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CVE-2026-63831— mac802154: llsec: add skb_cow_data() before in-place crypto

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基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于在mac802154的llsec模块中对skb数据进行原地加密操作前未调用skb_cow_data()，共享数据缓冲区可能导致其他skb克隆的数据损坏、释放后重用以及内核崩溃。以下版本受到影响：3.16版本。

CVSS 8.8 · High EPSS 0.25% · P16

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 03556e4d0dbbbf4af9df76f4a3839c86f6afb015< 3a2b378b3a9ca75d3518d879148d2ad25b5714a9 affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< 7a831bcd0486788283ef35e396d4282ee01bb0d5 affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< ff976ef7c39199ebff33c18034636595016db9f0 affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< e28e7fd34c449028325322a3f5127b92594b7396 affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< 993fd674fe85d114e6a8d3963033d4fbbc2170a8 affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< bd968bdd568beacfdf98ec537a87527e85f1d0cf affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< 86d531337ea1ba02d9f2bc830d07c683d9bfaade affected
03556e4d0dbbbf4af9df76f4a3839c86f6afb015< 84a04eb5b210643bd67aab81ff805d32f62aa865 affected
… +10 more rows
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I. Basic Information for CVE-2026-63831

Vulnerability Information
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Vulnerability Title
mac802154: llsec: add skb_cow_data() before in-place crypto
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: mac802154: llsec: add skb_cow_data() before in-place crypto llsec_do_encrypt_unauth(), llsec_do_encrypt_auth(), llsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform in-place cryptographic transformations on skb data. They build a scatterlist with sg_init_one() pointing into the skb's linear data area and then pass the same scatterlist as both src and dst to the crypto API (e.g. crypto_skcipher_encrypt/decrypt, crypto_aead_encrypt/decrypt). On the RX path, __ieee802154_rx_handle_packet() clones the received skb before handing it to each subscriber via ieee802154_subif_frame(). The cloned skb shares the same underlying data buffer via reference counting. When llsec_do_decrypt() subsequently modifies this shared buffer in place, it corrupts data that other clones -- potentially belonging to other sockets or subsystems -- still reference. On the TX path, similar data sharing can occur when an skb's head has been cloned (skb_cloned() returns true). The fix is to call skb_cow_data() before performing any in-place crypto operation. skb_cow_data() ensures that the skb's data area is not shared: if the skb head is cloned or the data spans multiple fragments, it copies the data into a private buffer that can be safely modified in place. This is the same pattern used by: - ESP (net/ipv4/esp4.c, net/ipv6/esp6.c) - MACsec (drivers/net/macsec.c) - WireGuard (drivers/net/wireguard/receive.c) - TIPC (net/tipc/crypto.c) Without this guard, in-place crypto on shared skb data leads to: - Silent data corruption of other skb clones - Use-after-free when the crypto API scatterwalk writes through a page that has already been freed by another clone's kfree_skb() - Kernel crashes under concurrent 802.15.4 traffic with security enabled (KASAN/KMSAN reports slab-use-after-free) Found by 0sec (https://0sec.ai) using automated source analysis.
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基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于在mac802154的llsec模块中对skb数据进行原地加密操作前未调用skb_cow_data()，共享数据缓冲区可能导致其他skb克隆的数据损坏、释放后重用以及内核崩溃。以下版本受到影响：3.16版本。
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 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 ~ 3a2b378b3a9ca75d3518d879148d2ad25b5714a9 -
Linux Linux 3.16 -

II. Public POCs for CVE-2026-63831

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III. Intelligence Information for CVE-2026-63831

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Patches & Fixes for CVE-2026-63831 (6)

Other References for CVE-2026-63831 (1)

Same Patch Batch · Linux · 2026-07-19 · 429 CVEs total

CVE-2026-63795 10.0 CRITICAL 9p: avoid putting oldfid in p9_client_walk() error path
CVE-2026-64089 9.8 CRITICAL batman-adv: tt: fix negative last_changeset_len
CVE-2026-53398 9.8 CRITICAL NFSD: Fix SECINFO_NO_NAME decode error cleanup
CVE-2026-63984 9.8 CRITICAL ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()
CVE-2026-64025 9.8 CRITICAL bpf, skmsg: fix verdict sk_data_ready racing with ktls rx
CVE-2026-63979 9.8 CRITICAL net/handshake: hand off the pinned file reference to accept_doit
CVE-2026-64033 9.8 CRITICAL RDMA/rtrs: Fix use-after-free in path file creation cleanup
CVE-2026-64056 9.8 CRITICAL net: ethernet: cortina: Make RX SKB per-port
CVE-2026-63800 9.8 CRITICAL pNFS: Fix use-after-free in pnfs_update_layout()
CVE-2026-63978 9.8 CRITICAL net/handshake: Drain pending requests at net namespace exit
CVE-2026-64055 9.8 CRITICAL net: ethernet: cortina: Carry over frag counter
CVE-2026-63808 9.8 CRITICAL exfat: fix potential use-after-free in exfat_find_dir_entry()
CVE-2026-63888 9.8 CRITICAL scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd()
CVE-2026-63887 9.8 CRITICAL scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf
CVE-2026-64113 9.8 CRITICAL ixgbevf: fix use-after-free in VEPA multicast source pruning
CVE-2026-63886 9.8 CRITICAL scsi: target: iscsi: Validate CHAP_R length before base64 decode
CVE-2026-64162 9.8 CRITICAL idpf: fix read_dev_clk_lock spinlock init in idpf_ptp_init()
CVE-2026-64035 9.8 CRITICAL igc: set tx buffer type for SMD frames
CVE-2026-64150 9.8 CRITICAL netfilter: nft_inner: release local_lock before re-enabling softirqs
CVE-2026-63922 9.8 CRITICAL ipv6: exthdrs: refresh nh after handling HAO option

Showing top 20 of 429 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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