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().

This issue is considered to be a moderate impact flaw, as the reproducer for this issue is not available to cause an Intigrity (I:L) threat. The bug could happen only if TIPC encryption being used. Being used as Inter-process Communication (IPC) service for cluster-wide operation. Actual only for latest versions of Red Hat Enterprise Linux 8 and Red Hat Enterprise Linux 9.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.