CVE-2022-50243: sctp: handle the error returned from sctp_auth_asoc_init_active_key

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-08-04
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: handle the error returned from sctp_auth_asoc_init_active_key When it returns an error from sctp_auth_asoc_init_active_key(), the active_key is actually not updated. The old sh_key will be freeed while it's still used as active key in asoc. Then an use-after-free will be triggered when sending patckets, as found by syzbot: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:132 [inline] sctp_sendmsg_to_asoc+0xbd5/0x1a20 net/sctp/socket.c:1863 sctp_sendmsg+0x1053/0x1d50 net/sctp/socket.c:2025 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 This patch is to fix it by not replacing the sh_key when it returns errors from sctp_auth_asoc_init_active_key() in sctp_auth_set_key(). For sctp_auth_set_active_key(), old active_key_id will be set back to asoc->active_key_id when the same thing happens.

Affected products

Linux kernel: from 4.19.199 before 4.19.262; from 5.4.136 before 5.4.220; from 5.10.54 before 5.10.150; from 5.13.6 before 5.14; from 5.14.1 before 5.15.75; from 5.16 before 5.19.17 — fixed in 4.19.262, 5.10.150, 5.14, 5.15.75, 5.19.17, 5.4.220

How to fix

Upgrade to a fixed version: Linux kernel 4.19.262, 5.10.150, 5.14, 5.15.75. Check the vendor advisory for mitigations.

References

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