Use After Free in Linux

CVE-2022-49017

In the Linux kernel, the following vulnerability has been resolved: tipc: re-fetch skb cb after tipc_msg_validate As the call trace shows, the original skb was freed in tipc_msg_validate(), and dereferencing the old skb cb would cause an use-after-free crash. BUG: KASAN: use-after-free in tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] Call Trace: <IRQ> tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] ... Allocated by task 47078: kmem_cache_alloc_node+0x158/0x4d0 __alloc_skb+0x1c1/0x270 tipc_buf_acquire+0x1e/0xe0 [tipc] tipc_msg_create+0x33/0x1c0 [tipc] tipc_link_build_proto_msg+0x38a/0x2100 [tipc] tipc_link_timeout+0x8b8/0xef0 [tipc] tipc_node_timeout+0x2a1/0x960 [tipc] call_timer_fn+0x2d/0x1c0 ... Freed by task 47078: tipc_msg_validate+0x7b/0x440 [tipc] tipc_crypto_rcv_complete+0x4b5/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] This patch fixes it by re-fetching the skb cb from the new allocated skb after calling tipc_msg_validate().

Vulnerability class: Use-After-Free

EPSS: 0.002 (16.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2022-49017?
CVE-2022-49017 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 8.8/10. Published 2024-10-21.
How severe is CVE-2022-49017?
High severity. CVSS v3 base score is 8.8 out of 10.