CVE-2026-63831
published 2026-07-19CVE-2026-63831: In the Linux kernel, the following vulnerability has been resolved: mac802154: llsec: add skb_cow_data() before in-place crypto llsec_do_encrypt_unauth()…
PriorityP350high8.8CVSS 3.1
AVAACLPRNUINSUCHIHAH
EPSS
0.24%
15.5th percentile
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.
Affected
9 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < 3a2b378b3a9ca75d3518d879148d2ad25b5714a9 | 3a2b378b3a9ca75d3518d879148d2ad25b5714a9 |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < 7a831bcd0486788283ef35e396d4282ee01bb0d5 | 7a831bcd0486788283ef35e396d4282ee01bb0d5 |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < ff976ef7c39199ebff33c18034636595016db9f0 | ff976ef7c39199ebff33c18034636595016db9f0 |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < e28e7fd34c449028325322a3f5127b92594b7396 | e28e7fd34c449028325322a3f5127b92594b7396 |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < 993fd674fe85d114e6a8d3963033d4fbbc2170a8 | 993fd674fe85d114e6a8d3963033d4fbbc2170a8 |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < bd968bdd568beacfdf98ec537a87527e85f1d0cf | bd968bdd568beacfdf98ec537a87527e85f1d0cf |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < 86d531337ea1ba02d9f2bc830d07c683d9bfaade | 86d531337ea1ba02d9f2bc830d07c683d9bfaade |
| linux | linux | >= 03556e4d0dbbbf4af9df76f4a3839c86f6afb015 < 84a04eb5b210643bd67aab81ff805d32f62aa865 | 84a04eb5b210643bd67aab81ff805d32f62aa865 |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat8.8HIGH
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VulDB
Linux Kernel up to 7.1.2 mac802154 use after free
vuldb·2026-07-19
CVE-2026-63831 Linux Kernel up to 7.1.2 mac802154 use after free
A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.1.2. This vulnerability affects the function llsec_do_encrypt_unauth/llsec_do_encrypt_auth/llsec_do_decrypt_unauth/llsec_do_decrypt_auth of the component mac802154. Performing a manipulation results in use after free.
This vulnerability was named CVE-2026-63831. The attack may be initiated remotely. There is no available exploit.
GHSA
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_u
ghsa_unreviewed·2026-07-19
CVE-2026-63831 [HIGH] 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_u
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 sha
Red Hat
kernel: mac802154: llsec: add skb_cow_data() before in-place crypto
vendor_redhat·2026-07-19·CVSS 8.8
CVE-2026-63831 [HIGH] CWE-820 kernel: mac802154: llsec: add skb_cow_data() before in-place crypto
kernel: mac802154: llsec: add skb_cow_data() before in-place crypto
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 referenc
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/3a2b378b3a9ca75d3518d879148d2ad25b5714a9https://git.kernel.org/stable/c/7a831bcd0486788283ef35e396d4282ee01bb0d5https://git.kernel.org/stable/c/84a04eb5b210643bd67aab81ff805d32f62aa865https://git.kernel.org/stable/c/86d531337ea1ba02d9f2bc830d07c683d9bfaadehttps://git.kernel.org/stable/c/993fd674fe85d114e6a8d3963033d4fbbc2170a8https://git.kernel.org/stable/c/bd968bdd568beacfdf98ec537a87527e85f1d0cfhttps://git.kernel.org/stable/c/e28e7fd34c449028325322a3f5127b92594b7396https://git.kernel.org/stable/c/ff976ef7c39199ebff33c18034636595016db9f0
2026-07-19
Published