Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-31629— nfc: llcp: add missing return after LLCP_CLOSED checks

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.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于nfc_llcp_recv_hdlc和nfc_llcp_recv_disc函数在LLCP_CLOSED状态后缺少返回语句，导致双重释放和引用计数下溢，进而引发释放后重用。

CVSS 8.8 · High EPSS 0.36% · P28

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

Affected Version Matrix 20

VendorProduct Version RangeStatus
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a< b2a23529593d011fb433a3d711fc597ed6a6bd2f affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< 665315df9c3486cb213fc44d83cc8bcd47fe0d26 affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< 9b49e2a4b8219a2fc5cebf94f4ec34e509aff8a6 affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< 0eb1263a3b8c36418c9ba295c9ab3abed664edbf affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< 796e0cac058252d0ad34ebe288e6f7979b5fc9b2 affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< 8977fad2b3c6eefd414131168d597c5d1d5e1abf affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< ff3d9e8f7244293e303f7b6ef70774291c7c27e9 affected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a< aba4712e8f0381cd5d196534ce2ad082626a5ab6 affected
… +12 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-31629

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
nfc: llcp: add missing return after LLCP_CLOSED checks
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: add missing return after LLCP_CLOSED checks In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket state is LLCP_CLOSED, the code correctly calls release_sock() and nfc_llcp_sock_put() but fails to return. Execution falls through to the remainder of the function, which calls release_sock() and nfc_llcp_sock_put() again. This results in a double release_sock() and a refcount underflow via double nfc_llcp_sock_put(), leading to a use-after-free. Add the missing return statements after the LLCP_CLOSED branches in both functions to prevent the fall-through.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于nfc_llcp_recv_hdlc和nfc_llcp_recv_disc函数在LLCP_CLOSED状态后缺少返回语句，导致双重释放和引用计数下溢，进而引发释放后重用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a ~ b2a23529593d011fb433a3d711fc597ed6a6bd2f -
Linux Linux 3.3 -

II. Public POCs for CVE-2026-31629

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-31629

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-31629 (5)

Same Patch Batch · Linux · 2026-04-24 · 138 CVEs total

CVE-2026-31637 9.8 CRITICAL rxrpc: reject undecryptable rxkad response tickets
CVE-2026-31659 9.8 CRITICAL batman-adv: reject oversized global TT response buffers
CVE-2026-31536 9.8 CRITICAL smb: server: let send_done handle a completion without IB_SEND_SIGNALED
CVE-2026-31657 9.8 CRITICAL batman-adv: hold claim backbone gateways by reference
CVE-2026-31649 9.8 CRITICAL net: stmmac: fix integer underflow in chain mode
CVE-2026-31609 9.8 CRITICAL smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
CVE-2026-31608 9.8 CRITICAL smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list
CVE-2026-31589 9.8 CRITICAL mm: call ->free_folio() directly in folio_unmap_invalidate()
CVE-2026-31607 9.8 CRITICAL usbip: validate number_of_packets in usbip_pack_ret_submit()
CVE-2026-31633 9.8 CRITICAL rxrpc: Fix integer overflow in rxgk_verify_response()
CVE-2026-31668 9.8 CRITICAL seg6: separate dst_cache for input and output paths in seg6 lwtunnel
CVE-2026-31669 9.8 CRITICAL mptcp: fix slab-use-after-free in __inet_lookup_established
CVE-2026-31636 9.1 CRITICAL rxrpc: fix RESPONSE authenticator parser OOB read
CVE-2026-31570 8.8 HIGH can: gw: fix OOB heap access in cgw_csum_crc8_rel()
CVE-2026-31588 8.8 HIGH KVM: x86: Use scratch field in MMIO fragment to hold small write values
CVE-2026-31553 8.8 HIGH KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()
CVE-2026-31622 8.8 HIGH NFC: digital: Bounds check NFC-A cascade depth in SDD response handler
CVE-2026-31558 8.8 HIGH LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
CVE-2026-31611 8.6 HIGH ksmbd: require 3 sub-authorities before reading sub_auth[2]
CVE-2026-31631 8.2 HIGH rxrpc: Fix buffer overread in rxgk_do_verify_authenticator()

Showing top 20 of 138 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-31629

No comments yet

Leave a comment