97452 | 8.4 HIGH | ACPICA: Prevent adding invalid references |
| CVE-2026-97451 | 8.4 HIGH | ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op) |
| CVE-2026-97455 | 8.4 HIGH | ACPICA: Fix use-after-free in acpi_ds_terminate_control_method() |
| CVE-2026-97433 | 8.2 HIGH | nvme: validate FDP configuration descriptor sizes |
| CVE-2026-93787 | 8.1 HIGH | smb: client: bound dirent name against end of SMB response in cifs_filldir |
| CVE-2026-93786 | 8.1 HIGH | ksmbd: preserve VFS inherited POSIX ACL mask |
Showing top 20 of 234 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Linux
-
CVE-2026-98384
bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destr -
CVE-2026-98383
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL -
CVE-2026-98382
bpf: Reject dev-bound-only programs on other devices -
CVE-2026-98381
veth: manage XDP program pointers during channel resize -
CVE-2026-98380
net/sched: reject IDR error pointers when deleting actions
Same vendor: Linux
-
CVE-2026-98384
bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destr -
CVE-2026-98383
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL -
CVE-2026-98382
bpf: Reject dev-bound-only programs on other devices -
CVE-2026-98381
veth: manage XDP program pointers during channel resize -
CVE-2026-98380
net/sched: reject IDR error pointers when deleting actions
V. Comments for CVE-2026-97420
No comments yet